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The ngVLA Memo Series

A series of technical and scientific memos related to the ngVLA are continually being published in the ngVLA memo series. 

Memos may be submitted by anyone in the community and represent the opinions of the author(s). While many ideas expressed in the memo series are subsequently adopted into the design, publication of a memo does not constitute project concurrence with the findings. For the approved and evolving project baseline, please reference the Project Design documentation.

 
General Memos
Technical Memos (Antenna)
Technical Memos (Electronic)
Computing Memo
ngVLA-J Memos (ngVLA-Japan Memo Series)

 

General Memos

       
       
Memo Number Title Author(s) Date
1 Fast Switching Phase Calibration At 3mm at the VLA Site C. L. Carilli 06/01/15
2 Calibration Strategies for the Next Generation VLA B. Clark 07/16/15
3 Possible Configurations for the ngVLA B. Clark, W. Brisken 07/31/15
4 The Concept of a Reference Array for ngVLA F. Owen 09/03/15
5 Science Working Groups Project Overview C. L. Carilli, et al. 10/23/15
6 Science Working Group 1: The Cradle of Life A. Isella, et al. 10/23/15
7 Science Working Group 2: "Galaxy Ecosystems" : The Matter Cycle in and Around Galaxies A. K. Leroy, et al. 10/23/15
8 Science Working Group 3: Galaxy Assembly through Cosmic Time C. M. Casey, et al. 10/23/15
9 Science Working Group 4: Time Domain, Fundamental Physics, and Cosmology G. C. Bower, et al. 10/23/15
10 Considerations for a Water Vapor Radiometer System B. Clark 12/08/15
11 Imaging Capabilites: Protoplanetary Disks Comparison of ngVLA, JVLA, ALMA C. L. Carilli, L. Ricci, P. Barge, B. Clark 04/08/16
12 The Strength of the Core C. L. Carilli 10/14/16
13 Image Capabilities: High Redshift CO C. L. Carilli, Y. Shao 03/13/17
14 Short Spacing Considerations for the ngVLA D. T. Frayer 06/08/17
15 Galaxies into the Dark Ages C. L. Carilli, E.J. Murphy, A. Ferrara, P. Dayal 06/08/17
16 More on Synthesized Beams and Sensitivity C. L. Carilli 06/19/17
17 ngVLA Reference Design Development & Performance Estimates R. Selina, E. Murphy 07/18/17
18 Summary of the Science Use Case Analysis R. Selina, E. Murphy, A. Erickson 07/26/17
19 Key Science Goals for the Next Generation Very Large Array (ngVLA): Report from the ngVLA Science Advisory Council ngVLA Science Advisory Council 08/02/17
20 Next Generation Low Band Observatory: A Community Study Exploring Low Frequency Options for ngVLA G. Taylor, et al. 08/11/17
21 ngVLA Sensitivity B. Butler, W. Grammer, R. Selina, E. Murphy, C. Carilli 06/26/19
22 Sub-Nanosecond Time Accuracy and Frequency Distribution through White Rabbit Ethernet C. van Tour, J. C. J. Koelemeij 09/04/17
23 Smart Energy Cryo-Refrigerator Technology for the Next Generation Very Large Array J. Gardiner, et al. 09/01/17
24 Advanced Cryocoolers For Next Generation VLA L. R. D'Addario 09/29/17
25 Exploration of Suitable Mounts for a 15m Offset Antenna Next Generation Very Large Array NRC 15m Mount M. Fleming 10/23/17
26 ngVLA Technical Study Offset Gregorian Antenna D. Chalmers, G. Lacey, M. Islam, M. Fleming, L. Baker 10/23/17
27 Various Suitable Mounts for an 18m Antenna M. Fleming, R. Schultz, D. Enterline 10/30/17
28 Host Galaxies and Relativistic Ejecta of Compact Binary Mergers in the ngVLA Era A. Corsi, et al. 10/31/17
29 An Integrated Receiver Concept for the ngVLA M. Morgan, S. Wunduke 11/06/17
30 ngVLA Dynamic Range W. D. Cotton, J. J. Condon 11/07/17
31 Quantifying the ngVLA's Contribution to Exo-Space Weather: Results of a Community Studies Report R. A. Osten, M. K. Crosley 11/13/17
32 ngVLA Community Studies Report: Feed and Receiver Development at NRC Herzberg L. Locke, L. B. G. Knee, F. Jiang, V. Reshetov, L. A. Baker 11/14/17
 
33 Investigating the Early Evolution of Planetary Systems with ALMA and the Next Generation Very Large Array L. Ricci, S.-F. Liu, A. Isella, H. Li 1/5/18
34 A Dedicated Pulsar Timing Array Telescope (a.k.a. "Pulsar Town") Robert Selina, Paul Demorest, Wes Grammer 05/15/18
35 Deep Fields at 8GHz C. L. Carilli, G. C. Jones, P. Sims 2/16/18
36 High-Power, High-Speed Photodiodes Joe C. Campbell 3/5/18
37 Intermediate-Mass Black Holes in Globular Cluster Systems J. M. Wrobel, J. C. A. Miller-Jones, K. E. Nyland, T. J. Maccarone 3/9/18
38 Subarray Processing for Projection-Based RFI Mitigation in Radio Astronomical Interferometers M. C. Burnett, B. D. Jeffs, R. A. Black, K. F. Warnick 3/12/18
39 Thoughts on Transient Discovery Vikram Ravi 3/15/18
40 Revolutionizing Our Understanding of AGN Feedback and its Importance to Galaxy Evolution in the Era of the Next Generation Very Large Array K. Nyland, et al.  3/15/18
41 Initial Imaging Tests of the Spiral Configuration C. L. Carilli, A. Erickson 3/21/18
42 Pulsar Timing Array Requirements for the ngVLA S. Chatterjee, NANOGrav Collaboration 04/02/18
43 The ngVLA Short Baseline Array  B. S. Mason, R. Selina, A. Erickson, E. Murphy 04/18/18
44 Confusion Limited Surveys with the ngVLA Spiral W. D. Cotton, J. J. Condon 04/13/18
45 Polarization Calibration with Linearly Polarized Feeds Barry Clark 04/19/18
46 Ionized Gas in Globular Cluster Systems J. M. Wrobel, K. E. Johnson 05/01/18
47 Resolution and Sensitivity of ngVLA-RevB C. L. Carilli 05/23/18
48 ngVLA Radio Frequency Interference Forecast A. Erickson 07/01/18
49 Snapshot UV Coverage of the ngVLA: An Alternate Configuration R. Craig Walker 07/05/18
50 Imaging Cold Gas to 1 kpc Scales in High-Redshift Galaxies with the ngVLA Caitlin M. Casey, Desika Narayanan, Chris Carilli, Jaclyn Champagne, Chao-Ling Hung, Romeel Davé, Roberto Decarli, Eric J. Murphy, Gergo Popping, Dominik Riechers, Rachel S. Somerville, Fabian Walter 08/24/18
51 Taking a Census of Supermassive Binary Black Holes Karishma Bansal & Greg Taylor 10/05/18
52 The 2018 Eruption of Nova V392 Per: A Case Study of the Need for ngVLA Justin D. Linford, Joe S. Bright, Laura Chomiuk, Alexander J. van der Horst, & Rob P. Fender 11/20/18
53 Revealing the Galactic Population of Black Holes with the ngVLA Thomas J. Maccarone, Laura Chomiuk, Jay Strader, James Miller-Jones, Greg Sivakoff 11/26/18
54 Short Spacing Issues for Mapping Extended Emission: Milky Way Case Study J. A. Turner, P. Teuben, D. A. Dale 01/09/19
55 Taperability Study for the ngVLA and Performance Estimates Viviana Rosero 01/31/19
56 Radio Frequency Interference Cancellation, Appraisal, Detection, and Correction M. J. Lambert, B. Jeffs 02/01/19
57 Imaging the Distribution of Solids in Planet-Forming Disks Undergoing Hydrodynamical Instabilities with the Next Generation Very Large Array L. Ricci, M. Flock, D. Blanco, W. Lyra 02/05/19
58 μas Astrometry with the ngVLA Carl Melis 03/01/19
59 QAC: Quick Array Combinations with CASA P. Teuben 03/25/19
60 Image Dynamic Range Limits Arising from Visibility Errors C. A. Hales 02/21/19
61 Temporal and Spatial Tropospheric Phase Fluctuations at the VLA (and Beyond) and Implications for Phase Calibration C. A. Hales 03/07/19
62 Reserved    
63 Reserved    
64 High Dynamic Range Imaging C. L. Carilli 04/29/19
65 Sculpting of the Synthesized Beam and Image Fidelity Study of KSG 1: Imaging of Protoplanetary Disks V. Rosero 05/17/19
66 Exploring Regularized Maximum Likelihood Reconstruction for Stellar Imaging with the ngVLA   (Supplemental Material)  K. Akiyama & L. D. Matthews 09/30/19
67 Demonstration & Analysis of ngVLA core + Short Baseline Array Extended Structure Imaging (V2) B. Mason 1/08/21
68 Imaging the Dusty Substructures Due to Terrestrial Planets in Planet-forming Disks with the Next Generation Very Large Array S. K. Harter, L. Ricci, S. Zhang, Z. Zhu 11/12/19
69 Remote Service Station Study K. Renda, M. Luce, A. Erickson 12/06/19
70 RFI Mitigation for the ngVLA : A Cost-Benefit Analysis Urvashi Rau, Rob Selina, Alan Erickson 12/10/19
71 RFI Mitigation in the ngVLA System Architecture Rob Selina, Urvashi Rau, Rafael Hiriart, Alan Erickson 02/06/20
72 A Study of ngVLA Subarray Efficiency: Plains + Fractions of the Core V. Rosero 01/15/20
73 Preliminary ngVLA Observing Band Availability Estimate Bryan J. Butler 01/31/20
74 Channel Weights for the VLA CWVRs Bryan J. Butler 04/20/20
75 Image Corruption From Antenna Pointing Errors: Simulation Results (and Useful Teaching Tool) Christopher A. Hales 04/24/20
76 Subarray Selection for the Reference Observing Program Viviana Rosero 06/01/20
77 Fast Transients with the ngVLA C.L. Carilli, K. P. Mooley, E. Jiménez-Andrade, E. Murphy 06/09/20
78 High Resolution, Wide Field, Narrow Band, Snapshot Imaging C. L. Carilli, E. Murphy, V. Rosero, K. Mooley, E. Jiménez-Andrade, K. Golap, B. Butler 06/15/20
79 Synthesis of Optimal Estimators for Water Vapor Radiometry N. Towne 06/17/20
80 Quasar Wind SZ imaging with the ngVLA C. L. Carilli, M. Lacy. B. Mason, A. Chakraborty, S. Chatterjee 07/08/20
81 VLA Limits on Intermediate-Mass Black Holes in 19 Massive Globular Clusters J. M. Wrobel, K. E. Nyland 07/23/20
82 Configuration: Reference Design RevC.01 Description C. Carilli, J. Carilli, A. Erickson, E. Murphy, B. Mason, V. Rosero, B. Butler 08/28/20
83 Imaging Cold Gas in High-Redshift Galaxies with the ngVLA Desika Narayanan, Eric F. Jiménez-Andrade, Eric Murphy, Qi Li, Viviana Rosero 09/17/20
84 The NGVLA Long Baseline Array: Configuration Suggestions R. Craig Walker 10/04/20
85 Comparison of Alternative Configurations for the ngVLA Plains Subarray  Addendum V. Rosero, J. Carilli, C. Carilli, B. Mason 10/20/20
86 Imaging Evaluation of Two Mid Configurations C. L. Carilli, R. C. Walker, B. S. Mason, J. P. Carilli 02/19/21
87 Accessing Intermediate-Mass Black Holes in 728 Globular Star Clusters in NGC4472  J. M. Wrobel, T. J. Maccarone, J. C. A. Miller-Jones, and K. E. Nyland 05/04/21
88 Testing Photoevaporation and MHD Disk Wind Models Through Future High-Angular Resolution Radio Observations: the Case of TW Hydrae Luca Ricci, Sarah K. Harter, Barbara 04/09/21
89 Image Fidelity Study of KSG 3 (NGA8): Imaging Molecular Gas in Nearby Galaxies Addendum   Viviana Rosero, Eric F. Jiménez-Andrade 06/24/21
90 Astrometric Constraints on a Massive Black Hole Binary in NGC4472 J. M. Wrobel, T. J. W. Lazio 06/15/21
91 Status of the VLA CWVRs Bryan J. Butler 07/19/21
92 Configuration: Reference Design Rev D Description C. Carilli, B. Mason, V. Rosero, B. Butler, J. Carilli, E. Murphy, R.C. Walker 10/28/21
93 Reserved    
94 Reserved    
95 Evaluation of the Revision D array configuration for stellar imaging Catherine Petretti, Kazunori Akiyama, and Lynn D. Matthews 10/04/21
96 ngVLA Antenna Noise Temperature Calculation Bryan J. Butler, Wes Grammer, Robert Lehmensiek 10/18/21
97 A Suggested Final Configuration for the Very Large Array J. M. Wrobel, R. C. Walker 05/13/22
98 Candidate Phase Calibrators at 93GHz in the ngVLA Sky J. M. Wrobel and A. Y. Q. Ho 08/08/22
99 Search for Extraterrestrial Intelligence with the ngVLA C. Ng, L. Rizk, C. Mannion, E. F. Keane 08/18/22
100  Configuration: Rev E Staggered Spiral Tests C. Carilli, V. Rosero, J. Carilli, B. Mason 09/13/22
101 Mapping the Gas Density and Kinematic Structures due to Embedded Protoplanets in Young Disks with the Next Generation Very Large Array L. Ricci, B. Burrill, I. Rabago, Z. Zhu 09/27/22
102 Enhanced Central Condensation Options for the Configuration of ngVLA MID  R. Craig Walker 10/04/22
103 Spectroscopy of High Redshift Galaxies with the ngVLA C.L. Carilli, Marcel Neeleman 10/24/22
104 Rev E MID Tests: Sensitivity at 7mas Resolution C.L. Carilli 11/10/22
105 Suggested Changes to ngVLA LONG R. Craig Walker 11/21/22
106 ngVLA Imaging Science Performance Reference Document Viviana Rosero, Chris Carilli 11/28/22
107 The Relationship Between Image Dynamic Range and Antenna-based Gain Errors T.K. Sridharan, Kumar Golap, Sanjay Bhatnagar & Steve Myers 01/03/23
108 Feasibility of Self-cal for ngVLA Dynamic Range Requirements T. K. Sridharan & Sanjay Bhatnagar 01/03/23
109 Updated RFI Impact Estimates & Influence on the System Design R. Selina, U. Rau, C. De Pree 04/24/23
110 Implications for the ngVLA from VLBA Phase Stability at 43 GHz R. Craig Walker 04/25/23
111 First characterization of MID locations in Northern Mexico Alfonso Trejo, Leslie Watson 04/11/23
112 High Dynamic Range Imaging at 8 GHz at 1mas Resolution C.L. Carilli 04/21/23
113 ngVLA Dynamic Range Requirements E.J. Murphy 06/05/23
114 High Dynamic Range Imaging at 8 GHz with Spiral and Core, Including Phase Errors C. L. Carilli 06/12/23
115 Environmental Monitoring Requirements for the ngVLA T. K. Sridharan, Jeff Mangum & Bryan Butler 06/26/23
116 Imaging the Radio Recombination Lines from M15's Planetary Nebula K648 J. M. Wrobel, D. S. Balser, J. C. A. Miller-Jones 09/19/23
117 The Portable Weather Station: 2022 Site Testing Justin Linford & Jon Cooper 09/05/23
118 Imaging the ring and jet in M87 at 85 GHz with the ngEHT and ngEHT+ngVLA C.L. Carilli, R.C. Walker, E. Murphy, B. Mason 09/22/23
119 Detrimental Emission Levels for Orbital RFI R. Selina, C. De Pree 10/04/23
120 Multiple Absoprtion Sightlines Through a Dark Matter Halo J.M. Wrobel and F. Walter 12/05/23
121 Subarray Study for the Envelope Observing Program Viviana Rosero & Brian Mason 04/10/24
122 Characterization of the synthesized beam with and without MID antennas in Mexico Alfonso Trejo-Cruz, Roberto Galván-Madrid, Carlos Carrasco-González, Eric F. Jiménez-Andrade, Stan Kurtz, Jesús M. Jáquez-Domínguez, Alice Pasetto, Luis A.  07/02/24
123 Candidate Phase Calibrators at 93GHz in the ngVLA Sky: Developments Since 2022 J. M. Wrobel, A. Y. Q. Ho, and D. W. Pesce 06/03/24
124 Analysis of ngVLA Rev E Mid Sites Using GIS C. Price 06/25/24
125 Key Science Goals For The Next Generation Very Large Array (NGVLA): Update From The NGVLA Science Advisory Council (2024) ngVLA Science Advisory Council 08/23/24
126 VLA – ngVLA transition: Comparison of two representative fixed-mixed scale configurations to the current VLA C. L. Carilli 08/17/24
127 A Comparison of the Imaging Capabilities of RevF and RevE ngVLA Configurations for Protoplanetary Disk Studies A. A. Papazyan, L. Ricci 10/31/24

Technical Memos (Antenna)

Memo Number Title Author(s) Date
1 System-Level Cost Comparison of Offset and Symmetric Optics R. Selina 04/26/19
2 System-Level Evaluation of Aperture Size R. Selina 05/06/19
3 Antenna Optical Design Alternatives R. Selina, W. Grammer, D. Urbain, S. Sturgis, J. Allison 10/01/19
4 Performance of Dual-Offset Gregorian Antennas with Varying Subreflector Angles S. Srikanth 06/18/19
5 Measurements of the ngVLA W-Band Feed Horns L. Locke, S. Srikanth, C. Beaudet 07/10/19
6 Efficiency Loss Due to Feed Positioning Errors on the ngVLA Reference Design Antenna S. Srikanth 04/07/20
7 Axially Corrugated Feed Horns as Radiators for the 1.2 to 12.3 GHz Frequency Range on the ngVLA Reference Design Antenna S. Srikanth 06/16/20
8 Efficiency Loss and Pointing Offsets due to Feed Offsets on the ngVLA S. Srikanth 07/01/20
9 Practical Limits to Axis Offsets R. Selina 09/03/20
10 Beam Pointing and Efficiency as a Function of Translations and Rotations of Optical Elements on the ngVLA Antenna S. Srikanth 09/04/20
11 SBA Antenna Pointing Specification for the Conceptual Design Brian S. Mason 07/30/21
12 Verification Testing for the ngVLA 18m Prototype Antenna Jeff Mangum 01/11/22
13 NGVLA Antenna On-the-Fly Mapping Use Cases Brian Mason & Jeff Mangum 02/04/22
14 Long Baseline Antenna Prototype Test Site Selection R. Selena 02/28/24
15 Long Baseline Antenna Prototype: Antenna Qualification Electronics Concept R. Selina, W. Grammer, J. Jackson, J. Mangum, M. Morgan, J. Muehlberg, M. Schiller, B. Shillue 06/11/24
16 Long Baseline Antenna Prototype: DBE Concept Matthew Schiller 06/27/24
17 ngVLA Pointing System Recommendation Jeff Mangum 10/22/24

Technical Memos (Electronic)

Memo Number Title Author(s) Date
1 Downconversion and Digitization Methodology for the ngVLA M. Morgan 01/06/20
2 ngVLA Solar Power Trade Study Kevin Baker 06/29/20
3 Advanced Stirling Pulse Tube Cryocooler and Variable Speed Gifford McMahon Cryocooler Trade Study  Denis Urbain 08/28/20
4 Trident 2.0 Concept: A Minimum Delta Update to the Central Signal Processor Reference Design Omar Yeste Ojeda 01/17/20
5 Trident 2.1 Concept: Updates to the CSP Reference Omar Yeste Ojeda 09/11/20
6 A First Order Reliability Model for a VLA Antenna: Mining MainSaver and JIRA for VLA Reliability Data M. Luce, A. Erickson, K. Swift, J. Ogle 10/21/20
7 EVLA Subsystem MTBF Analysis K. Swift, M. Luce, J. Gregg, A. Erickson, J. Ogle 11/09/20
8 Headroom, Dynamic Range, and Quantization Considerations R. Selina, O. Yeste Ojeda 01/20/21
9 Design Considerations for Band 1 Receiver of ngVLA Bogdan Sadowski 03/30/21
10 A SCREAM-Compatible ngVLA Cross-Correlation Engine: Key Requirements Review and Option Trade-Off Study N. Denman 09/03/21
11 A SCREAM-Compatible ngVLA Pulsar Engine: Key Requirements Review and Option Trade-Off Study N. Denman 09/03/21
12 Thermoacoustic Stirling Cryocooler and Variable Speed Gifford McMahon Cryocooler Trade Study No. 2 Denis Urbain 10/22/21
13 Reserved    
14 The MSIP Qualification Electronics Design and Hardware Robert Long 06/06/22
15 Timing Requirements & Considerations R. Selina, B. Shillue, O. Yeste Ojeda, M. Schiller 07/18/23
16 Trade Study: CSP Internal Data Interchange Format Nolan Denman 08/30/23
17 Investigation of High Temperature Superconductor (HTS) Directional Couplers for ngVLA Receiver Front-End Applications     B. DuVerneay, A. Navarrini, W. Grammer 12/06/23
18  A Turnstile Orthomode Transducer (OMT) Design for the ngVLA Band 3 Receiver B. DuVerneay, W. Grammer 08/27/24

Computing Memos

Memo
Number		 Title Author(s) Date
1 Efficient Software Testing and Deployment for the ngVLA P. Brandt 03/27/20
2 Computing M&C Protocol Trade Study P. Brandt, R. Hiriart, R. Amestica 08/04/21
3 Software Requirements for RFI Management R. Amestica, R. Hiriart, P. Brandt 08/04/21
4 Size-of-Computing Estimates for ngVLA Synthesis Imaging S. Bhatnagar, R. Hiriart, M. Pokorny 08/10/21
5 High Performance Gridding M. Pokorny 08/31/21
6 Designing an ngVLA Dynamic Scheduler P. Brandt 09/13/21
7 Baseline HPG Runtime Performance for Imaging S. Bhatnagar, F. Madsen and J. Robnett 05/09/22
8 Time Averaging Limits and Baseline Dependent Averaging for the ngVLA J.-W. Steeb, Z. Gillis 05/03/23
9 ngVLA Multi-subarray Scheduling Algorithm Rafael Hiriart 01/06/24
10 Oscilloscope Mode Concept P. Brandt, M. Schiller 01/17/24
11 ngVLA Data Rates and Computational Loads (Update) Rafael Hiriart 08/30/24
12 System Considerations for ngVLA Data Processing, Transport and Storage  Rafael Hiriart 09/04/24

 

The Next Generation Very Large Array (ngVLA) is a development project of the National Radio Astronomy Observatory (NRAO). NRAO is a facility of the National Science Foundation (NSF) operated under cooperative agreement by Associated Universities, Inc. This material is based upon work supported by the NSF under Grant No. AST-1519126. Any opinions, findings, and conclusions or recommendations expressed in the materials are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.