https://hdl.handle.net/1721.1/164720 Tue, 07 Apr 2026 10:06:53 GMT 2026-04-07T10:06:53Z 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. Tue, 28 Mar 2017 00:00:00 GMT https://hdl.handle.net/1721.1/165054 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. Mon, 14 Sep 2015 00:00:00 GMT https://hdl.handle.net/1721.1/165053 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. Fri, 04 Sep 2015 00:00:00 GMT https://hdl.handle.net/1721.1/165052 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. Sun, 29 Mar 2015 00:00:00 GMT https://hdl.handle.net/1721.1/165051 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. Sat, 01 Sep 2018 00:00:00 GMT https://hdl.handle.net/1721.1/165050 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. Tue, 01 May 2018 00:00:00 GMT https://hdl.handle.net/1721.1/165049 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. Sun, 01 Oct 2017 00:00:00 GMT https://hdl.handle.net/1721.1/165048 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. Wed, 24 May 2017 00:00:00 GMT https://hdl.handle.net/1721.1/165047 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. Mon, 12 Dec 2016 00:00:00 GMT https://hdl.handle.net/1721.1/165046 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. Tue, 20 Aug 2024 00:00:00 GMT https://hdl.handle.net/1721.1/165045 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. Fri, 04 Nov 2022 00:00:00 GMT https://hdl.handle.net/1721.1/165044 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. Wed, 09 Feb 2022 00:00:00 GMT https://hdl.handle.net/1721.1/165043 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. Tue, 26 Oct 2021 00:00:00 GMT https://hdl.handle.net/1721.1/165018 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. Thu, 21 Nov 2019 00:00:00 GMT https://hdl.handle.net/1721.1/164885 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. Fri, 19 Jul 2024 00:00:00 GMT https://hdl.handle.net/1721.1/164884 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. Fri, 18 Oct 2024 00:00:00 GMT https://hdl.handle.net/1721.1/164864 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. Wed, 09 Dec 2020 00:00:00 GMT https://hdl.handle.net/1721.1/164721 2020-12-09T00:00:00Z