Overview: This is the memo series for the Long Wavelength Array (LWA) project. This consolidates and supercedes earlier memo series by NRL and at Virginia Tech.
Maintainer: S.W. Ellingson
URL: http://www.phys.unm.edu/~lwa/memos
Last 5 Updates:
2008 Jun 28: Added LWA Memo 139 (Kogan/Cohen/Polisensky, Elliptical Station)
2008 Jun 15: Added LWA Memo 138 (Ellingson, Single Stand Calibration)
2008 Jun 12: Added LWA Memo 137 (Kerkhoff, S Parameter ... Antenna Measurements)
2008 Jun 01: Added LWA Memo 136 (Ellingson, Cable Dispersion)
2008 May 22: Added LWA Memo 135 (Hicks/Erickson, Bias-Tee)
Table of Contents:
Please send submissions to the maintainer.
Indexed in reverse chronological order, by date of entry into memo series.
Please cite as: Author(s), Title of Memo, Long Wavelength Array Memo (number), date UNLESS more properly cited in another form (e.g., astro-ph, published paper).
[139] L. Kogan, A. Cohen, and E. Polisensky, Elliptical LWA Station Configurations Optimized to Minimize Side Lobes, June 24, 2008. Additional material: lwa0139.zip.
[138] S. Ellingson, Single-Stand Polarimetric Response and Calibration, June 15, 2008.
[137] A. Kerkhoff, S Parameter Extraction Approach to the Reduction of Dipole Antenna Measurements, Feb 14, 2008.
[136] S. Ellingson, Dispersion in Coaxial Cables, Jun 01, 2008.
[135] B. Hicks and B. Erickson, Bias-T Design Considerations for the LWA, May 21, 2008.
[134] K. Lee and S. Ellingson, Terrestrial Propagation at LWA Frequencies, May 2, 2008.
[133] P. Crane, Radio-Frequency Interference from Digital Television, Apr 29, 2008.
[132] T. Clarke, Long Wavelength Array: Day in the Life Operation Model, Ver. 1.0, Apr 25, 2008.
[131] G. Taylor and P. Ray, LWA Data Communications - The Fiber Option, Apr 25, 2008.
[130] J. Craig, M. Harun, and S. Ellingson, On-the-Air Demonstration of a Prototype LWA Analog Signal Path, Apr 12, 2008.
[129] S. Ellingson, Interaction Between an Antenna and a Fence, Mar 24, 2008.
[128] A. Cohen and N. Paravastu, Probing the Ionosphere with the LWA by Rapid Cycling of Celestial Radio Emitters, Mar 12, 2008.
[127] M. Harun and S. Ellingson, Design and Development of a Prototype ADC for LWA, Mar 4, 2008.
[126] M. Kavic, J. Simonetti, S. Cutchin, S. Ellingson, C. Patterson, Transient Pulses from Exploding Primordial Black Holes as a Signature of an Extra Dimension, astro-ph/0801.4023, Jan 25, 2008.
[125] R. Osten, Flaring Stars and the Long Wavelength Array, Feb 14, 2008.
[124] H. Schmitt, B. Hicks, K. Stewart, T. Clarke, Report from LWDA Site Field Trips Dates: 11/26-30/07; 01/17/08, entered Feb 9, 2008.
[123] D. Chen, Definitions of System Requirement, Preliminary Design, and Critical Design Reviews, Feb 5, 2002. Not a typo! This is an old but useful NRL memo.
[122] J. York, LWA DRX C Language Simulation Report, v0.1, Feb 1, 2008.
[121]
S. Ellingson,
LWA Analog Signal Path Planning, Ver. 2,
Feb 3, 2008.
Earlier version: S. Ellingson,
LWA Analog Signal Path Planning,
Jan 23, 2008.
[120] B. Hicks and N. Paravastu, The Rapid Test Array Balun (G250R), Dec 12, 2007.
[119] S. Ellingson, Long Wavelength Array Station Architecture Ver. 1.0, Nov 19, 2007. Note: This is the version approved at SRR.
[118] C. Janes, The Long Wavelength Array System Technical Requirements Ver. ``Draft #9'', Nov 19, 2007. Note: This is the version approved at SRR.
[117] T.E. Clarke, Scientific Requirements for the Long Wavelength Array Ver. 2.3, Nov 19, 2007. Note: This is the version approved at SRR.
[116] M. Harun and S. Ellingson, Additional Design Information on the AD9230-250 and AD9211-200 ADC Evaluation Boards, December 28, 2007.
[115] S. Ellingson, Dispersion by Antennas, December 11, 2007.
[114] J. York, LWA DRX High-Level Design - v0.2, December, 2007.
[113] A. Cohen and G. Taylor, Array Configuration for the Long Wavelength Intermediate Array (LWIA): Choosing the First Four Station Sites, December 4, 2007.
[112] S. Ellingson, M. Harun, K. Lee, Evaluation of the AD9230 and AD9211 Analog-to-Digital Converters, December 3, 2007.
[111] E. Polisensky, LFmap: A Low Frequency Sky Map Generating Program, September 7, 2007.
[110] G. Taylor, LWA Data Communications - The Sneakernet Option, November 30, 2007.
[109] S.W. Ellingson, Transient Buffer - Wideband (TBW) Preliminary Design, November 11, 2007.
[108] S.W. Ellingson, BFU & DP1 Preliminary Design, November 4, 2007.
[107] S.W. Ellingson, LWA Beamforming Design Concept, October 30, 2007.
[106] S.W. Ellingson, Polarization Processing for LWA Stations, October 29, 2007.
[105] T. Clarke, W. Lane, J. Lazio, and D.L. Wood, LWDA FITS-IDI File Format Version 2.0, October 4, 2007.
[104] B.A. Jacoby, W.M. Lane, and T.J.W. Lazio, Simulated LWA-1 Pulsar Observations, September 27, 2007. Additional material: lwpsr.tar.gz.
[103] A. Kerkhoff, The Calculation of Mutual Coupling Between Two Antennas and its Application to the Reduction of Mutual Coupling Effects in a Pseudo-Random Phased Array, August 23, 2007.
[102] A. Kerkhoff, Comparison of Dipole Antenna Designs for the LWA, August 25, 2007.
[101] S. Ellingson, ADC Sample Rate and Preliminary Design for a Full-RF ADC Post-Processor, September 11, 2007.
[100] J. York, V. Sitaram, L. Shuhatovich, LWA ADC Candidate Survey, September 6, 2007.
[99]
J. Dickel, P. Crane, and A. Cohen,
More Sites for the LWA: South Circle,
August 24, 2007 (received 22 Oct 07).
Earlier version:
J. Dickel, P. Crane, and A. Cohen,
More Sites for the LWA: South Circle,
Sep 3, 2007.
[98] S. Ellingson, ADC Selection, August 31, 2007.
[97] G. Taylor, A. Cohen, P. Crane, J. Dickel, and W. Lucero, More Sites for the LWA: Sevilleta, Pie Town, Horse Springs, and Parts West, August 7, 2007.
[96] A. Kerkhoff, Comparison of Simulated and Measured Drift Scans for Broadband Dipole Antennas at Long Wavelength Array (LWA) Frequencies, July 23, 2007.
[95] J. York et al., LWDA Ground Screen Performance Report, July 23, 2007.
[94]
S. Ellingson,
System Parameters Affecting LWA Calibration (Memo 52 Redux),
Sep 20, 2007.
Earlier version:
S. Ellingson,
System Parameters Affecting LWA Calibration (Memo 52 Redux),
July 20, 2007.
[93] J. York et al., The LWDA Array: An Overview of the Design, Layout and Initial Results, April 26, 2007.
[92] N. Kassim et al., May 2007 LWDA Site Visit: Development of Outrigger Interferometer, Ground Screen Measurements, & other activities, July 11, 2007.
[91] N. Kassim, B. Erickson, and P. Ray, Proposal for a Rapid Test Array (RTA), June 26, 2007.
[90] N. Paravastu et al., Impedance Measurements of the Big Blade and Fork Antennas on Ground Screens at the LWDA Site, June 5, 2007.
[89] M. Harun and S. Ellingson, Revision of the Bandpass Filter for the LWA Analog Receiver, May 30, 2007.
[88] N. Paravastu, B. Hicks, P. Ray, and W. Erickson, A New Candidate Active Antenna Design for the Long Wavelength Array, May 10, 2007.
[87] B. Hicks, N. Paravastu, P. Ray, and B. Erickson, A Comparison of Two Power Combining Elements for LWA Active-Baluns - 180 degree Hybrid versus Wideband Transformer, May 9, 2007. Note (Jun 9, 2007): Pending revision to clarify results. Contact author(s) for details.
[86] B. Hicks, N. Paravastu, and P. Ray, Power Distribution Options for LWA Active-Antennas, April 19, 2007.
[85] K. Lee and S. Ellingson, Coherent Subtraction of Narrowband Radio Frequency Interference, May 4, 2007.
[84] R. Duffin and P.S. Ray, Radio Frequency Interference Analysis of Spectra from the Big Blade Antenna at the LWDA Site, March 23, 2007.
[83] K. Stewart, Electromagnetic Performance of a Wire Grid Ground Screen, February 12, 2007.
[82] M. Harun and S. Ellingson, A Prototype Analog Receiver for LWA, March 28, 2007.
[81] N. Paravastu, B. Hicks, R. Bradley, and C. Parashare, Development and Measurement of a Second Generation Balun Candidate for the LWA, January 25, 2007.
[80] A. Cohen, T. Clarke, J. Lazio, Early Science from the LWA Phase II: A Target List, February 12, 2007. The referenced source list (Table 2) is available in PDF and ASCII form.
[79] G. Curtis, B. Hicks, N. Paravastu, A. Kerkhoff, Failure Report for Baseline Active-Baluns Used for the LWDA, January 9, 2007.
[78] D.G. Finley, Receive Performance of LWA Big Blade Prototype Antenna Below 20 MHz, January 26, 2007.
[77] Bill Erickson, HII Absorption, November 10, 2006.
[76] T. Jaeger and R. Mutel, Description of the University of Iowa Portable RFI Monitor and Preliminary Results from the LWDA and TP Sites, Not Dated.
[75] S. Ellingson, A Design Study Comparing LWA Station Arrays Consisting of Thin Inverted-V Dipoles, January 28, 2007. Note (Jun 9, 2007): Pending revision to correct results. Contact author(s) for details.
[74]
B. Hicks et al.,
Specmaster: A Simple Spectrum Monitoring Tool,
January 27, 2007.
Earlier version:
B. Hicks et al.,
Specmaster: A Simple Spectrum Monitoring Tool,
Not Dated.
[73] S. Ellingson, Effective Aperture of a Large Pseudorandom Low-Frequency Dipole Array, 2007 IEEE Int'l Ant. & Prop. Symp., Honolulu, HI, Submitted Jan 13, 2007, Accepted.
[72]
Lee J Rickard, G. Taylor, S. Ellingson, and N. Kassim,
The Long Wavelength Array (LWA) Program Charter, Ver. 2,
Jan 8, 2008.
Earlier version: Lee J Rickard, G. Taylor, S. Ellingson, and N. Kassim,
The Long Wavelength Array (LWA) Program Charter,
December 27, 2006.
[71] B. Hicks, N. Paravastu, R. Bradley, and C. Parashare, A Low Noise, High Linearity Lossless Feedback Amplifier for LWA Applications, December 12, 2006.
[70] N. Kassim, T. Clarke, and W. Lane, LWA"1+" Scientific Requirements, December 13, 2006.
[69] D. Munton et al., LWDA Power Budget, January 5, 2007.
[68] P.S. Ray, First Light for the Long Wavelength Demonstrator Array (LWDA), January 4, 2007.
[67] S. Ellingson, Collecting Area of Planar Arrays of Thin Straight Dipoles, December 31, 2006.
[66] Lee J Rickard, Brief Introduction to Earned Value Management (EVM), December 25, 2006.
[65]
S. Ellingson,
Use of NEC-2 to Calculate Collecting Area,
December 27, 2006.
Earlier version:
S. Ellingson,
Use of NEC-2 to Calculate Collecting Area,
December 25, 2006.
[64] A. Kerkhoff, Multi-Objective Genetic Algorithm Optimization of Antennas for use in LWA, November 11, 2006.
[63] M. Harun and S.W. Ellingson, Practical Considerations in the Design of a Bandpass Filter for the LWA Analog Receiver, November 14, 2006.
[62] G. Taylor, P. Crane, F. Owen, J. Dickel, and W. Lucero, A First Look at Sites for the LWA, November 13, 2006.
[61] C.R. Anderson and S.W. Ellingson, The Analog Devices AD6636 Digital Downconverter as a Candidate LWA Receiver Component, November 9, 2006.
[60]
S. Ellingson, J. Simonetti, and C. Patterson,
Design and Evaluation of an Active Antenna for a 29-47 MHz Radio Telescope Array,
IEEE Trans. Ant. and Prop., Vol. 55, No. 3, March 2007, pp 826-831.
Earlier version:
Nov 1, 2006.
[59] P.C. Crane, Report on the CORF Meeting, 16-17 October 2006, October 20, 2006.
[58] Bill Erickson, Sky Noise Drift Scans and Sky Noise Dominance, October 8, 2006.
[57] P.C. Crane et al., Optical Communications for the Long Wavelength Array, September 30, 2006.
[56] G. Taylor et al., LWA Overview, September 22, 2006.
[55]
A. Cohen,
A Potential Array Configuration for the LWA,
September 29, 2006.
Earlier version: A. Cohen,
A Potential Station Configuration for the LWA,
September 18, 2006.
[54] Y. Pihlstrom, LWA Equipment RF Emissions: Spectrum Analyzers and Laptops, August 27, 2006.
[53] B. Erickson, H. Schmitt, E. Polisensky, Report on Mutual Coupling and Impedance Measurements on Large Blade Dipoles, August 28, 2006.
[52] A. Cohen, Estimated Collecting Area Needed for LWA Calibration, August 30, 2006.
[51] Y. Pihlstrom, D. Mertely, and E. Aguilera, LWDA Shelter Shielding Factor, August 17, 2006.
[50] Bill Erickson, Pyramid Supports for Large Blade Dipoles, August 3, 2005.
[49] N. Kassim, W. Lane, and T. Clarke, LWA Science Requirements Document V1.0: Guidelines for Scientific and Technical Requirements, August 29, 2005.
[48] W. Gerstle, LWA Civil Infrastructure Station Development Cost Estimate, August 15, 2006.
[47] Y. Pihlstrom, Maximum Allowed Emission Levels for the LWDA Electronics, November 12, 2005.
[46] S. Ellingson, In Situ Evaluation of the ETA Analog Signal Path, August 11, 2006.
[45] S. Ellingson, A ``Pile of Parts'' Cost Model for LWA Stations, August 11, 2006. Here is the referenced spreadsheet: LWA_CM_SE060811.xls (MS-Excel format).
[44] A. Kerkhoff, Status of LWDA Electronics RF Emissions Measurements, Part II, July 7, 2006.
[43] A. Kerkhoff, Status of LWDA Electronics RF Emissions Measurements, May 16, 2006.
[42] P.S. Ray et al., LWDA Site Trip Report, August 10, 2006. Documents the July 19-24, 2006 expedition.
[41]
P.S. Ray et al.,
LWDA Network Connection Implementation,
February 23, 2006.
Earlier version: P.S. Ray et al.,
LWDA Network Connection Implementation,
October 26, 2006.
Earlier version: P.S. Ray et al.,
LWDA Network Connection Implementation,
August 8, 2006.
[40] P.S. Ray, K.P. Stewart, B.C. Hicks and E.J. Polisensky, Specifications of the GASE Antennas, June 14, 2006.
[39] J. Copeland, A. Kerkhoff, C. Slack, and J. York, Report on Installation Activities at the LWDA Site, June 30, 2006 (rcvd.).
[38] A. Kerkhoff, J. York, and D. Munton, Galactic Background Measurements with the LWDA Receive Chain, May 25, 2006.
[37] N. Paravastu and B. Hicks, Sky Noise Measurements with the LWDA Small Blade Antenna at the LWDA Site, March 2006.
[36] W.C. Erickson, Tests on Large Blade Dipoles, May 22, 2006.
[35] P.S. Ray, S. Ellingson, R. Fisher, N.E. Kassim, L.J. Rickard, T. Clarke, A Strawman Design for the Long Wavelength Array Stations, DRAFT Ver. 0.1, April 11, 2006.
[34] P.S. Ray, S. Ellingson, R. Fisher, N.E. Kassim, L.J. Rickard, T. Clarke, LWA Strawman Design v.0.2, April 11, 2006.
[33] S.W. Ellingson, Preliminary Analysis of the Effects of Front End Non-Linearity on LWA/LWDA Spectroscopy, May 16, 2005.
[32] S.W. Ellingson and A. Kerkhoff, "Comparison of Two Candidate Elements for a 30-90 MHz Radio Telescope Array", 2005 IEEE Int'l Ant. and Prop. Symp., Washington, DC, July 2005 (1A: 590-3). NOTE: This copy includes corrections to errors appearing in original conference paper.
[31] S.W. Ellingson and T.C. Kramer, "Sensitivity and Bandwidth of Low-Gain Active Antennas Below 100 MHz", 2005 IEEE Int'l Ant. and Prop. Symp., Washington, DC, July 2005 (3A: 561-4).
[30] S.W. Ellingson, Analysis of a Low-Gain Antenna & Front End for Low Frequency Radio Astronomy, November 9, 2004.
[29] S.W. Ellingson, Cable Cost for LWA Stations, September 19, 2004.
[28] S.W. Ellingson, " Designing a Sky-Noise-Limited Receiver for the LWA" (presentation), Science with Wavelengths on Human Scales: A Celebration of the 74th Birthday of Bill Erickson and Low Frequency Radio Science, Santa Fe, NM, Sep 2004.
[27] S.W. Ellingson, " Receivers for Low-Frequency Radio Astronomy," From Clark Lake to the Long Wavelength Array: Bill Erickson's Radio Science (N.E. Kassim, et al. eds.), ASP Conference Series, Vol. 345, p. 321, 2005.
[26] Bill Erickson, Thoughts on the Origin of Pulsed RFI, 10/05
[25] N. Paravastu, W. Erickson, Y. Pihlstrom, N. Kassim and B. Hicks, Testing a Prototype Blade Antenna at the LWDA Site, 09/05 (Also: Previous Version)
[24] E. Polisensky, Which 128 Elements for LWDA Phase 1?, 09/05
[23] Bill Erickson, Integration Times vs. Sky Noise Dominance, 08/05
[22] S.W. Ellingson, "Antennas for the Next Generation of Low Frequency Radio Telescopes" IEEE Trans. Ant. and Prop., Vol. 53, No. 8, August 2005, pp. 2480-9.
[21] L. Kogan and A. Cohen, Optimization of the LWA Antenna Station Configuration Minimizing Side Lobes, 05/05
[20] Bill Erickson, A Technique to Eliminate Cross-Polarization Responses and Mutual Interactions Between Circularly Polarized Antennas, 04/05
[19] R. Bradley and C.R. Parashare, Evaluation of the NRL LWA Active Balun Prototype (Rev.A), 02/05.
[18] A. Kerkhoff and S.W. Ellingson, "A Wideband Planar Dipole Antenna for Use in the Long Wavelength Demonstrator Array (LWDA)," 2005 IEEE Int'l Ant. and Prop. Symp., Washington, DC, July 2005, (1B: 553-6).
[17] A. Cohen, Estimates of the Classical Confusion Limit for the LWA, 12/04
[16] A. Cohen, Imaging Capability of the LWA Phase II, 12/04
[15] W. Erickson, An Approach to Ionospheric Calibration, 12/04
[14] E. Polisensky, Preliminary LWA Station Configuration Studies, 12/04
[13] T.J.W. Lazio and W. Farrell, Radio Detection of Extrasolar Planets: Present and Future Prospects, 10/04
[12] W. Erickson, Alternative Low-Band Antenna and Balun Designs, 11/03
[11] W. Erickson, A Study of Low and Mid-Range Dipoles for the LWA and LOFAR, 10/03
[10] N. Kassim, Thoughts on LWA FASR Synergy, 5/03
[9] C. Jackson, The Extraglactic Radio Sky at Faint Flux Densities, 10/02
[8] R. Perley and G. Bust, Probing the Ionosphere with the Very Large Array, 8/02
[7] R. Bradley and S. Srikanth, Broad Bandwidth Feeds for Reflector Antennas, 5/02
[6] V. Vilnrotter, Large Array Signal Processing for DSN Applications: Part I, 5/02
[5] T.J.W. Lazio, P. Crane, A. Cohen, and K. Weiler, LWA Sky, UV, & Galaxy Coverage, 3/02
[4] B. Hicks, W. Erickson and K. Stewart, NRL Low-Frequency Antenna Development, 3/02
[3] N. Kassim, LWA Data Management and Calibration, 5/01
[2] H. Falke and P. Gorham, Low Frequency Observations of Cosmic Ray Airshowers, 5/01
[1] R. Perley and W. Erickson, A Proposal for a Large, Low Frequency Array Located at the VLA Site, 4/84