https://hdl.handle.net/1721.1/79431 2026-04-08T21:37:25Z https://hdl.handle.net/1721.1/165054 Summary of the Fourth ALMA Phasing Project (APP) Commissioning and Science Verification Mission: 2016 April 3-8 Matthews, Lynn D.; Crew, G. B.; Fish, Vincent The primary objectives of the fourth APP CSV campaign were twofold: (1) to execute Very Long Baseline Interferometry (VLBI) observing mode (VOM) observations using Schedule Blocks (SBs); (2) to carry out the first end-to-end testing of intercontinental VLBI sessions in both Bands 3 and 6. While intercontinental VLBI fringes with ALMA have already been obtained during previous CSV campaigns (Matthews & Crew 2016b, c), those sessions were not conducted in a manner identical to future VLBI science campaigns (i.e., they used manual execution of observing commands rather than SBs) and did not involve observations of a full suite of ALMA and VLBI calibrators. Secondary objectives of the fourth CSV mission included further development work on an ALMA Phasing System (APS) graphical user interface (GUI), additional testing of the fast phasing loop (under a wider variety of weather conditions), tests of the phasing system in Band 7 (in support of an ongoing North America ALMA Study award), and the training of ALMA staff in the operation of the VOM and the APS hardware and software. This is a report of the activities of this campaign. This report was prepared to report on APP commissioning progress, provided as ALMA Technical Note #19. 2017-03-28T00:00:00Z https://hdl.handle.net/1721.1/165053 Summary of the Third ALMA Phasing Project (APP) Commissioning and Science Verification Mission: 2015 July 28-August 3 Matthews, Lynn D.; Crew, G. B. The primary objective for the third APP CSV campaign was to perform intercontinental Very Long Baseline Interferometry (VLBI) fringe tests between phased ALMA and remote stations in Band 3, Band 6, and (conditions permitting) Band 7. Secondary objectives included preparations for making the APS available to the community for ALMA Cycle 4 and training ALMA staff in the operation of the ALMA Phasing System (APS). This is a report of those activities. This report was prepared to report on APP commissioning progress, provided as ALMA Technical Note #18. 2015-09-14T00:00:00Z https://hdl.handle.net/1721.1/165052 Summary of the Second ALMA Phasing Project (APP) Commissioning and Science Verification Mission: 2015 March 24-30 Matthews, Lynn D.; Crew, G. B. The primary objective for the second APP CSV campaign was to test and characterize the phasing system, including the recent changes in the handling of the front-end delays. Secondary goals were to repeat the local VLBI test between ALMA and an antenna at the Operations Support Facility (OSF) (also attempted during the January mission) and to obtain a short VLBI recording on a calibrator source with ALMA and one or more stations operating as part of the Event Horizon Telescope (EHT) network, thus allowing demonstration of an intercontinental VLBI fringe. This is a report of the week's activities. This report was prepared to report on APP commissioning progress, provided as ALMA Technical Note #17. 2015-09-04T00:00:00Z https://hdl.handle.net/1721.1/165051 Summary of the First ALMA Phasing Project (APP) Commissioning and Science Verification Mission: 2015 January 6-13 Matthews, Lynn D.; Crew, G. B. The first Commissioning and Science Verification (CSV) mission for the ALMA Phasing Project (APP) took place during the ALMA EOC Week from 2015 January 6-13. The formal commencement of APP CSV activities followed the provisional acceptance of the APP hardware during a formal review by JAO that took place on 2014 December 11. This is a report of activities during the week. This report was prepared to report on APP commissioning progress, provided as ALMA Technical Note #16. 2015-03-29T00:00:00Z https://hdl.handle.net/1721.1/165050 ALMA North America Cycle 4 Study Project Final Report: Diversifying the Applications of the ALMA Phasing System Matthews, Lynn D.; Crew, G.; Hecht, M. H. The Atacama Millimeter/submillimeter Array (ALMA) Phasing Project (APP) produced the hardware and software modifications necessary to bring Very Long Baseline Interferometry (VLBI) capabilities to ALMA. The resulting VLBI observing mode was introduced to the science community in ALMA Cycle 4 (2017), and two VLBI science campaigns have now been carried out successfully at ALMA. The current Cycle 4 ALMA North America (NA) Study was proposed to lay the groundwork for a variety of enhancements to the ALMA Phasing System (APS) that were not within the scope of the original APP project. These include: (1) devising an improved method for the handling of baseband delays; (2) development of procedures for use of the APS on fainter astronomical sources than is presently possible; (3) development of data acquisition and correlation techniques to allow the APS to be used for spectral line VLBI experiments. These tasks were intended as preparatory steps for a future full-scale implementation project (if approved). Formal approval of this implementation work has now been granted and is funded through an ALMA Cycle 5 NA Development project known as APP “Phase 2” (APP-2). As a result, efforts to implement capabilities designed and explored under the current Cycle 4 Study, as well as a previous Cycle 3 Study award, are now underway. This report provides a status summary of Cycle 4 activities and outlines follow-on work that is continuing as part of the ongoing Cycle 5 Development efforts. 2018-09-01T00:00:00Z https://hdl.handle.net/1721.1/165049 ALMA North America Cycle 3 Study Project Final Report: Extensions and Enhancements to the ALMA Phasing System Matthews, L.; Crew, G.; Hecht, M. H. The Atacama Millimeter/submillimeter Array (ALMA) Phasing Project (APP) has successfully brought Very Long Baseline Interferometry (VLBI) to ALMA. Nine VLBI science projects were observed in 2017 during ALMA’s in augural VLBI campaign as part of Cycle 4. This marked the culmination of an international 5-year effort that involved both hardware and software contribu- tions from the APP Team to the ALMA Observatory. A Cycle 3 ALMA North America (NA) Study was proposed to enable ongoing support of VLBI at ALMA and the investigation of enhancements to the ALMA Phasing System (APS) that were not within the scope of the original APP project. These included: (1) an extension of phasing capabilities to the submilleter (Band 7); (2) an exploration of correlation techniques to compensate for the mismatch in sampling rates between ALMA and other VLBI stations; (3) prescriptions for optimization of ALMA baseband delay application; (4) defining and documenting data calibration and analysis pathways for experiments utilizing phased ALMA data. This report summarizes outcomes from the Cycle 3 Study. Work on the APP remains ongoing under a Cycle 4 Study award and will continue under a pending ALMA NA Cycle 5 Development Project that is expected to enable full implementation of the capabilities explored under the Cycle 3 and Cycle 4 Studies. 2018-05-01T00:00:00Z https://hdl.handle.net/1721.1/165048 Pulsars, Magnetars, and Transients with Phased ALMA, Final Report Cordes, James; Blackburn, Lindy; Chatterjee, Shami; Crew, Geoffrey; Devignes, Gregory; Doeleman, Shep; Kramer, Michael; Lazio, Joe; Liu, Kuo; Ransom, Scott The present study developed fast time-domain capability for the ALMA phased-array system that is needed for observations of compact objects in the Galactic center and elsewhere in the Galaxy. ALMA can provide unparalleled sensitivity to a spectral region that has been poorly explored for neutron stars. Observations at mm and sub-mm wavelengths have the potential for providing decisive observational constraints on emission processes from the magnetospheres of neutron stars. ALMA is also important for surveys for pulsars and transients in the Galactic center. This is a final report of the work performed. 2017-10-01T00:00:00Z https://hdl.handle.net/1721.1/165047 Final Report: ALMA Phasing Project Augmentation Matthews, Lynn D. This report provides a summary of activities carried out under the NA ALMA Development Fund award to augment the National Science Foundation MRI award for the ALMA Beamformer proposal, performed as the ALMA Phasing Project. 2017-05-24T00:00:00Z https://hdl.handle.net/1721.1/165046 MRI: Development of an ALMA Beamformer for Ultra High Resolution VLBI and High Frequency Phased Array Science Matthews, Lynn D. This is the final report covering the activities of the National Science Foundation MRI Award number 1126433. 2016-12-12T00:00:00Z https://hdl.handle.net/1721.1/165045 Cycle 11 VLBI Acceptance: Delay Fix Final Report Crew, Geoffrey B.; Matthews, Lynn D. This report presents details of changes to the VLBI software system made on the path to the Cycle 11 Acceptance. The principal new feature is the long-awaited "delay fix" to the APS that is presented in considerable detail here. This was proposed for a new ADF implementation project, APP2. The delay fix is a technology that allows the full 2-GHz continuum band to be used in active phasing, resulting results in a lower flux density limit for direct observation of science targets. It also allows a greater range of passive phasing targets to support weaker targets. Work on the delay fix began during Cycle 3 and is only now concluded in time for additional testing as desired in Cycle 11 and then full use in Cycle 12. Other than the delay fix, a new software device was delivered to support the new hydrogen maser, and there was the usual round of minor scripting updates in the SSR component. This report is written to present a largely self-contained history of the delay fix effort and its fruit, and it also covers the other, minor development items which are formally part of the Cycle 11 Acceptance. As the software phasing engine which supports this mode is also now the recommended engine for the APS, this document also serves to present relatively complete documentation on the final implementation of the SSR as well as TelCal sides of the APS. The underlying VOM remains as it was deployed and used in Cycle 4. 2024-08-20T00:00:00Z https://hdl.handle.net/1721.1/165044 ObsMode2022 Cycle 10 Go/No-Go Report for VLBI Capabilities Matthews, Lynn D.; Crew, Geoff; Fish, Vincent; Messias, Hugo; Titus, Mike; Krichbaum, Thomas We present here a report on the Very Long Baseline Interferometry (VLBI) development efforts under consideration at ALMA as new offerings in Cycle 10. These activities are being carried out under the ALMA North America Development Project known as the ALMA Phasing Project Phase 3 (APP3). The two VLBI priorities previously identified for Cycle 10 by the ObsMode process are: (1) spectral line VLBI with flexible tuning; (2) panchromatic VLBI for spectral line and continuum (Bands 1, 3, 6 and 7, with provisions for extension to any other band). This document provides an overview of the development, testing, and readiness of these capabilities. Some updates on minor development efforts are also provided. This report was prepared for the formal acceptance of the software required for Cycle 10. Notionally it is ALMA Technical Note #25, but not published (yet) as such. 2022-11-04T00:00:00Z https://hdl.handle.net/1721.1/165043 Cycle 8 (2021–2022) VLBI Delta Acceptance Report Crew, Geoff; Vila-Vilaro, Baltasar This report summarizes the acceptance process for VLBI which was carried out in 2021 as part of the normal Cycle 8 Acceptance and later, through the 2021–2022 preparations for the 2022 VLBI Campaigns. It reviews the hardware setup and checks that must be made at various times prior to any observations with VLBI peers. Then there is a suite of offline tests of the SB-generation that include observation simulation. There is also a suite of on-sky regression tests that exercise the ALMA Phasing System (APS). The final step of the acceptance has historically been the execution of a short “dress rehearsal” (DR) usually in January of the cycle year with the Event Horizon Telescope (EHT) to provide end-to-end validation of the system via fringes to remote peers. Collectively these tests establish that the science VLBI projects may proceed without issue. This report was prepared for the formal acceptance of the software required for Cycle 8. Notionally, it is ALMA Technical Note #24, but not published (yet) as such. 2022-02-09T00:00:00Z https://hdl.handle.net/1721.1/165018 ObsMode2021 Cycle 9 Go/No-Go Report for VLBI Capabilities Matthews, Lynn D.; Crew, Geoff; Goddi, Ciriaco; Marti-Vidal, Ivan; Titus, Mike; Fish, Vincent; Wagner, Jan; Rottmann, Helge; Pridiprihora, Yurii; Krichbaum, Thomas; Liu, Kuo; Kramer, Michael We present a status summary of the primary Very Long Baseline Interferometry (VLBI) development efforts which are under consideration at ALMA as new offerings in Cycle 9. These activities are being carried out under the ALMA North America Development Project known as the ALMA Phasing Project Phase 2 (APP2). The two VLBI priorities previously identified for Cycle 9 by the ObsMode process are: (1) a submillimeter (Band 7) VLBI observing capability and (2) a prototype spectral line VLBI mode (in Band 3 only). This document provides an overview of the development, testing, and readiness of these capabilities. Updates on other APP2 development efforts of relevance for future cycles, including the phased-array mode offered for the first time in Cycle 8, are also provided. Warning: This report contains material that is considered proprietary to the Event Horizon Telescope Collaboration (EHTC). These results may not be publicly posted, cited, or shared in any form. They are presented here with permission from EHTC Management solely for the purpose of allowing an evaluation of ALMA's performance as a VLBI station for 345 GHz (Band 7) VLBI. This report also contains ALMA EOC (test) data which are subject to ALMA's standard policies on the use of such data. We are working to ensure that the EHTC follows the ALMA guidelines (Carpenter et al., 2019) in the appropriate publication and release of data to allow follow-up work for science. This report was prepared for the formal acceptance of the software required for Cycle 9. Notionally it is ALMA Technical Note #23, but not published (yet) as such. 2021-10-26T00:00:00Z https://hdl.handle.net/1721.1/164885 APP2 Status Summary: Proposed New VLBI Capabilities for Cycle 8 Matthews, Lynn D.; Crew, Geoffrey B. This document contains material regarding the new capabilities proposed for ALMA Cycle 8. These included a passive phasing mode (for weaker sources), an ALMA Band 3 pulsar observing mode, a prototype spectral line mode, also for Band 3, and minor improvements to the code for operational reasons. In the event, the first two were accepted for a Cycle 8 that was delayed by the COVID-19 pandemic. The spectral line capability was deferred until Cycle 9. In response to reviewer questions, a modified figure was prepared and presented as an addendum. Both documents are presented here as a single PDF. This report was prepared for the formal acceptance of the software required for Cycle 8. Notionally it is ALMA Technical Note #21, but not (yet) published as such. 2019-11-21T00:00:00Z https://hdl.handle.net/1721.1/164884 Final Report: Enabling New VLBI Science with the ALMA Phasing System - Phase 3 (APP3): An ALMA North America Development Project Matthews, Lynn D.; Crew, Geoffrey B. Executive Summary: This document provides a summary of activities undertaken as part of the ALMA North America Development Project “Enabling New VLBI Science with the ALMA Phasing System - Phase 3 (APP3)”, whose period of performance ex- tended from January 17, 2022 to July 16, 2024. The successful completion of this project has resulted in the introduction of flexible tuning for ALMA very long baseline interfer- ometry (VLBI) operations, a fully flexible spectral line VLBI observing mode, and the enabling of panchromatic VLBI, allowing ALMA in principle to operate as a phased array in any available receiver band. The project also carried out a series of activities aimed at maintaining and optimizing existing VLBI infrastructure and provided training to staff at the Joint ALMA Observatory (JAO) to enable a transition to autonomous VLBI observing. A video feature and accompanying news article were produced near the conclusion of this project to make the results accessible to a broader audience. This report was prepared as a final report on the activities undertaken under the NA Development program mentioned in the abstract. 2024-07-19T00:00:00Z https://hdl.handle.net/1721.1/164864 Enabling New Science with the ALMA Phasing System - Phase 2 (APP2): An ALMA North America Development Project Matthews, L. D.; Crew, G. B. This document provides a summary of activities undertaken as part of the Cycle 5 ALMA North America Development Project “Enabling New Science with the ALMA Phasing System - Phase 2 (APP2)”, whose period of performance extended from January 1, 2018 to August 31, 2024. APP2 provided a series of enhancements to ALMA’s very long baseline interferometry (VLBI) and phased array capabilities, leading to the introduction of submillimeter (Band 7) phasing and VLBI capabilities, a passive phasing mode, a Phased Array (pulsar) observing mode, a prototype spectral line VLBI capability, an improved method of handling baseband delays, and a number of other minor system enhancements. This report was prepared as a final report on the activities undertaken under the NA Development program mentioned in the abstract. 2024-10-18T00:00:00Z https://hdl.handle.net/1721.1/164721 Cycle 7 VLBI Acceptance Report Crew, Geoff This report summarizes the acceptance process for VLBI which was carried out in early 2020 in preparation for the 2020 VLBI Campaigns. Even though the ALMA operations are suspended, the EHTC campaign has been cancelled, and the GMVA is going forwards without ALMA, it is still a useful exercise to report on the Acceptance testing that was done. This is especially true since (for a variety of reasons) the testing was more extensive this past January. It has also been several years since the initial Acceptance of VLBI for Cycle 4, and new features are finally to become available in Cycle 8, so it is reasonable to capture the state of things at this time. Going forward, it has been suggested as desirable for the Acceptance be added to the normal ALMA Acceptance process. This report thus serves to detail the sort of checks that can and should be made in the future. Some Action items are also noted for the near term. On the bright side, the system was totally ready. This report reviews the setup and on-site checks that can be made in a stand-alone ( no co-observing peers) mode. Then we present results from four VLBI sessions. For each, a CASA reduction is compared with a reduction of the VLBI data which (in three of the four cases) are correlated with participating EHTC sites. This report was prepared for the formal acceptance of the software required for ALMA Observing Cycle 7. Notionally it is ALMA Technical Note #20, but not published (yet) as such. 2020-12-09T00:00:00Z https://hdl.handle.net/1721.1/162807 Great Observatory for Long Wavelengths (GO-LoW) NIAC Phase I Final Report Knapp, Mary; Paritsky, Lenny; Kononov, Ekaterina; Kao, Melodie M. 2024-02-21T00:00:00Z https://hdl.handle.net/1721.1/154848 Beam chromaticity of EDGES-3 on lunar regolith Rogers, Alan E.E. 2023-07-25T00:00:00Z https://hdl.handle.net/1721.1/154847 Further study of the RFI in data from Devon Island in 2022 Rogers, Alan E.E. 2023-06-23T00:00:00Z https://hdl.handle.net/1721.1/154846 Study of further improvements in VNA accuracy Rogers, Alan E.E. 2023-04-26T00:00:00Z https://hdl.handle.net/1721.1/154845 Simulation of the effect of a resonant slot on the base plate at the MRO Rogers, Alan E.E. 2023-01-23T00:00:00Z https://hdl.handle.net/1721.1/154844 Preliminary analysis of the first EDGES-3 data from the MRO Rogers, Alan E.E. 2022-12-13T00:00:00Z https://hdl.handle.net/1721.1/154843 Further optimization of wire grid ground plane Rogers, Alan E.E. 2022-02-02T00:00:00Z https://hdl.handle.net/1721.1/154842 Sensitivity of low2-45 averaged over GHA to systematics Rogers, Alan E.E. 2021-11-30T00:00:00Z https://hdl.handle.net/1721.1/154831 Analysis of surveys of the 48x48m ground plane taken in November 2022 and March 2024 Rogers, Alan E.E. 2024-04-22T00:00:00Z https://hdl.handle.net/1721.1/154830 EDGES-3 RFI filter parameters for absorption data 2023_363 to 2024_087 Rogers, Alan E.E. 2024-04-04T00:00:00Z https://hdl.handle.net/1721.1/154829 2018 feature subtraction test on EDGES-3 data from 2023 day 363 to 2024 day 80 Rogers, Alan E.E. 2024-03-25T00:00:00Z https://hdl.handle.net/1721.1/154828 Test of using EDGES-3 to observe recombination line spectra below 50 MHz Rogers, Alan E.E. 2024-03-14T00:00:00Z https://hdl.handle.net/1721.1/154827 Further examination of 60 MHz resonance at GHA 4 to 6 hours at the WA Rogers, Alan E.E. 2024-03-05T00:00:00Z https://hdl.handle.net/1721.1/154826 Tests of systematics in EDGES-3 data Rogers, Alan E.E. 2024-02-20T00:00:00Z https://hdl.handle.net/1721.1/154825 Analysis of EDGES-3 vs Galactic Hour Angle (GHA) Rogers, Alan E.E. 2024-02-12T00:00:00Z https://hdl.handle.net/1721.1/154824 Analysis of the solar flare on 31 December 2023 observed by EDGES-3 at the WA Rogers, Alan E.E. 2024-01-22T00:00:00Z https://hdl.handle.net/1721.1/154823 Evidence for scintillations from 3c273 in EDGES-3 at WA Rogers, Alan E.E. 2024-01-16T00:00:00Z https://hdl.handle.net/1721.1/154822 Summary of EDGES-3 results from the WA from 2023 Rogers, Alan E.E. 2024-01-02T00:00:00Z https://hdl.handle.net/1721.1/154821 Chromaticity of EDGES dipole on 48x48m ground plane raised 1m above the ground Rogers, Alan E.E. 2023-12-21T00:00:00Z https://hdl.handle.net/1721.1/154820 FEKO simulations of close contact of wires in welded mesh ground planes Rogers, Alan E.E.; Barrett, J. 2023-12-06T00:00:00Z https://hdl.handle.net/1721.1/154819 FEKO tests of using RF switched rods to extend the low frequency coverage of EDGES-3 Rogers, Alan E.E. 2023-11-15T00:00:00Z https://hdl.handle.net/1721.1/154818 Simulations of an impedance analyzer compared with a VNA for EDGES S11 measurements Rogers, Alan E.E. 2023-11-06T00:00:00Z https://hdl.handle.net/1721.1/154817 Summary of EDGES-3 results from the WA from 2023 day 54 to 298 Rogers, Alan E.E. 2023-11-01T00:00:00Z https://hdl.handle.net/1721.1/154816 FEKO simulations of loop antenna for scanning welding slots for resonances Rogers, Alan E.E. 2023-10-18T00:00:00Z https://hdl.handle.net/1721.1/154815 Study of the source of occasional strong RFI bursts in EDGES data Rogers, Alan E.E. 2023-10-10T00:00:00Z https://hdl.handle.net/1721.1/154814 Further examination of potential resonances in the 48x48m ground plane at the WA Rogers, Alan E.E. 2023-10-04T00:00:00Z https://hdl.handle.net/1721.1/154813 Ionospheric Scintillation Vierinen, Juha; Rogers, Alan E.E. 2023-09-18T00:00:00Z https://hdl.handle.net/1721.1/154812 Evidence for scintillations of Cas A as the source of spiky data from Devon Island Rogers, Alan E.E.; Vierinen, Juha 2023-09-18T00:00:00Z https://hdl.handle.net/1721.1/154811 Simulations of the use of scaled antennas for global 21-cm measurements Rogers, Alan E.E. 2023-09-29T00:00:00Z https://hdl.handle.net/1721.1/154810 A test of the effect of feedback on the 21-cm absorption measurements of EDGES Rogers, Alan E.E. 2023-08-31T00:00:00Z https://hdl.handle.net/1721.1/154809 Satellite reflections of FM radio may explain additional RFI in FM band Rogers, Alan E.E. 2023-08-16T00:00:00Z https://hdl.handle.net/1721.1/154808 Tests of filtering parameters for optimum EDGES-3 calibration Rogers, Alan E.E. 2023-08-07T00:00:00Z https://hdl.handle.net/1721.1/154807 Examination of possible 60 MHz resonance at GHA 4 to 6 hours at the MRO Rogers, Alan E.E. 2023-07-12T00:00:00Z https://hdl.handle.net/1721.1/154806 21-cm absorption from Devon Island using better RFI filtering Rogers, Alan E.E. 2023-06-01T00:00:00Z https://hdl.handle.net/1721.1/154805 EDGES-3 RFI filter parameters for absorption data 2023_054 to 2023_135 Rogers, Alan E.E. 2023-05-30T00:00:00Z https://hdl.handle.net/1721.1/154804 Tests of filtering EDGES-3 data from the MRO in 2023 Rogers, Alan E.E. 2023-05-12T00:00:00Z https://hdl.handle.net/1721.1/154803 Re-examination of potential sites for global 21-cm systems Rogers, Alan E.E. 2023-04-06T00:00:00Z https://hdl.handle.net/1721.1/154802 Summary of tests of the sensitivity of EDGES-3 to systematics Rogers, Alan E.E. 2023-04-03T00:00:00Z https://hdl.handle.net/1721.1/154801 Effect of an adjacent ground plane on EDGES-3 beam chromaticity Rogers, Alan E.E. 2023-03-20T00:00:00Z https://hdl.handle.net/1721.1/154800 Analysis of EDGES-3 data from MRO following averaging of the VNA s1p data Rogers, Alan E.E. 2023-03-20T00:00:00Z https://hdl.handle.net/1721.1/154799 Averaging of VNA s11 measurements to reduce error Alan E.E. Rogers, J. Barrett, R. Cappallo 2023-03-13T00:00:00Z https://hdl.handle.net/1721.1/154798 Simulations of adding rods to broaden the bandwidth of the EDGES-3 antenna Rogers, Alan E.E. 2023-02-21T00:00:00Z https://hdl.handle.net/1721.1/154797 Simulations of extending antenna box covers for improved S11 of EDGES-3 Rogers, Alan E.E. 2023-02-06T00:00:00Z https://hdl.handle.net/1721.1/154796 Possible resonance at 75 MHz in EDGES-3 at the MRO Rogers, Alan E.E. 2023-01-17T00:00:00Z https://hdl.handle.net/1721.1/154795 MRO EDGES-3 Installation, November 2022 J. Barrett, R. Cappallo, K. Wilson 2023-01-10T00:00:00Z https://hdl.handle.net/1721.1/154794 Further analysis of EDGES-3 on 48x48m ground plane at the MRO Rogers, Alan E.E. 2023-01-03T00:00:00Z https://hdl.handle.net/1721.1/154793 Short duration RFI bursts observed with EDGES-3 at the MRO Rogers, Alan E.E. 2023-01-03T00:00:00Z https://hdl.handle.net/1721.1/154792 Time filtering of EDGES-3 data from Devon Island Rogers, Alan E.E. 2022-11-14T00:00:00Z https://hdl.handle.net/1721.1/154791 MRO air circulation and insulation assembly Steen, Parker 2022-10-31T00:00:00Z https://hdl.handle.net/1721.1/154790 RFI from digital TV and FM at Devon Island Rogers, Alan E.E. 2022-10-18T00:00:00Z https://hdl.handle.net/1721.1/154789 Simulations of the effects of DC power lines on EDGES-3 beam and S11 Rogers, Alan E.E. 2022-10-12T00:00:00Z https://hdl.handle.net/1721.1/154788 Contact corrosion as a probable cause of intermittent S11 observed at Devon Island Rogers, Alan E.E. 2022-09-30T00:00:00Z https://hdl.handle.net/1721.1/154787 Preliminary analysis of EDGES-3 data taken on Devon Island Rogers, Alan E.E. 2022-09-26T00:00:00Z https://hdl.handle.net/1721.1/154786 Devon Island Deployment Log – August 2022 Barrett, J.; Cappallo, R.; SooHoo, J. 2022-08-28T00:00:00Z https://hdl.handle.net/1721.1/154785 FEKO modeling ground loss for layered soil in the arctic Rogers, Alan E.E. 2022-07-25T00:00:00Z https://hdl.handle.net/1721.1/154784 Simulations of the length and loss of the cables used in noise wave calibration Rogers, Alan E.E. 2022-06-21T00:00:00Z https://hdl.handle.net/1721.1/154783 Proposed ground plane and set-up deployment Haughton crater Devon Island Rogers, Alan E.E. 2022-06-02T00:00:00Z https://hdl.handle.net/1721.1/154782 Software for EDGES-3 and information for deployment on Devon Island Rogers, Alan E.E. 2022-07-27T00:00:00Z https://hdl.handle.net/1721.1/154781 The effects of a raised ground plane Rogers, Alan E.E. 2022-05-11T00:00:00Z https://hdl.handle.net/1721.1/154780 Proposed wire grid ground plane for deployment in the arctic Rogers, Alan E.E. 2022-04-19T00:00:00Z https://hdl.handle.net/1721.1/154779 VHF Ny Alesund Radio Survey Huyghebaert, D.; Vierinen, Juha 2022-03-30T00:00:00Z https://hdl.handle.net/1721.1/154778 Ground plane designs for deployment of EDGES-3 in the tundra Rogers, Alan E.E. 2022-03-07T00:00:00Z https://hdl.handle.net/1721.1/154777 Haystack EDGES processing pipeline Rogers, Alan E.E. 2022-02-08T00:00:00Z https://hdl.handle.net/1721.1/154776 Sensitivity of beam chromaticity to antenna azimuth Rogers, Alan E.E. 2022-02-08T00:00:00Z https://hdl.handle.net/1721.1/154775 RFI monitor test Rogers, Alan E.E.; Barrett, J.; Wilson, K. 2022-01-24T00:00:00Z https://hdl.handle.net/1721.1/154774 Specifications for deployment of EDGES-3 at a new site Rogers, Alan E.E. 2022-01-25T00:00:00Z https://hdl.handle.net/1721.1/154773 Simulations of EDGES-3 noise and comparison with data using antenna simulator Rogers, Alan E.E. 2022-01-03T00:00:00Z https://hdl.handle.net/1721.1/154772 Tests and checks of low2-45 2020_058 to 2021_195 GHA 5 to 7 hrs Rogers, Alan E.E. 2021-12-16T00:00:00Z https://hdl.handle.net/1721.1/154771 Simulations of calibration and tests of sensitivity to sources of error Rogers, Alan E.E. 2021-12-13T00:00:00Z https://hdl.handle.net/1721.1/154770 Simulations on the effects of trees and other scattering structures near antenna Rogers, Alan E.E. 2021-12-07T00:00:00Z https://hdl.handle.net/1721.1/154769 Comparison of welded mesh and meandering wire grid ground planes Rogers, Alan E.E. 2021-12-07T00:00:00Z https://hdl.handle.net/1721.1/154768 Possible explanations for the differences between the simulations and lowband1 at LST 13 hours Rogers, Alan E.E. 2021-11-23T00:00:00Z https://hdl.handle.net/1721.1/154767 EDGES-3 at West Forks Maine and limits of internally generated RFI Barrett, J.; Rogers, Alan E.E.; Wilson, K. 2021-11-09T00:00:00Z https://hdl.handle.net/1721.1/154766 FEKO simulations of beam and loss chromaticity for lowband antenna on layered soil Rogers, Alan E.E. 2021-11-09T00:00:00Z https://hdl.handle.net/1721.1/154765 Comparison of beam and lowband1 data in 2 hour LST blocks Rogers, Alan E.E. 2021-11-03T00:00:00Z https://hdl.handle.net/1721.1/154764 Tests of EDGES-3 antenna input S-parameters Rogers, Alan E.E. 2021-10-26T00:00:00Z https://hdl.handle.net/1721.1/154763 Airflow test results and insulation mounting Steen, Parker 2021-10-26T00:00:00Z https://hdl.handle.net/1721.1/154762 Simulations of effects of scattering on absorption search with antenna with small groundplane Rogers, Alan E.E. 2021-10-14T00:00:00Z https://hdl.handle.net/1721.1/154761 FEKO simulations of ground loss for small ground planes Rogers, Alan E.E. 2021-10-14T00:00:00Z https://hdl.handle.net/1721.1/154760 Tests of EDGES-3 calibration and VNA measurement accuracy Rogers, Alan E.E. 2021-09-30T00:00:00Z https://hdl.handle.net/1721.1/154759 Dependence of sensitivity to VNA delay error on antenna and LNA s11 Rogers, Alan E.E. 2021-09-20T00:00:00Z https://hdl.handle.net/1721.1/154758 Repeatability and accuracy of EDGES-3 automated calibration Rogers, Alan E.E. 2021-08-30T00:00:00Z https://hdl.handle.net/1721.1/154757 Two tone test of EDGES-3 Rogers, Alan E.E. 2021-07-28T00:00:00Z https://hdl.handle.net/1721.1/154756 Thermal test results of antenna insulation Steen, Parker 2021-07-20T00:00:00Z https://hdl.handle.net/1721.1/154755 Study of EDGES-3 out of band noise Rogers, Alan E.E. 2021-07-22T00:00:00Z https://hdl.handle.net/1721.1/154754 Automated tests of VNA warm-up needed for highest accuracy Rogers, Alan E.E. 2021-06-24T00:00:00Z https://hdl.handle.net/1721.1/154753 Photogrammetric mapping of low2 ground plane Rogers, Alan E.E. 2021-06-15T00:00:00Z https://hdl.handle.net/1721.1/154752 Tests of automated calibration self-checks using EDGES-3 Rogers, Alan E.E. 2021-06-03T00:00:00Z https://hdl.handle.net/1721.1/154751 Formula for fractional ripple from scattering Rogers, Alan E.E. 2021-05-11T00:00:00Z https://hdl.handle.net/1721.1/154750 Tests of averaging over GHA Rogers, Alan E.E. 2021-04-27T00:00:00Z https://hdl.handle.net/1721.1/154749 Considerations for using a small metal ground plane on soil ground plane offsets Rogers, Alan E.E. 2021-03-23T00:00:00Z https://hdl.handle.net/1721.1/154748 Simulations of 30x30m uneven ground plane with random panel offsets Rogers, Alan E.E. 2021-03-11T00:00:00Z https://hdl.handle.net/1721.1/154747 Effects of a tilted and uneven ground plane vs Galactic Hour Angle Rogers, Alan E.E. 2021-03-01T00:00:00Z https://hdl.handle.net/1721.1/154746 The sensitivity of midband to ground plane tilt and deviations from flatness Rogers, Alan E.E. 2021-02-23T00:00:00Z https://hdl.handle.net/1721.1/154745 Tests of instrumental errors on midband data from 2018 and 2020 Rogers, Alan E.E. 2021-02-18T00:00:00Z https://hdl.handle.net/1721.1/154744 Effects of tilts and sky maps on beam correction for different antennas and ground planes Rogers, Alan E.E. 2021-02-12T00:00:00Z https://hdl.handle.net/1721.1/154743 Testing VNA for I/Q crosstalk Rogers, Alan E.E. 2020-01-26T00:00:00Z https://hdl.handle.net/1721.1/154742 Measurements of the galvanized ground plane mesh permeability and ground plane loss estimate Rogers, Alan E.E. 2020-01-04T00:00:00Z https://hdl.handle.net/1721.1/154741 The effects of refraction by the troposphere and ionosphere Rogers, Alan E.E. 2020-12-15T00:00:00Z https://hdl.handle.net/1721.1/154740 Simulations of the effects of scattering on the shape and frequency dependence of the beam Rogers, Alan E.E. 2020-11-23T00:00:00Z https://hdl.handle.net/1721.1/154739 Effect of temperature difference between cable and load in an antenna simulator Rogers, Alan E.E. 2020-11-12T00:00:00Z https://hdl.handle.net/1721.1/154738 Tests of the number of terms needed to adequately model the lowband foreground Rogers, Alan E.E. 2020-11-03T00:00:00Z https://hdl.handle.net/1721.1/154737 Simulations and tests of scattering effects vs Galactic Hour Angle Rogers, Alan E.E. 2020-10-14T00:00:00Z https://hdl.handle.net/1721.1/154736 Evidence that EDGES lowband results are limited by scattering near transit of the Galactic center Rogers, Alan E.E. 2020-10-05T00:00:00Z https://hdl.handle.net/1721.1/154735 Simulations of the effects of ground plane and antenna tilts Rogers, Alan E.E. 2020-09-30T00:00:00Z https://hdl.handle.net/1721.1/154734 Modeling ferrite tiles for reducing reflections from hut Rogers, Alan E.E. 2020-09-15T00:00:00Z https://hdl.handle.net/1721.1/154733 Effects of rocks and brush southeast of low2-45 Rogers, Alan E.E. 2020-08-31T00:00:00Z https://hdl.handle.net/1721.1/154732 Simulations of reflections from objects which produce fine structure in the antenna beam Rogers, Alan E.E. 2020-08-04T00:00:00Z https://hdl.handle.net/1721.1/154731 Results of absorption search vs GHA for low1 and low2-45 Rogers, Alan E.E. 2020-07-22T00:00:00Z https://hdl.handle.net/1721.1/154730 Additional tests of sources of beam chromaticity Rogers, Alan E.E. 2020-07-14T00:00:00Z https://hdl.handle.net/1721.1/154729 Simulations of the chromaticity of the lowband antenna on an uneven ground plane Rogers, Alan E.E. 2020-07-01T00:00:00Z https://hdl.handle.net/1721.1/154728 Beam correction comparison tests using sky maps at 45 and 408 MHz and correction for antenna tilt. Rogers, Alan E.E. 2020-06-17T00:00:00Z https://hdl.handle.net/1721.1/154727 Noise and fine frequency structure in EDGES data and simulations Rogers, Alan E.E. 2020-05-28T00:00:00Z https://hdl.handle.net/1721.1/154726 Circuit model simulation of EDGES data Rogers, Alan E.E. 2020-05-14T00:00:00Z https://hdl.handle.net/1721.1/154725 Effect of I/Q crosstalk in VNA measurements Rogers, Alan E.E. 2020-05-06T00:00:00Z https://hdl.handle.net/1721.1/154724 Simulations of the self-detectability of error sources in EDGES-3 Rogers, Alan E.E. 2020-04-27T00:00:00Z https://hdl.handle.net/1721.1/154723 Tests of antenna S11 measurements Rogers, Alan E.E. 2020-04-17T00:00:00Z https://hdl.handle.net/1721.1/154722 Preliminary analysis of data from Lowband 2 on large perforated ground plane Rogers, Alan E.E. 2020-04-09T00:00:00Z https://hdl.handle.net/1721.1/154721 Antenna resistive loss estimates Rogers, Alan E.E. 2020-03-31T00:00:00Z https://hdl.handle.net/1721.1/154720 Simulations of resistive loss in galvanized mesh surrounding aluminum baseplate Rogers, Alan E.E. 2020-03-30T00:00:00Z https://hdl.handle.net/1721.1/154719 Simulations of resistive loss in galvanized steel Rogers, Alan E.E. 2020-03-16T00:00:00Z https://hdl.handle.net/1721.1/154718 Boolardy Site Visit Log – February 2020 Barrett, J. 2020-03-04T00:00:00Z https://hdl.handle.net/1721.1/154717 ADC saturation by lightning Rogers, Alan E.E. 2020-03-02T00:00:00Z https://hdl.handle.net/1721.1/154716 Insulation cover for EDGES Rogers, Alan E.E. 2020-02-24T00:00:00Z https://hdl.handle.net/1721.1/154715 Improvement in bandwidth of EDGES-3 chromaticity using a cone under the antenna Rogers, Alan E.E. 2020-02-11T00:00:00Z https://hdl.handle.net/1721.1/154714 Sensitivity simulations of EDGES-3 to VNA measurement errors Rogers, Alan E.E. 2020-01-22T00:00:00Z https://hdl.handle.net/1721.1/154713 Test of 100 ps error in VNA calibration measurement Rogers, Alan E.E. 2020-01-16T00:00:00Z https://hdl.handle.net/1721.1/154712 Estimates of RFI emissions from EDGES-3 Rogers, Alan E.E. 2020-01-06T00:00:00Z https://hdl.handle.net/1721.1/154711 Simulations of the sensitivity of systematic errors in VNA S11 measurements to LNA parameters Rogers, Alan E.E. 2020-01-06T00:00:00Z https://hdl.handle.net/1721.1/154710 Effects of adjacent ground planes and antennas Rogers, Alan E.E. 2020-01-02T00:00:00Z https://hdl.handle.net/1721.1/154709 Comparison of square circular and perforated ground planes Rogers, Alan E.E. 2019-12-11T00:00:00Z https://hdl.handle.net/1721.1/154708 Estimate of ground plane mesh and antenna loss Rogers, Alan E.E. 2019-11-26T00:00:00Z https://hdl.handle.net/1721.1/154707 Comparison of EDGES-3 on different ground planes Rogers, Alan E.E. 2019-11-20T00:00:00Z https://hdl.handle.net/1721.1/154706 Proposed air circulation for EDGES-3 at the MRO Rogers, Alan E.E. 2019-11-12T00:00:00Z https://hdl.handle.net/1721.1/154705 Optimization of EDGES-3 antenna Rogers, Alan E.E. 2019-11-04T00:00:00Z https://hdl.handle.net/1721.1/154704 Proposed air circulation system for EDGES-3 Rogers, Alan E.E. 2019-10-25T00:00:00Z https://hdl.handle.net/1721.1/154703 Estimate of meteor scatter rates and filter thresholds Rogers, Alan E.E. 2019-10-17T00:00:00Z https://hdl.handle.net/1721.1/154702 EDGES-3 test deployment at Skull Creek, Oregon Rogers, Alan E.E. 2019-09-27T00:00:00Z https://hdl.handle.net/1721.1/154701 Shielding factor from non-uniform ground Rogers, Alan E.E. 2019-09-04T00:00:00Z https://hdl.handle.net/1721.1/154700 Ground Plane Analysis for EDGES-3 Test Deployment in Oregon Bair,Ethan; Rogers, Alan E.E. 2019-08-27T00:00:00Z https://hdl.handle.net/1721.1/154699 Tests of the effects of strong RFI Rogers, Alan E.E. 2019-07-16T00:00:00Z https://hdl.handle.net/1721.1/154698 EDGES-3 Test observations at West Forks Maine Rogers, Alan E.E. 2019-07-16T00:00:00Z https://hdl.handle.net/1721.1/154697 Test of EDGES-3 using antenna simulator Rogers, Alan E.E. 2019-07-16T00:00:00Z https://hdl.handle.net/1721.1/154696 EDGES-3 Thermal Tests Rogers, Alan E.E. 2019-07-11T00:00:00Z https://hdl.handle.net/1721.1/154695 Simulations of the effects of EDGES-3 S11 corrections Rogers, Alan E.E. 2019-08-05T00:00:00Z https://hdl.handle.net/1721.1/154694 Initial Test of EDGES-3 antenna S11 Rogers, Alan E.E. 2019-06-26T00:00:00Z https://hdl.handle.net/1721.1/154693 Study of RFI generated by EDGES-3 Rogers, Alan E.E. 2019-06-10T00:00:00Z https://hdl.handle.net/1721.1/154692 Details of EDGES-3 prototype Rogers, Alan E.E. 2019-08-28T00:00:00Z https://hdl.handle.net/1721.1/154691 Estimates of isolation requirements for EDGES-3 electronics Rogers, Alan E.E. 2019-05-14T00:00:00Z https://hdl.handle.net/1721.1/154690 Simulations of EDGES-3 antenna and wire grid ground plane Rogers, Alan E.E. 2019-03-04T00:00:00Z https://hdl.handle.net/1721.1/154689 Sensitivity of the beam chromaticity midband antenna on large ground plane Rogers, Alan E.E. 2019-03-04T00:00:00Z https://hdl.handle.net/1721.1/154688 Reconnaissance of Skull Creek Reservoir area located in Catlow Valley, Oregon. Rogers, Alan E.E. 2019-01-30T00:00:00Z https://hdl.handle.net/1721.1/154687 Simulations of chromaticity effects of non-uniform soil. Rogers, Alan E.E. 2019-01-03T00:00:00Z https://hdl.handle.net/1721.1/154686 Simulations of EDGES-3 chromaticity and ground loss for potential deployment in Oregon. Rogers, Alan E.E. 2019-01-02T00:00:00Z https://hdl.handle.net/1721.1/154685 Update on aspects of the EDGES-3 antenna and electronics design. Rogers, Alan E.E. 2018-12-03T00:00:00Z https://hdl.handle.net/1721.1/154684 Comparison of different EDGES antennas. Rogers, Alan E.E. 2018-11-27T00:00:00Z https://hdl.handle.net/1721.1/154683 FEKO simulations for EDGES-3 box blade antenna. Rogers, Alan E.E. 2018-11-19T00:00:00Z https://hdl.handle.net/1721.1/154682 Comparison of ground loss from LOW3 data with FEKO model. Rogers, Alan E.E. 2018-10-25T00:00:00Z https://hdl.handle.net/1721.1/154681 Considerations for placing the electronics on the antenna. Rogers, Alan E.E. 2018-10-17T00:00:00Z https://hdl.handle.net/1721.1/154680 Comparison of vertical and horizontal antennas on soil ground. Rogers, Alan E.E. 2018-09-25T00:00:00Z https://hdl.handle.net/1721.1/154679 Signature search for midband and lowband2 vs GHA. Rogers, Alan E.E. 2018-09-05T00:00:00Z https://hdl.handle.net/1721.1/154678 Weighted least squares signature using low and midband data. Rogers, Alan E.E. 2021-06-14T00:00:00Z https://hdl.handle.net/1721.1/154677 Preliminary results from lowband antenna on highband ground plane. Rogers, Alan E.E. 2018-08-28T00:00:00Z https://hdl.handle.net/1721.1/154676 Mechanism for interconnection resonances. Rogers, Alan E.E. 2018-08-14T00:00:00Z https://hdl.handle.net/1721.1/154675 Simulations of resonances in lowband ground plane due to poor connectivity. Rogers, Alan E.E. 2018-08-06T00:00:00Z https://hdl.handle.net/1721.1/154674 Results of field measurements of noise source antenna simulator. Rogers, Alan E.E. 2018-07-17T00:00:00Z https://hdl.handle.net/1721.1/154673 Midband results using recalibrated receiver 1 from 2018_146 to 2018_174.. Rogers, Alan E.E. 2018-06-26T00:00:00Z https://hdl.handle.net/1721.1/154672 Beam chromaticity and ground loss for lowband on 5×5 m ground plane. Rogers, Alan E.E. 2018-06-21T00:00:00Z https://hdl.handle.net/1721.1/154671 Estimate of the chromaticity of the foreground reflected from the lunar surface. Rogers, Alan E.E. 2018-07-09T00:00:00Z https://hdl.handle.net/1721.1/154670 Absorption profile fitting tests on data release. Rogers, Alan E.E. 2018-04-23T00:00:00Z https://hdl.handle.net/1721.1/154669 Limitations of the MOM in calculating the antenna beam using Green’s functions for lossy ground. Rogers, Alan E.E. 2018-04-10T00:00:00Z https://hdl.handle.net/1721.1/154668 Midband results from 2017_329 to 2018_043. Rogers, Alan E.E. 2018-05-01T00:00:00Z https://hdl.handle.net/1721.1/154667 Results from the EDGES-1 antenna which is electrically small at low band. Rogers, Alan E.E. 2018-03-27T00:00:00Z https://hdl.handle.net/1721.1/154666 Evidence for intermittent antenna S11 for lowband2 data. Rogers, Alan E.E. 2020-04-24T00:00:00Z https://hdl.handle.net/1721.1/154665 Modeling of midland balun loss. Rogers, Alan E.E. 2018-02-06T00:00:00Z https://hdl.handle.net/1721.1/154664 Estimates of signature confidence for lowband data using delta Chi-squared boundaries. Rogers, Alan E.E. 2018-01-23T00:00:00Z https://hdl.handle.net/1721.1/154663 Changes of the ranking of systematics with bandwidth. Rogers, Alan E.E. 2018-01-11T00:00:00Z https://hdl.handle.net/1721.1/154662 Tests of the midband balun and connector loss. Rogers, Alan E.E. 2017-12-18T00:00:00Z https://hdl.handle.net/1721.1/154661 Initial tests of silicon dioxide cable box. Rogers, Alan E.E. 2017-12-04T00:00:00Z https://hdl.handle.net/1721.1/154660 Cancellation of 3-position switch noise bias. Rogers, Alan E.E. 2017-11-21T00:00:00Z https://hdl.handle.net/1721.1/154659 Tests of mid band antenna. Rogers, Alan E.E. 2017-11-16T00:00:00Z https://hdl.handle.net/1721.1/154658 Optimization of a mid band antenna. Rogers, Alan E.E. 2017-09-07T00:00:00Z https://hdl.handle.net/1721.1/154657 Foreground and beam chromaticity contribution to lowband spectra. Rogers, Alan E.E. 2017-09-07T00:00:00Z https://hdl.handle.net/1721.1/154656 Automated S11 measurement system calibration. Rogers, Alan E.E. 2017-08-14T00:00:00Z https://hdl.handle.net/1721.1/154655 Beam chromaticity and ground loss vs ground plane size. Rogers, Alan E.E. 2017-08-04T00:00:00Z https://hdl.handle.net/1721.1/154654 Effect of errors in the assumed S11 of calibration SOL on signature amplitude via antenna S11 error. Rogers, Alan E.E. 2017-08-04T00:00:00Z https://hdl.handle.net/1721.1/154653 The effect of galactic recombination lines on the signature. Rogers, Alan E.E. 2017-07-24T00:00:00Z https://hdl.handle.net/1721.1/154652 Lowband1 and Lowband2 signature search using lowband2 receiver calibrations at 15 and 35 C. Rogers, Alan E.E. 2017-11-21T00:00:00Z https://hdl.handle.net/1721.1/154651 Tests of the changes in signature with local time, and temperature and humidity. Rogers, Alan E.E. 2017-07-24T00:00:00Z https://hdl.handle.net/1721.1/154650 Lowband ground loss for extended ground plane from FEKO with soil dielectric. Rogers, Alan E.E. 2020-03-30T00:00:00Z https://hdl.handle.net/1721.1/154649 Effects of beam correction, loss and calibration on lowband1 data. Rogers, Alan E.E. 2017-07-18T00:00:00Z https://hdl.handle.net/1721.1/154648 Effect of using receiver calibrations made at different temperatures. Rogers, Alan E.E. 2017-07-18T00:00:00Z https://hdl.handle.net/1721.1/154647 Effects of temperature on internal loads in automated antenna S11 measurements. Rogers, Alan E.E. 2017-06-20T00:00:00Z https://hdl.handle.net/1721.1/154646 Simulations of the effects of systematics on signature detection. Rogers, Alan E.E. 2017-06-20T00:00:00Z https://hdl.handle.net/1721.1/154645 Lowband1 2017 calibration differences. Rogers, Alan E.E. 2017-06-12T00:00:00Z https://hdl.handle.net/1721.1/154644 Simulations of signature search with different number of added function. Rogers, Alan E.E. 2017-06-06T00:00:00Z https://hdl.handle.net/1721.1/154643 Simulations of signature detection with small ground plane. Rogers, Alan E.E. 2017-05-25T00:00:00Z https://hdl.handle.net/1721.1/154642 RFI excision of FM signals. Rogers, Alan E.E. 2017-05-16T00:00:00Z https://hdl.handle.net/1721.1/154641 Ranking of systematics in signature search. Rogers, Alan E.E. 2017-05-15T00:00:00Z https://hdl.handle.net/1721.1/154640 Comparison of beam models. Rogers, Alan E.E. 2017-05-10T00:00:00Z https://hdl.handle.net/1721.1/154639 Galaxy calibration of low band data. Rogers, Alan E.E. 2017-05-08T00:00:00Z https://hdl.handle.net/1721.1/154638 Sensitivity of the variation of the signature amplitude with GHA to systematics. Rogers, Alan E.E. 2017-05-08T00:00:00Z https://hdl.handle.net/1721.1/154637 Summary of lowband results and tests. Rogers, Alan E.E. 2017-05-08T00:00:00Z https://hdl.handle.net/1721.1/154636 Sensitivity of the lowband signature to RFI excision parameters. Rogers, Alan E.E. 2017-04-26T00:00:00Z https://hdl.handle.net/1721.1/154635 Detection of changes in receiver calibration. Rogers, Alan E.E. 2017-04-11T00:00:00Z https://hdl.handle.net/1721.1/154634 Sensitivity of calibration to integration time. Rogers, Alan E.E. 2017-04-10T00:00:00Z https://hdl.handle.net/1721.1/154633 Simulations of rensonances in balun shield. Rogers, Alan E.E. 2017-03-28T00:00:00Z https://hdl.handle.net/1721.1/154632 Low band signature search using only Galaxy up data. Rogers, Alan E.E. 2017-03-15T00:00:00Z https://hdl.handle.net/1721.1/154631 Sensitivity of absorption signature search on ground plane loss. Rogers, Alan E.E. 2017-03-13T00:00:00Z https://hdl.handle.net/1721.1/154630 Tests of LNA input S11 and switch contact resistance. Rogers, Alan E.E. 2017-03-13T00:00:00Z https://hdl.handle.net/1721.1/154629 Sensitivity of absorption signature search to LNA S11 error. Rogers, Alan E.E. 2017-03-08T00:00:00Z https://hdl.handle.net/1721.1/154628 Comparison of the effect of systematics in 4 and 5 term search for absorption in low band data. Rogers, Alan E.E. 2017-02-28T00:00:00Z https://hdl.handle.net/1721.1/154627 Minor changes to increase EDGES accuracy. Rogers, Alan E.E. 2017-02-23T00:00:00Z https://hdl.handle.net/1721.1/154626 Suggested improved orientation for second low band ground plane. Rogers, Alan E.E. 2017-02-21T00:00:00Z https://hdl.handle.net/1721.1/154625 Simulations of the effects of systematics on a specific absorption signature Rogers, Alan E.E. 2017-02-15T00:00:00Z https://hdl.handle.net/1721.1/154624 Recalibration of high band receiver Rogers, Alan E.E. 2017-02-15T00:00:00Z https://hdl.handle.net/1721.1/154623 Tests of the FEKO beam accuracy Rogers, Alan E.E. 2017-02-14T00:00:00Z https://hdl.handle.net/1721.1/154622 3-position switch noise bias. Rogers, Alan E.E. 2017-01-31T00:00:00Z https://hdl.handle.net/1721.1/154621 Ionospheric absorption from low band data. Rogers, Alan E.E. 2017-01-23T00:00:00Z https://hdl.handle.net/1721.1/154620 Tests of EDGES spectrometer using a noise source based on antenna simulator. Rogers, Alan E.E. 2017-01-12T00:00:00Z https://hdl.handle.net/1721.1/154619 Tests of the effects of RFI from 50 to 100 MHz. Rogers, Alan E.E. 2017-01-10T00:00:00Z https://hdl.handle.net/1721.1/154618 Tests of variations of absorption signature shape Rogers, Alan E.E. 2017-01-04T00:00:00Z https://hdl.handle.net/1721.1/154617 Amplitude of absorption signature vs Galactic Center hour angle Rogers, Alan E.E. 2016-12-29T00:00:00Z https://hdl.handle.net/1721.1/154616 Simulations of the reduction of beam effects by averaging over GHA Rogers, Alan E.E. 2016-12-27T00:00:00Z https://hdl.handle.net/1721.1/154615 Tests of the levels of Lyman alpha which lead to a flattened absorption profile Rogers, Alan E.E. 2016-12-27T00:00:00Z https://hdl.handle.net/1721.1/154614 Tests of the effect of systematics in the search for absorption signature in low band data Rogers, Alan E.E. 2016-12-19T00:00:00Z https://hdl.handle.net/1721.1/154613 Optical depth calculation Rogers, Alan E.E. 2016-12-02T00:00:00Z https://hdl.handle.net/1721.1/154612 21-cm absorption signatue for large optical depth. Rogers, Alan E.E. 2016-11-29T00:00:00Z https://hdl.handle.net/1721.1/154611 Results of measurements of an artificial antenna noise source. Rogers, Alan E.E. 2016-11-14T00:00:00Z https://hdl.handle.net/1721.1/154610 Further improvements and tests of the LNA. Rogers, Alan E.E. 2016-11-07T00:00:00Z https://hdl.handle.net/1721.1/154609 Sensitivity of spectral residuals with 3 parameters removed to systematics. Rogers, Alan E.E. 2016-10-27T00:00:00Z https://hdl.handle.net/1721.1/154608 Low band balun with slightly lower loss. Rogers, Alan E.E. 2016-10-18T00:00:00Z https://hdl.handle.net/1721.1/154607 Tests of Galaxy calibration using low band data from extended ground plane Rogers, Alan E.E. 2016-10-18T00:00:00Z https://hdl.handle.net/1721.1/154606 First dat from extended ground plane. Rogers, Alan E.E. 2016-10-04T00:00:00Z https://hdl.handle.net/1721.1/154605 RFI in low band. Rogers, Alan E.E. 2016-09-13T00:00:00Z https://hdl.handle.net/1721.1/154604 EDGES-2 low band error budget. Rogers, Alan E.E. 2016-08-30T00:00:00Z https://hdl.handle.net/1721.1/154603 Tests of fitting, filtering and averaging schemes. Rogers, Alan E.E. 2016-08-18T00:00:00Z https://hdl.handle.net/1721.1/154602 Second low band antenna and balun tests. Rogers, Alan E.E. 2017-07-11T00:00:00Z https://hdl.handle.net/1721.1/154601 Theoretical approximations for a slot antenna resonance. Rogers, Alan E.E. 2020-03-30T00:00:00Z https://hdl.handle.net/1721.1/154600 Evidence of possible resonance at 70 MHz in the low band data. Rogers, Alan E.E. 2016-07-26T00:00:00Z https://hdl.handle.net/1721.1/154599 Sensitivity to ground plane defects. Rogers, Alan E.E. 2016-07-20T00:00:00Z https://hdl.handle.net/1721.1/154598 Effect of ground plane model parameters. Rogers, Alan E.E. 2016-07-09T00:00:00Z https://hdl.handle.net/1721.1/154597 Tests of super hydrophobic coatings for dew reduction on blade antenna. Rogers, Alan E.E. 2016-06-28T00:00:00Z https://hdl.handle.net/1721.1/154596 Proposed low band ground plane design. Rogers, Alan E.E. 2016-06-15T00:00:00Z https://hdl.handle.net/1721.1/154595 Dependence of the low band spectra on the Galactic center Hour Angle (GHA). Rogers, Alan E.E. 2016-06-27T00:00:00Z https://hdl.handle.net/1721.1/154594 Tests of Galaxy calibration using low and high band data. Rogers, Alan E.E. 2016-05-31T00:00:00Z https://hdl.handle.net/1721.1/154593 Effects of different ground plane models on low band results. Rogers, Alan E.E. 2016-05-18T00:00:00Z https://hdl.handle.net/1721.1/154592 Spectral index from high and low band. Rogers, Alan E.E. 2016-05-11T00:00:00Z https://hdl.handle.net/1721.1/154591 Artificial Antenna Simulator. Rogers, Alan E.E. 2018-07-09T00:00:00Z https://hdl.handle.net/1721.1/154590 Simulations of averaging beam effects over local sidreal time and antenna orientation. Rogers, Alan E.E. 2016-05-05T00:00:00Z https://hdl.handle.net/1721.1/154589 Low band balun tube and Airline as a candidates for external validation of VNA Calibration. Rogers, Alan E.E. 2016-04-20T00:00:00Z https://hdl.handle.net/1721.1/154588 Feature at 84 MHz. Rogers, Alan E.E. 2016-10-28T00:00:00Z https://hdl.handle.net/1721.1/154587 Comparison of fine structure in the high and low band spectra. Rogers, Alan E.E. 2016-04-11T00:00:00Z https://hdl.handle.net/1721.1/154586 Simulations of the effect of the electronics hut on the low band data. Rogers, Alan E.E. 2016-04-05T00:00:00Z https://hdl.handle.net/1721.1/154585 Estimate of temperature gradient in EDGES receiver enclosure. Rogers, Alan E.E. 2016-04-28T00:00:00Z https://hdl.handle.net/1721.1/154584 Tests of the sensitivity of low band to systematics. Rogers, Alan E.E. 2016-03-28T00:00:00Z https://hdl.handle.net/1721.1/154583 Preliminary estimate of the effect of foreground polarization. Rogers, Alan E.E. 2016-03-17T00:00:00Z https://hdl.handle.net/1721.1/154582 Physical functions vs polynomial. Rogers, Alan E.E. 2016-03-09T00:00:00Z https://hdl.handle.net/1721.1/154581 Sensitivity of the frequency dependence of beam to ground plane parameters. Rogers, Alan E.E. 2016-02-29T00:00:00Z https://hdl.handle.net/1721.1/154580 Comparison of high and low band data with beam effects computed with infinite and finite ground plane. Rogers, Alan E.E. 2016-02-22T00:00:00Z https://hdl.handle.net/1721.1/154579 Comparison of frequency structure in beam and loss from simulations and EDGES data Rogers, Alan E.E. 2016-02-10T00:00:00Z https://hdl.handle.net/1721.1/154578 Contribution of the ground plane to antenna beam chromaticity Rogers, Alan E.E. 2016-01-20T00:00:00Z https://hdl.handle.net/1721.1/154577 More tests of the effects of finite ground plane Rogers, Alan E.E. 2016-01-12T00:00:00Z https://hdl.handle.net/1721.1/154576 Beam effects of finite ground plane Rogers, Alan E.E. 2016-01-04T00:00:00Z https://hdl.handle.net/1721.1/154575 Spectral Structure at the Low end of Low Band Rogers, Alan E.E. 2016-01-04T00:00:00Z https://hdl.handle.net/1721.1/154574 EDGES-2 error budget update #2 Rogers, Alan E.E. 2015-12-18T00:00:00Z https://hdl.handle.net/1721.1/154573 Model of low frequency balun compared with lab measurements of S11 Rogers, Alan E.E. 2015-12-10T00:00:00Z https://hdl.handle.net/1721.1/154572 Simulations of the sensitivity to errors in balun loss parameters Rogers, Alan E.E. 2015-11-24T00:00:00Z https://hdl.handle.net/1721.1/154571 Estimate of the effect of the Earth ground under the ground plane Rogers, Alan E.E. 2016-03-21T00:00:00Z https://hdl.handle.net/1721.1/154570 Simulations of moisture on blade antenna Rogers, Alan E.E. 2015-11-17T00:00:00Z https://hdl.handle.net/1721.1/154569 High and low band comparisons Rogers, Alan E.E. 2015-11-04T00:00:00Z https://hdl.handle.net/1721.1/154568 Checks and cross-checks of EDGES calibration Rogers, Alan E.E. 2015-11-02T00:00:00Z https://hdl.handle.net/1721.1/154567 Simulations of error sources for EDGES-2 blade antenna Rogers, Alan E.E. 2015-10-07T00:00:00Z https://hdl.handle.net/1721.1/154566 EDGES Noise Rogers, Alan E.E. 2015-09-21T00:00:00Z https://hdl.handle.net/1721.1/154565 Excision of weak broadband RFI Signals Rogers, Alan E.E. 2015-09-21T00:00:00Z https://hdl.handle.net/1721.1/154564 Comparison of two methods for Galaxy calibration Rogers, Alan E.E. 2015-09-14T00:00:00Z https://hdl.handle.net/1721.1/154563 High band results using Blade antenna Rogers, Alan E.E. 2015-09-03T00:00:00Z https://hdl.handle.net/1721.1/154562 Limits set by the foreground due to frequency dependence of the beam Rogers, Alan E.E. 2015-07-16T00:00:00Z https://hdl.handle.net/1721.1/154561 Limits of EoR signature detection imposed by systematics Rogers, Alan E.E. 2015-06-02T00:00:00Z https://hdl.handle.net/1721.1/154560 FEKO tests of slot resonances Rogers, Alan E.E. 2015-05-20T00:00:00Z https://hdl.handle.net/1721.1/154559 Preliminary results for the period 18 April to 5 May 2015 Rogers, Alan E.E. 2015-05-13T00:00:00Z https://hdl.handle.net/1721.1/154558 Tests of low band antenna at Haystack Rogers, Alan E.E. 2015-04-21T00:00:00Z https://hdl.handle.net/1721.1/154557 Minor adjustments to LNA for improved S11 below 100 MHz Rogers, Alan E.E. 2015-04-21T00:00:00Z https://hdl.handle.net/1721.1/154556 Improving the LNA performance Rogers, Alan E.E. 2015-04-14T00:00:00Z https://hdl.handle.net/1721.1/154555 General trends in antenna design for constant beam Rogers, Alan E.E. 2015-03-24T00:00:00Z https://hdl.handle.net/1721.1/154554 Proposed design of low band antenna Rogers, Alan E.E. 2015-03-10T00:00:00Z https://hdl.handle.net/1721.1/154553 Estimated effect of moisture on EDGES antenna Rogers, Alan E.E. 2015-03-04T00:00:00Z https://hdl.handle.net/1721.1/154552 Preliminary results for January 2015 deployment Rogers, Alan E.E. 2015-02-18T00:00:00Z https://hdl.handle.net/1721.1/154551 Estimates of the flux and spectral index of the quiet Sun Rogers, Alan E.E. 2015-02-18T00:00:00Z https://hdl.handle.net/1721.1/154550 Study of feature at 115 MHz Rogers, Alan E.E. 2015-02-10T00:00:00Z https://hdl.handle.net/1721.1/154549 Tests of balun loss using active cold load Rogers, Alan E.E. 2015-01-29T00:00:00Z https://hdl.handle.net/1721.1/154548 EDGES2 error budget update Rogers, Alan E.E. 2015-01-14T00:00:00Z https://hdl.handle.net/1721.1/154547 Simulation of limits imposed by frequency structure in antenna beam Rogers, Alan E.E. 2015-01-05T00:00:00Z https://hdl.handle.net/1721.1/154546 Measurements of blade antenna prototype Rogers, Alan E.E. 2015-06-08T00:00:00Z https://hdl.handle.net/1721.1/154545 Changes to EDGES antenna to minimize frequency dependence of beam Rogers, Alan E.E. 2014-12-18T00:00:00Z https://hdl.handle.net/1721.1/154544 Comparison of Blade antenna for EDGES Rogers, Alan E.E. 2014-12-18T00:00:00Z https://hdl.handle.net/1721.1/154543 Frequency dependence of the EDGES antenna beam Rogers, Alan E.E. 2014-12-01T00:00:00Z https://hdl.handle.net/1721.1/154542 EDGES Antenna Beamshift Resonance Rogers, Alan E.E. 2014-11-18T00:00:00Z https://hdl.handle.net/1721.1/154541 Preliminary results from 2014 deployment Rogers, Alan E.E. 2014-11-05T00:00:00Z https://hdl.handle.net/1721.1/154540 Measurements of EDGES-2 high band balun loss Rogers, Alan E.E. 2014-10-07T00:00:00Z https://hdl.handle.net/1721.1/154539 Laboratory tests of air circulation cooling Rogers, Alan E.E. 2014-09-22T00:00:00Z https://hdl.handle.net/1721.1/154538 Altitude dependent ionospheric absorption and electron temperature Vierinen, Juha 2014-09-16T00:00:00Z https://hdl.handle.net/1721.1/154537 Using Galactic noise variation to extract EoR revisited. Rogers, Alan E.E. 2015-05-20T00:00:00Z https://hdl.handle.net/1721.1/154536 Characterization of RFI at the UNR Gund Ranch Monsalve, Raul; Mozdzen, T. 2014-07-31T00:00:00Z https://hdl.handle.net/1721.1/154535 Weighted electron temperature in ionosphere from EDGES-2 data. Rogers, Alan E.E. 2014-06-02T00:00:00Z https://hdl.handle.net/1721.1/154534 Low order fits to the effect of antenna beam change. Rogers, Alan E.E. 2014-05-05T00:00:00Z https://hdl.handle.net/1721.1/154533 Spectral effects of LNA box on antenna beam. Rogers, Alan E.E. 2014-04-29T00:00:00Z https://hdl.handle.net/1721.1/154532 Effect of antenna resonances on beam pattern. Rogers, Alan E.E. 2014-04-14T00:00:00Z https://hdl.handle.net/1721.1/154531 Additive and multiplicative terms in foreground, ionosphere and antenna loss. Rogers, Alan E.E. 2014-03-20T00:00:00Z https://hdl.handle.net/1721.1/154530 EZNEC tests for ground plane and box cover resonances Rogers, Alan E.E. 2014-03-18T00:00:00Z https://hdl.handle.net/1721.1/154529 Iterative RFI Excision Rogers, Alan E.E. 2014-03-06T00:00:00Z https://hdl.handle.net/1721.1/154528 EDGES2 error budget Rogers, Alan E.E. 2014-09-16T00:00:00Z https://hdl.handle.net/1721.1/154527 Checks of VNA linearity Rogers, Alan E.E. 2014-02-07T00:00:00Z https://hdl.handle.net/1721.1/154526 Measurement of the loss of SOL standards Rogers, Alan E.E. 2014-12-25T00:00:00Z https://hdl.handle.net/1721.1/154525 Checks of SOL calibration standards Rogers, Alan E.E. 2014-01-22T00:00:00Z https://hdl.handle.net/1721.1/154524 Measurement of cable loss between LNA and antenna. Rogers, Alan E.E. 2014-01-15T00:00:00Z https://hdl.handle.net/1721.1/154523 Estimation of VNA accuracy for measurements antenna S11 Rogers, Alan E.E. 2014-01-13T00:00:00Z https://hdl.handle.net/1721.1/154522 Cross-check of HP85047A/8753C VNA accuracy Rogers, Alan E.E. 2014-01-09T00:00:00Z https://hdl.handle.net/1721.1/154521 Sensitivities of EDGES-2 to instrumental error Rogers, Alan E.E. 2013-12-16T00:00:00Z https://hdl.handle.net/1721.1/154520 Simple model for the temperature coefficient EDGES antenna S11 Rogers, Alan E.E. 2013-12-10T00:00:00Z https://hdl.handle.net/1721.1/154519 An examination of potential improvements Rogers, Alan E.E. 2013-10-17T00:00:00Z https://hdl.handle.net/1721.1/154518 Updated: Bench tests of cable loss between antenna and LNA Rogers, Alan E.E. 2013-11-26T00:00:00Z https://hdl.handle.net/1721.1/154517 The dependence the Roberts balun loss on antenna reflection phase Rogers, Alan E.E. 2013-11-26T00:00:00Z https://hdl.handle.net/1721.1/154516 Effect of Error in the VNA Calibration Standards, on Measured Reflection Coeffient Monsalve, Raul 2013-09-05T00:00:00Z https://hdl.handle.net/1721.1/154515 Thermal control for above ground LNA box Rogers, Alan E.E. 2013-09-09T00:00:00Z https://hdl.handle.net/1721.1/154514 Effect of VNA phase errors Rogers, Alan E.E. 2013-08-28T00:00:00Z https://hdl.handle.net/1721.1/154513 Lab tests with long integrations Rogers, Alan E.E. 2013-07-23T00:00:00Z https://hdl.handle.net/1721.1/154512 Comparative tests of EDGES-2 electronics Rogers, Alan E.E. 2013-07-11T00:00:00Z https://hdl.handle.net/1721.1/154511 Thermal Control of EDGES front-end box Rogers, Alan E.E. 2013-07-02T00:00:00Z https://hdl.handle.net/1721.1/154510 Simulations of the removal of the foreground, ionosphere and frequency dependence of the beam Rogers, Alan E.E. 2013-07-08T00:00:00Z https://hdl.handle.net/1721.1/154509 Noise analysis of an imperfect attenuator Rogers, Alan E.E. 2013-06-17T00:00:00Z https://hdl.handle.net/1721.1/154508 Characteristics and stability of EDGES electronics Rogers, Alan E.E. 2017-01-30T00:00:00Z https://hdl.handle.net/1721.1/154507 Effect of a cable impedance deviation in loss estimate Rogers, Alan E.E. 2013-04-24T00:00:00Z https://hdl.handle.net/1721.1/154506 Measurements of VNA noise and simulations of their effect on EoR estimation Rogers, Alan E.E. 2013-05-09T00:00:00Z https://hdl.handle.net/1721.1/154505 Updated: Summary EDGES processing software Rogers, Alan E.E. 2015-04-07T00:00:00Z https://hdl.handle.net/1721.1/154504 Using EDGES to correct changes in antenna ref Rogers, Alan E.E. 2013-04-22T00:00:00Z https://hdl.handle.net/1721.1/154503 Tests of the phase and impedance stability of LDF2-50A heliax cable Rogers, Alan E.E. 2013-04-09T00:00:00Z https://hdl.handle.net/1721.1/154502 Effect of moving the reference point Rogers, Alan E.E. 2013-03-28T00:00:00Z https://hdl.handle.net/1721.1/154501 Some tests of cable stability for S11 measurements Rogers, Alan E.E. 2013-03-27T00:00:00Z https://hdl.handle.net/1721.1/154500 Proposed EDGES2 installation Rogers, Alan E.E. 2013-03-12T00:00:00Z https://hdl.handle.net/1721.1/154499 Sensitivity of EDGES Antenna Propotype to Different Perturbations Monsalve, Raul 2013-03-05T00:00:00Z https://hdl.handle.net/1721.1/154498 Options and error estimates for EDGES-2 deployment Rogers, Alan E.E. 2013-01-31T00:00:00Z https://hdl.handle.net/1721.1/154497 Simulations of attenuation and delay between 3-position switch and LNA Rogers, Alan E.E. 2013-01-23T00:00:00Z https://hdl.handle.net/1721.1/154496 EDGES-2 Laboratory tests of absolute calibration Rogers, Alan E.E. 2013-01-14T00:00:00Z https://hdl.handle.net/1721.1/154495 Stability measurements of VNA, coaxial cable, and antenna with Roberts balun Monsalve, Raul 2012-12-13T00:00:00Z https://hdl.handle.net/1721.1/154494 EDGES LNA Improvements Rogers, Alan E.E. 2012-12-18T00:00:00Z https://hdl.handle.net/1721.1/154493 Simulation of the removal of the foreground and ionosphere Rogers, Alan E.E. 2013-08-27T00:00:00Z https://hdl.handle.net/1721.1/154492 Estimate of the Spectral flatness of a hot filament source. Rogers, Alan E.E. 2012-11-06T00:00:00Z https://hdl.handle.net/1721.1/154491 Preliminary estimates of EDGES-2 error sources. Rogers, Alan E.E. 2012-10-16T00:00:00Z https://hdl.handle.net/1721.1/154490 Estimate of EDGES-2 Antenna loss Rogers, Alan E.E. 2013-01-07T00:00:00Z https://hdl.handle.net/1721.1/154489 Test of absolute accuracy of N5222A VNA Rogers, Alan E.E. 2012-09-19T00:00:00Z https://hdl.handle.net/1721.1/154488 Summary of EDGES-2 calibration and processing Rogers, Alan E.E. 2012-10-10T00:00:00Z https://hdl.handle.net/1721.1/154487 Updated:EDGES antenna design notes Rogers, Alan E.E. 2012-12-10T00:00:00Z https://hdl.handle.net/1721.1/154486 Set of basis functions needed to account for EDGES systematics Rogers, Alan E.E. 2012-08-23T00:00:00Z https://hdl.handle.net/1721.1/154485 Calibration and temperature corrections for high accuracy VNA measurements Rogers, Alan E.E. 2012-09-12T00:00:00Z https://hdl.handle.net/1721.1/154484 EDGES Temperature monitor Rogers, Alan E.E. 2012-08-20T00:00:00Z https://hdl.handle.net/1721.1/154483 Simulation of EDGES.2 systematic error Rogers, Alan E.E. 2012-08-16T00:00:00Z https://hdl.handle.net/1721.1/154482 Additional calibration steps for improving VNA accuracy Rogers, Alan E.E. 2012-08-07T00:00:00Z https://hdl.handle.net/1721.1/154481 Tests of prototype Fourpoint antenna with modified Roberts balun Rogers, Alan E.E. 2012-11-06T00:00:00Z https://hdl.handle.net/1721.1/154480 Effect of ground plane size on ground loss Rogers, Alan E.E. 2014-09-15T00:00:00Z https://hdl.handle.net/1721.1/154479 The Roberts balun Rogers, Alan E.E. 2012-04-23T00:00:00Z https://hdl.handle.net/1721.1/154478 Methods for improved calibration of VNA Rogers, Alan E.E. 2012-03-29T00:00:00Z https://hdl.handle.net/1721.1/154477 Tests of EDGES calibration Rogers, Alan E.E. 2012-02-21T00:00:00Z https://hdl.handle.net/1721.1/154476 Tests of VNA accuracy Rogers, Alan E.E. 2012-02-07T00:00:00Z https://hdl.handle.net/1721.1/154475 Low loss torodial air core balun Rogers, Alan E.E. 2012-01-31T00:00:00Z https://hdl.handle.net/1721.1/154474 A laboratory test of the absolute calibration using an antenna simulator Rogers, Alan E.E. 2011-12-21T00:00:00Z https://hdl.handle.net/1721.1/154473 Initial Lab tests of absolute calibration Rogers, Alan E.E. 2011-12-06T00:00:00Z https://hdl.handle.net/1721.1/154472 Absolute calibration of sky noise spectrum using a wideband antenna Rogers, Alan E.E. 2011-09-12T00:00:00Z https://hdl.handle.net/1721.1/154471 Temperature contribution of ionosphere to the sky noise spectrum Rogers, Alan E.E. 2011-08-30T00:00:00Z https://hdl.handle.net/1721.1/154470 Noise model for balun, antenna loss and ground pickup Rogers, Alan E.E. 2011-08-11T00:00:00Z https://hdl.handle.net/1721.1/154469 Calibration sensitivity to LNA and antenna parameter errors Rogers, Alan E.E. 2011-08-11T00:00:00Z https://hdl.handle.net/1721.1/154468 Noise wave analysis using reflection coefficients referenced to 50 ohms Rogers, Alan E.E. 2011-07-27T00:00:00Z https://hdl.handle.net/1721.1/154467 Tests of EDGES calibration at West Forks Maine Rogers, Alan E.E.; Cele, D. 2011-07-27T00:00:00Z https://hdl.handle.net/1721.1/154466 Sensitivity of antenna impedance to environment change Rogers, Alan E.E.; Cele, D. 2011-07-11T00:00:00Z https://hdl.handle.net/1721.1/154465 Updated: Spectral flatness of HP346C noise source Rogers, Alan E.E.; Cele, D. 2012-07-16T00:00:00Z https://hdl.handle.net/1721.1/154464 Balun model and measurements Rogers, Alan E.E.; Cele, D. 2011-07-11T00:00:00Z https://hdl.handle.net/1721.1/154463 Effect of antenna beam pattern on the detectability of EoR Rogers, Alan E.E. 2012-03-29T00:00:00Z https://hdl.handle.net/1721.1/154462 Effect of attenuation the sensitivity of EDGES to antenna match Rogers, Alan E.E. 2011-05-25T00:00:00Z https://hdl.handle.net/1721.1/154461 Optimization of EDGES Fourpoint antenna using FEKO Rogers, Alan E.E. 2011-05-03T00:00:00Z https://hdl.handle.net/1721.1/154460 Noise Diode Tests Rogers, Alan E.E. 2011-03-16T00:00:00Z https://hdl.handle.net/1721.1/154459 Additional systematics in EDGES electronics Rogers, Alan E.E. 2011-12-07T00:00:00Z https://hdl.handle.net/1721.1/154458 Extending the EDGES frequency range to cover 40 to 190 MHz Rogers, Alan E.E. 2010-12-21T00:00:00Z https://hdl.handle.net/1721.1/154457 Preliminary results of modeling EDGES Rogers, Alan E.E. 2010-10-27T00:00:00Z https://hdl.handle.net/1721.1/154456 Model fitting functions Rogers, Alan E.E. 2010-10-06T00:00:00Z https://hdl.handle.net/1721.1/154455 Simulation of performance with LNA calibration Rogers, Alan E.E. 2010-10-06T00:00:00Z https://hdl.handle.net/1721.1/154454 EDGES LNA Optimization Rogers, Alan E.E. 2010-09-20T00:00:00Z https://hdl.handle.net/1721.1/154453 Simulations of EoR with different fitting parameters Rogers, Alan E.E. 2010-09-16T00:00:00Z https://hdl.handle.net/1721.1/154452 Extending spectrometer frequency range Rogers, Alan E.E. 2010-06-10T00:00:00Z https://hdl.handle.net/1721.1/154451 Tests of long integration using AC240 Rogers, Alan E.E. 2010-03-12T00:00:00Z https://hdl.handle.net/1721.1/154450 RFI Statistics at Boolardy Rogers, Alan E.E. 2010-12-04T00:00:00Z https://hdl.handle.net/1721.1/154449 Simulations of EoR signature detection Rogers, Alan E.E. 2010-01-12T00:00:00Z https://hdl.handle.net/1721.1/154448 Current limits of EDGES performance using DP310 Rogers, Alan E.E.; Bowman, J.D. 2010-01-08T00:00:00Z https://hdl.handle.net/1721.1/154447 More on using Galactic noise for calibration Rogers, Alan E.E. 2009-12-15T00:00:00Z https://hdl.handle.net/1721.1/154446 Meteor scatter rates Rogers, Alan E.E. 2009-12-01T00:00:00Z https://hdl.handle.net/1721.1/154445 Path loss needed to meet ITU RA769-1 Rogers, Alan E.E. 2009-11-23T00:00:00Z https://hdl.handle.net/1721.1/154444 Measurements of the spectrum from 80 to 200 MHz in the Catlow Valley Oregon Rogers, Alan E.E.; Bowman, J.D. 2009-11-09T00:00:00Z https://hdl.handle.net/1721.1/154443 Tests of AC240 spectrometer using out of band added noise Rogers, Alan E.E. 2009-10-21T00:00:00Z https://hdl.handle.net/1721.1/154442 LNA Noise Correlation Rogers, Alan E.E. 2009-09-03T00:00:00Z https://hdl.handle.net/1721.1/154441 Model of the level of systematics in DP310 Rogers, Alan E.E. 2009-07-28T00:00:00Z https://hdl.handle.net/1721.1/154440 Using Galactic noise variation to extract EoR signatures (Revised) Rogers, Alan E.E. 2009-07-27T00:00:00Z https://hdl.handle.net/1721.1/154439 Further analysis of 2009 EDGES data from Boolardy Rogers, Alan E.E. 2009-05-15T00:00:00Z https://hdl.handle.net/1721.1/154438 Theoretical noise for 3-position switching using Acqiris DP310 Rogers, Alan E.E. 2009-05-27T00:00:00Z https://hdl.handle.net/1721.1/154437 Deployment of EDGES prototype system at Murchison Radio-astronomy Observatory, Boolardy Station, Western Australia Bowman, J.D. 2009-03-18T00:00:00Z https://hdl.handle.net/1721.1/154436 Tests of EDGES DP310 12-bit ADC at Forks, Maine Rogers, Alan E.E. 2009-01-16T00:00:00Z https://hdl.handle.net/1721.1/154435 Balun with improved balance Rogers, Alan E.E. 2011-10-12T00:00:00Z https://hdl.handle.net/1721.1/154434 EDGES system using direct sampling 12-bit ADC Rogers, Alan E.E. 2009-01-07T00:00:00Z https://hdl.handle.net/1721.1/154433 Effects of digitizer non linearity Rogers, Alan E.E. 2008-10-28T00:00:00Z https://hdl.handle.net/1721.1/154432 Methods of smoothing spectra Rogers, Alan E.E. 2008-07-10T00:00:00Z https://hdl.handle.net/1721.1/154431 Tests of the global neutral hydrogen signature in the 60-150 MHz band Rogers, Alan E.E. 2008-06-09T00:00:00Z https://hdl.handle.net/1721.1/154430 Comparison of the MWA bowtie, shortwide and shortwide with stubs. Rogers, Alan E.E. 2008-02-05T00:00:00Z https://hdl.handle.net/1721.1/154429 Arrays with MWAS and modified MWA Antennas Rogers, Alan E.E. 2007-12-13T00:00:00Z https://hdl.handle.net/1721.1/154428 Expected performance of a narrowband “frequency cycled” system. Rogers, Alan E.E. 2007-09-18T00:00:00Z https://hdl.handle.net/1721.1/154427 Some notes on various switching schemes Rogers, Alan E.E. 2007-09-14T00:00:00Z https://hdl.handle.net/1721.1/154426 Local oscillator frequency cycling Rogers, Alan E.E. 2007-08-09T00:00:00Z https://hdl.handle.net/1721.1/154425 Tests of MWA antenna modification Rogers, Alan E.E. 2007-06-04T00:00:00Z https://hdl.handle.net/1721.1/154424 MWA active antenna noise simulations Rogers, Alan E.E. 2007-06-04T00:00:00Z https://hdl.handle.net/1721.1/154423 Measurements of MWA antenna impedance Rogers, Alan E.E. 2007-06-01T00:00:00Z https://hdl.handle.net/1721.1/154422 Tests of MWA LNAs Rogers, Alan E.E. 2007-06-01T00:00:00Z https://hdl.handle.net/1721.1/154421 New inexpensive approach to EDGES and SRT spectrometers Rogers, Alan E.E. 2002-04-13T00:00:00Z https://hdl.handle.net/1721.1/154420 Satellite signals in the 100 to 200 MHz band Rogers, Alan E.E. 2007-02-05T00:00:00Z https://hdl.handle.net/1721.1/154419 Defects in ADCs evident in long integrations Rogers, Alan E.E. 2007-02-05T00:00:00Z https://hdl.handle.net/1721.1/154418 Deployment of EDGES at Mileura Station, Western Australia Rogers, Alan E.E.; Bowman, J.D. 2006-12-13T00:00:00Z https://hdl.handle.net/1721.1/154417 EDGES data analysis Rogers, Alan E.E. 2006-12-18T00:00:00Z https://hdl.handle.net/1721.1/154416 Using EDGES spectrometer to measure the antenna reflection coefficient Rogers, Alan E.E. 2006-11-21T00:00:00Z https://hdl.handle.net/1721.1/154415 Estimate of ripple due to common mode reflections on cable to LNA. Rogers, Alan E.E. 2006-11-02T00:00:00Z https://hdl.handle.net/1721.1/154414 Evaluation of EDGES at West Forks, Maine Rogers, Alan E.E. 2006-09-08T00:00:00Z https://hdl.handle.net/1721.1/154413 Comparison of Galactic Noise at Potential EDGES Sites Bowman, J.D. 2006-11-02T00:00:00Z https://hdl.handle.net/1721.1/154412 EDGES Sensitivity to Galactic Radio Recombination Lines Bowman, J.D. 2006-11-02T00:00:00Z https://hdl.handle.net/1721.1/154411 Noise and error sources in 3 position switching Rogers, Alan E.E. 2006-08-28T00:00:00Z https://hdl.handle.net/1721.1/154410 Absolute sky calibration using EDGES Rogers, Alan E.E. 2006-08-17T00:00:00Z https://hdl.handle.net/1721.1/154409 Improved input match for low frequency LNA Rogers, Alan E.E. 2006-08-07T00:00:00Z https://hdl.handle.net/1721.1/154408 Correction antenna temperature for cable attenuation and antenna mismatch Rogers, Alan E.E. 2006-07-25T00:00:00Z https://hdl.handle.net/1721.1/154407 EDGES and AC240 RFI monitor parameters Rogers, Alan E.E. 2006-07-20T00:00:00Z https://hdl.handle.net/1721.1/154406 VSWR Measurements of four-point dipole antenna for EDGES Bowman, J.D. 2006-06-29T00:00:00Z https://hdl.handle.net/1721.1/154405 RFI Scout Trip to California and Nevada Bowman, J.D. 2006-11-02T00:00:00Z https://hdl.handle.net/1721.1/154404 Absolute calibration of an active antenna Rogers, Alan E.E. 2006-03-02T00:00:00Z https://hdl.handle.net/1721.1/154403 Absolute calibration of an active antenna Rogers, Alan E.E. 2006-02-14T00:00:00Z https://hdl.handle.net/1721.1/154402 Model of active antenna noise Rogers, Alan E.E. 2006-02-07T00:00:00Z https://hdl.handle.net/1721.1/154401 Active antenna for spectrum monitor and EOR Rogers, Alan E.E. 2006-02-03T00:00:00Z https://hdl.handle.net/1721.1/154400 Dipole beam change with frequency Rogers, Alan E.E. 2006-02-03T00:00:00Z https://hdl.handle.net/1721.1/154399 Tests of active antenna for RFI monitor Rogers, Alan E.E. 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/154398 Effect of the frequency of the beam patterns on EOR signature Rogers, Alan E.E. 2006-01-24T00:00:00Z https://hdl.handle.net/1721.1/154397 RFI avoidance by lowering the antenna Rogers, Alan E.E. 2006-01-11T00:00:00Z https://hdl.handle.net/1721.1/154396 Development of sensitive compact RFI/EOR monitor Rogers, Alan E.E. 2006-01-04T00:00:00Z https://hdl.handle.net/1721.1/154395 Estimate of systematic errors in search for EOR global step Rogers, Alan E.E. 2006-01-04T00:00:00Z https://hdl.handle.net/1721.1/154394 Proposed filter for detection of EOR spectral ramp Rogers, Alan E.E. 2005-12-20T00:00:00Z https://hdl.handle.net/1721.1/97679 Studies of the Midlatitude and High Latitude Ionosphere from Millstone Hill during Solar Maximum Conditions Evans, J. V.; Holt, J. M.; Oliver, W. L.; Wand, R. H. This report summarizes the work carried out at the Millstone Hill radar from April 1979 through March 1982 in studies of the earth's upper atmosphere and ionosphere with the support furnished by the National Science Foundation (Grant ATM-79-09189). Most notable were new studies of the auroral and subauroral regions of the ionosphere using a scanning technique in which the 1° beam of the UHF steerable radar is scanned at a fixed elevation (typically 4°) through 180° or 360° azimuth. This technique provides maps of the electron density, electron and ion temperatures and line-of-sight drifts at fixed altitudes as functions of invariant latitude and local time. These show a rich variety of behavior depending upon magnetic activity and season. In particular, the nighttime trough frequently is found to appear first in mid-afternoon at latitudes where the ion drift is high and sunward. Later the trough usually is found equatorwards of regions of fast convection. It is suggested that troughs may be manufactured in regions of rapid flow during substorms and then corotate with the earth as 'fossils' once the electric fields have diminished. Other studies reported herein include the analysis of the daily mean temperature, and the semidurnal temperatures and winds in the lower thermosphere as well as studies of the exospheric temperature. The report includes a detailed account of the improvements made in both the hardware and the software at the radar during the three-year period. 1982-09-01T00:00:00Z https://hdl.handle.net/1721.1/97678 Millstone Hill Thomson Scatter Results for 1974 Evans, J. V.; Holt, J. M. During 1973, the vertically-directed incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) was employed to measure electron density, electron and ion temperature and vertical ion velocity in the F-region over periods of 24 hours one or two times per month. The observations spanned the height interval 200-900 km approximately, and achieved a time resolution of about 30 minutes. This report presents the results of the measurements made using single long pulses in a set of contour diagrams. The behavior observed during these observations is discussed briefly in terms of the diurnal, seasonal, sunspot cycle, and magnetic disturbance variations reported previously and which now are believed to be largely understood. 1982-01-01T00:00:00Z https://hdl.handle.net/1721.1/97677 Millstone Hill Thomson Scatter Results for 1973 Evans, J. V.; Babcock, R. R., Jr.; Holt, J. M. During 1973, the vertically-directed incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) was employed to measure electron density, electron and ion temperature and vertical ion velocity in the F-region over periods of 24 hours one or two times per month. The observations spanned the height interval 200-900 km approximately, and achieved a time resolution of about 30 minutes. This report presents the results of these measurements in a set of contour diagrams. For a number of the days, the results have been used to derive the diurnal variation of the temperature of the neutral atmosphere above 300 km (the exospheric temperature) as well as the speed of the neutral wind in the magnetic meridian plane at this altitude. These results were used to define a model for the pressure variation in the thermosphere over Millstone whose E-W variation is set by the observed temperature variation, and whose N-S variation was adjusted to reproduce the observed winds calculated by solving momentum equations for the neutral air. These results, together with similar results obtained using data gathered over the six-year period 1970-1975 have been used in a study of the seasonal and sunspot cycle variation of the mean meridional and zonal winds. Also reported are the results of a study of the effect of magnetic storms on the thermospheric winds observed over Millstone Hill. 1979-10-22T00:00:00Z https://hdl.handle.net/1721.1/97676 Studies of the Midlatitude and High Latitude Ionosphere from Millstone Hill April 1976 - March 1979 Evans, J. V.; Holt, J. M.; Oliver, W. L.; Wand, R. H. During the period 1 April 1976 through 31 March 1979, the Millstone Hill radar facility in Westford, Massachusetts (42° N, 71.5° W) was supported for incoherent scatter studies of the earth's upper atmosphere and ionosphere by the National Science Foundation under Grant ATM 75-22193. This report describes the work carried out under this grant. 1979-09-01T00:00:00Z https://hdl.handle.net/1721.1/97675 Incoherent Scatter Measurements of E- and F-Region Density, Temperatures, and Collision Frequency at Millstone Hill Oliver, W. L.; Salah, J. E.; Wand, R. H.; Evans, J. V. The Millstone Hill incoherent (Thomson) scatter radar system has been operated since 1963 to perform a synoptic study of F2-region electron densities, and electron and ion temperatures. These measurements have been conducted by transmitting single long pulses and performing digital sweep integration and spectrum analysis of the reflected signals. This report describes changes made to the system in 1969 to permit extensions of the measurements to altitudes below 200 km (i.e., the E- and F1-regions). These changes include modifications to the radar timing equipment to permit the transmission of close-spaced pairs of pulses from which the echo autocorrelation function can be determined in the computer by processing appropriately spaced pairs of echo samples. By operating the radar coherently, it has also been possible to subtract the unwanted (stronger) clutter signals from the ionospheric echoes. Samples are presented of the results that can now be obtained from these programs. 1979-02-23T00:00:00Z https://hdl.handle.net/1721.1/97674 Millstone Hill Thomson Scatter Results for 1972 Evans, J. V.; Holt, J. M. During 1972, the vertically directed incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) was employed to measure electron density, electron and ion temperatures, and vertical ion velocity in the F-region over periods of 24 hours, one or two times per month. The observations spanned the height interval 200 to 900 km, approximately, and achieved a time resolution of about 30 minutes. This report presents the results of these measurements in a set of contour diagrams. For a number of the days, the spectra of the signals gathered at altitudes between 450 and 1125 km have been the subject of further analysis in an effort to determine the percentage of H[superscript +] ions present over Millstone. The results suggest that H[superscript +] ions are escaping from the F-region to the magnetosphere at a value close to the theoretical limiting flux during the daytime in all seasons. At night the flux becomes downward commencing near midnight in winter, but may remain upward throughout the night in summer. 1978-09-18T00:00:00Z https://hdl.handle.net/1721.1/97673 Millstone Hill Thomson Scatter Results for 1971 Evans, J. V.; Emery, B. A.; Holt, J. M. During 1971, the incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) was employed to measure the electron density, electron and ion temperatures, and the vertical velocity of the 0[superscript +] ions in the F-region over periods of 24 hours on 20 days. The observations spanned the height interval 200 to 900 km, approximately, and achieved a time resolution of about 30 minutes. This report presents these results, after smoothing as a set of machine-drawn contour plots. The report discusses the behavior observed in 1971 in light of that seen in previous years. A significant number of days appear to have been disturbed by large traveling ionospheric disturbances. Results for the average exospheric temperature, the mean meridional, and zonal winds for 1970and 1971 derived from these incoherent scatter measurements in a separate study by B.A. Emery are summarized here for completeness. The results appear to confirm the mean wind behavior that would be predicted by the recent Mass-Spectrometer, Incoherent-Scatter (MSIS) global model for the thermosphere and support the view that interhemispheric transport of light neutral constituents (e.g., atomic oxygen) gives rise to tie anomalous seasonal behavior of the ionosphere at midlatitudes. 1978-03-24T00:00:00Z https://hdl.handle.net/1721.1/97672 Millstone Hill Thomson Scatter Results for 1970 Evans, J. V.; Holt, J. M. During 1970, the incoherent scatter radar at Millstone Hill (42.6°N, 71.5°W) was employed to measure the electron density, electron and ion temperatures, and vertical velocity of the ions in the F-region over periods of 24 hours on an average of twice per month. The observations spanned the height interval 200 to 900 km, approximately, and achieved a time resolution of about 30 minutes. This report presents the results of these measurements in a set of contour diagrams. Commencing with the data presented in this report, a method of data reduction has been used which supersedes the older one of constructing the contour diagrams by hand. In the new method the set of points for any given parameter is matched by a two-dimensional polynomial surface in a least-squares fit. The program that carries this out is described fully in the report. By obtaining a continuous analytical description of the data with respect to height and time, machine-drawn contouring becomes possible and is now employed. The new program also provides a means of transferring the results to other users in machine-readable form. In addition, the new program yields a more repeatable smoothing of the data with respect to height and time, thereby allowing parameters that depend upon gradients (e.g., heat and particle fluxes) to be estimated more accurately. 1976-05-11T00:00:00Z https://hdl.handle.net/1721.1/97671 Millstone Hill Thomson Scatter Results for 1969 Evans, J. V. This report summarizes the results for the electron-density distribution, electron and ion temperatures, and vertical ionization fluxes in the F-region obtained during 1969 using the Millstone Hill (42.6°N, 71.5°W) Thomson (incoherent) scatter radar system. These data, for the height interval approximately 200 to 900 km, were gathered over 24-hour observing periods, roughly twice per calendar month. The time resolution to obtain results over this entire height interval was either 30 or 45 minutes, depending upon which of two operating modes was employed. The results for the diurnal variation of the electron density and temperature exhibit the characteristic summer and winter patterns discussed previously. The transition between the two takes place in April and October. Two cases of overhead auroral precipitation were observed during the year as a consequence of efforts to observe a stable red arc. Other instances of geomagnetically disturbed behavior were infrequent. Vertical fluxes of ionization were measured, and the flux escaping to the magnetosphere near midday was found to have an average value of ~5 x 10[superscript 7] el/cm[superscript 2]/sec. Near midnight, the magnetosphere appears to supply the local ionosphere with a flux of about half this amount.. 1974-07-23T00:00:00Z https://hdl.handle.net/1721.1/97670 Millstone Hill Thomson Scatter Results for 1968 Evans, J. V. This report summarizes the results for the electron density distribution, electron and ion temperatures in the F-region obtained during 1968 using the Millstone Hill (42.6°N, 71.5°W) Thomson (incoherent) scatter radar system. These data, for the height interval approximately 200 to 800 km, were gathered over 24-hour observing periods, roughly twice per calendar month. The time required to obtain a complete electron density and temperature profile over this height interval was usuaIly 30 minutes. During 1968 the apparatus employed to measure the frequency spectrum of the reflected signals vs altitude, which in turn yields the estimates of the electron and ion temperatures, was rebuilt permitting the measurements at all altitudes to be made in real time, and with greater accuracy than heretofore. In addition, the new spectrum analyzer permitted the first measurements at Millstone Hill of the vertical drift of the plasma. These results, which are difficult to condense into summary form, are not included in the report. The density and temperature results show that the separate clear patterns of summer and winter diurnal behavior, recognized at sunspot minimum, can still be discerned at sunspot maximum on all but very disturbed days. A number of disturbance patterns observed previously were again detected in 1968, albeit on fewer occasions than in 1967. Apparently, by chance, the days selected for observation in 1968 contained fewer instances of magnetic disturbance than in 1967. The average heat flux from the magnetosphere has been investigated. While there appears to be a clear dependence on solar flux (as defined by the 10.7-cm radio emission), there remains a summer-to-winter variation of 5 to 7 that cannot be easily explained. 1973-01-23T00:00:00Z https://hdl.handle.net/1721.1/97669 Millstone Hill Thomson Scatter Results for 1967 Evans, J. V. This report summarizes results for the electron density distribution and electron temperature of the F-region obtained during 1967 using the Millstone Hill (42.6“N, 71.5°W) Thomson (incoherent) scatter radar system. These data, for the height interval of approximately 200 to 800 km, were gathered over 24-hour observing periods twice per calendar month. The time required to obtain a complete electron density and temperature profile over this height interval was 30 minutes. The results show a far wider range of behavior than that encountered in previous years. This is attributed to the increase in magnetic activity as sunspot maximum is approached. On magnetically quiet days, the characteristic behavior observed previously for electron density manifests itself. Winter days exhibit a maximum at all levels near noon and a weaker maximum at the layer peak in the early morning (0200 to 0400 EST), while summer days exhibit a maximum near sunset and only a small day-to-night change in density near the layer peak. Two days exhibited a pattern of behavior, first noted in 1965, that appears characteristic of many storms. This consists of an increase in density on the afternoon of the first day of the storm followed by a marked decrease the next morning. Other days show instances of nocturnal heating and erratic behavior of the F-region electron density at night. We believe that on several occasions in 1967 the plasmapause boundary moved south of Millstone giving rise to a rapid fall in f[subscript o]F2 and to much of the irregular behavior observed at night. 1971-07-22T00:00:00Z https://hdl.handle.net/1721.1/97668 Millstone Hill Thomson Scatter Results for 1966 Evans, J. V. This report presents F-region electron densities and electron temperatures observed during the year 1966 at the Millstone Hill Radar Observatory (42.6°N, 71.5°W) by the UHF Thomson (incoherent) scatter radar. The measurements were usually made for periods of 24 hours twice per month, and covered the altitude range 150 to 750 km approximately. The time required to collect all the measurements spanning this height interval was 30 minutes, i.e., half that of previous years. The results exhibit a greater amount of random time variation than seen heretofore, partly as a result of the better time resolution achieved and partly because each day has been analyzed individually, i.e., we have discontinued the practice of computing only the monthly mean behavior. We believe, however, that the largest part of the random variation is real and results from fluctuations in the solar EUV flux, which increase in magnitude as the sunspot number rises. Also, we expect a growing incidence of fluctuations produced by large-scale traveling ionospheric disturbances as we approach sunspot maximum. Despite this variability, the characteristics “winter” and “summer” type behavior reported for Millstone in previous years is clearly recognizable. On four days in which pronounced effects due to geomagnetic storms are evident, the layer rose to great heights in the late afternoon and achieved an abnormally high density (and lower-than-normal temperature). The reverse behavior was encountered the next morning. This sequence is similar to that first seen in June 1965, and its interpretation in terms of current ideas is summarized. 1971-01-19T00:00:00Z https://hdl.handle.net/1721.1/97667 Incoherent Scatter Measurements of F-Region Density, Temperatures, and Vertical Velocity at Millstone Hill Evans, J. V.; Julian, R. F.; Reid, W. A. The Millstone Hill Thomson (incoherent) scatter radar system has been operated routinely since 1963 to perform a synoptic study of F-region electron densities, and electron and ion temperatures. This report describes system changes made in 1968 which considerably increased the accuracy of the measurements and allowed their extension to higher altitudes. These changes have also made it impossible to measure the vertical velocity of the plasma over the altitude range 450 to 900 km to an accuracy on the order of 5 to 10 m/sec, depending upon altitude and time of day. Of even greater significance, complete machine reduction of the results is now possible so that considerable savings in time and effort have been secured in analyzing the data. The new system permits all the radar data to be gathered in the digital computer in real time, thereby eliminating the need for post real-time processing of magnetic-tape recordings of the signals. Furthermore, it is now possible to transmit the data to other workers in computer-usable form. This report describes the main functions of the computer program required to analyze the measurements, and lists the times of all measurements made with the new system prior to 1 January 1970. Examples of these results are presented and discussed. 1970-02-06T00:00:00Z https://hdl.handle.net/1721.1/97666 Millstone Hill Thomson Scatter Results for 1965 Evans, J. V. This report presents F-region electron densities, and electron and ion temperatures observed during the year 1965 at the Millstone Hill Radar Observatory (42.6°N. 71.5“W) by the UHF Thomson (incoherent) scatter radar. The measurements were made over 48-hour periods that were usually scheduled to include the International Geophysical World days near the center of each month. Geomagnetic storm sudden commencements occurred during two of the observing periods, but do not appear to have given rise to marked variation of the densities or temperatures. On the other band, measurements made during the progress of a major storm (15-19 June 1965) exhibit large changes compared with the behavior observed in the following month. The remaining months were magnetically quiet, and the density and temperature behavior were similar to those observed in 1964. Millstone is a midlatitude station exhibiting a characteristic “winter” and "summer” daytime density variation. The transition between these two types occurs rapidly around equinox, without any corresponding seasonal change in the F-region thermal structure. Current ideas concerning the mechanisms responsible for this and other features of diurnal and seasonal variations arc discussed. 1969-12-08T00:00:00Z https://hdl.handle.net/1721.1/97665 Millstone Hill Thomson Scatter Results for 1964 Evans, J. V. Thomson scatter (incoherent backscatter) observations of the ionosphere were made at Millstone Hill at a wavelength of 68 cm during 1964, for 30-hour periods every two weeks. These data have been employed to derive the mean hourly F-region (200 to 700 km) electron density profile and electron and ion temperature curves in each month. The results are presented in this report, together with the derived seasonal variation of electron density (at 0600, 1200, 1800 and 2400 hours local time) and the average daytime (0900 to 1500) and nighttime (2100 to 0300) electron and ion temperature behavior. Separate measurements with a 23-cm radar permitted the temperature results reported to be extended to lower altitudes (~130 km) and, in addition, provided information concerning the ionic constituents between 130 and 230 km. Although 1964 was at sunspot minimum, the seasonal variation in f[subscript o]F2 was quite evident. It is shown that this feature is strictly associated with the peak of the layer and that densities above 400-km altitude are highest at the equinoxes. No seasonal variations of temperature are found which might be large enough to account for the phenomenon. At night the peak densities are highest in summer, and the temperatures at all altitudes highest in winter. This last effect is believed largely due to heat conducted from the protonosphere, which in winter continues to be heated by photoelectron escape from the conjugate ionosphere which remains sunlit throughout the night. 1967-11-15T00:00:00Z https://hdl.handle.net/1721.1/97664 Ionospheric Backscatter Observations at Millstone Hill Evans, J. V. Studies of the electron-density, eIectron and ion temperatures in the F-region were mode by means of ground-based radar observations at the MilIstone Hill Radar Observatory. A 70-meter parabolic antenna directed vertically and a 2.5-Mw pulse radar operating at 440 Mcps were employed for these measurements which were conducted for periods of 30 hours at approximately weekly intervals throughout 1963. Examination of the echo power as a function of height leads to a profile of electron density with height, provided the electron and ion temperatures are the same (T[subscript e] = T[subscript i]). Additional measurements of the spectra of the signals corresponding to different heights permit the ratio T[subscript e]/T[subscript i] to be determined and, where this is different from unity, the observed profile can then be corrected for the effect on the scattering introduced by the inequality in temperature. Results of observations extending over a period of one year from February 1963 to January 1964 are presented. The ratio T[subscript e]/T[subscript i] achieved a maximum value ~2.0 to 2.6 at a height of about 300 km soon after dawn, irrespective of the season. There was Iittle change in height dependence in this ratio throughout the daylight hours, and at sunset the ratio felI with a time constant of the order of an hour. At night T[subscript e]/T[subscript i] was occasionally close to unity, but more often a significant difference remained in the temperatures at all heights. Ion temperature increased with height at all times, but above 500 km this may be due in part to the presence of an unknown amount of He[superscript +] ions, which considerably affects the interpretation of the signal spectra. Electron temperatures were largely independent of height above about 300 km. Evidence is presented of ionospheric heating during magnetically disturbed conditions, but it is shown that this is only of great importance at night. 1965-01-22T00:00:00Z https://hdl.handle.net/1721.1/97662 Studies of the F-Region by the Incoherent Backscatter Method Evans, J. V. The Millstone Hill radar facility operated by M.I.T. Lincoln Laboratory has made measurements of the distribution of electrons in the F-region of the ionosphere by observing the weak incoherent backscatter signal. These measurements were first made early in 1960 and were continued throughout 1961 on a routine basis at least once a week. This report presents alI the electron density profiles measured up to the end of 1961. Results of spectral analyses of the signals made early in 1962 are also given. The distribution of electrons above the peak of the F-region has been a subject of special study. On the basis of the results obtained to date the conclusions reached are: (a) the scale height of the electron density increases with height, (b) the ion temperature is not very dependent on height, though it does show a marked diurnal variation, (c) the election-to-ion temperature ratio is 1:1 during the hours of darkness, but during the daytime it increases too peak value ~1.6:1 around noon and (d) the scattering cross section for the electrons is close to the expected value when alIowance is made for (c). 1962-07-24T00:00:00Z