LWA Memo Series
Technical documents on all aspects of the project.

June 24, 2009 - The First of the Summer Summer 2009 Work Parties
                        re construction at the LWA-1 station

The first summer work party at the LWA-1 construction site was held on Wednesday June 24. Adam Martinez, Graduate Research Assistant in Civil Engineering is the Manager of the summer construction crew which consists of undergraduate and graduate students from Civil Engineering. Among the senior LWA staff participating in the work day were Lee J Rickard, Executive Project Director, and Walter Gerstle, Civil Engineering Professor. Three UNM undergraduate majors in Astrophysics did most of the heavy work.

The day's work plan included the following projects:
1) trenching of a couple of long tracks - by the summer crew of Civil Engineering graduate students.
2) putting conduit and junction boxes into the trenches and covering up the trenches with dirt - done by the Astrophysics undergraduate students.
3) cutting short pieces of conduit for the short distance from the ground to the top of the blade antennas - done by John and Lanie Dickel (both UNM Adjunct Professors in Physics/Astronomy)
4) attaching a connector to one end of each of the short pieces of conduit - the undergraduate students took over from Lee J Rickard.
All four projects were completed by the end of the day.

In addition Adam Martinez, Walter Gerstle, and John Dickel confirmed that it was possible to string an extra cable through a long conduit between 2 junction boxes that was already filled with 28 other cables. This test needs to be repeated over a longer distance.

Photos are posted on the Progress thru photos   and Education   pages.
Additional photos (original size) are available for download from the LWA wiki pages.

June 2, 2009 - Construction of the first LWA station begins

Construction of the first station of the LWA began on June 2nd and is progressing well. Surveying has been completed and the current focus is on trenching for the conduits. As of June 16th, one full branch has been trenched and laden with conduit. The shelter has been ordered.

First photos are on the Progress thru photos   page.
Additional photos are available for download from the LWA wiki pages.

June 1, 2009 - LWA Review for Long Lead Items

A meeting of LWA staff, Review Committee members, UNM officials, professors, and graduate students was held June 1, 2009 on the UNM campus to present and discuss the current status and upcoming plans regarding the construction of the first station of the Long Wavelength Array.

Photos on the Progress thru photos   page.

Power Point Presentations available for download from the LWA wiki pages.

May 27-28, 2009 - Fencing completed at LWA site 2

UNM civil engineering graduate students completed installing the fencing around the site 2 of the LWA.     Selected photos are available on the   Progress thru photos   page.

April 1, 2009 - LWA Press Release

Commissioner of Public Lands, UNM Sign Agreement to Begin Construction on Long Wavelength Array Sites

Commissioner of Public Lands Patrick Lyons and the University of New Mexico today signed an agreement to commence construction of the first two sites of the Long Wavelength Array (LWA) on state trust lands in Catron and Socorro counties. Centered on the plains of San Agustin, the best site for radio astronomy in North America, the LWA will complement and share key infrastructure with the major National Science Foundation Very Large Array (VLA), located in Socorro. The LWA will provide high-precision, synoptic views of the ionosphere and solar weather events, and of a variety of astrophysical phenomena. Research and development conducted over several years is now complete and the LWA project is ready to break ground.

April 2009 - Revised Logo strips and Poster templates

The Logo strips and Poster templates have been revised to include the BIRS - Bruny Island Radio Spectrometer which was developed by Bill Erickson. -   click   here   for these items.

March 16-19, 2009 - Spring break work week at the site

UNM students surveyed, trenched, pulled cables through conduit, and conducted various tests on the new Oz-post under the direction of Joe Craig, LWA Programs Operations Director with the assistance of Adam Matrinez, graduate student assistant in Civil Engineering (working under Prof. Walter Gerstle). All the photos are available in a power-point file and the associated document describes the daily schedule and accomplishments.
Selected photos are available on the   Progress thru photos   page.

January 2009 - Experiments with trencher

A riding trencher was rented and trenches made at the LWDA site. Curved as well as straight trenches were dug. To make intersecting trenches, one can not just trench across an existing trench but one backs up to the edge of it. In sandy soil this trencher was less likely to cause a cave-in compared to an earlier hand-pushed trencher. Selected photos are available on the   Progress thru photos   page.

January 2009 - New Logo strips and Templates

New logo strips and poster templates have been created in which ARL is replaced by JPL. -   click   here  

December 2008 - UT/ARL withdraws from LWA Project

The Applied Research Team from the University of Texas was responsible for many important aspects of the project, as well as earlier work with NRL rooted in Kassim's Accelerated Research Initiative - most notably the LWDA. They have completed their previous technical work and have no additional interest in the current technical work. They will be missed.

November 2008 - New Mobile Workstation

The new mobile workstation is being fitted up for operation at the sites. Thanks to support from the Department of Physics and Astronomy at UNM, there is now a truck available to tow the workstation. The outside and inside of the mobile workstation may be viewed on the   Progress thru photos   page.

November 24, 2008 - Power Line Interference Test

November 24, Tremblay and Kuniyoshi did RFI measurements on low voltage power lines in coordination with the Socorro Electric Cooperative, from whom we get our power. The basic result is that the impact is very modest over the range 1 to 100 MHz.

November 22, 2008 - LWDA - RTA Trench and Re-cabling

Trenching between the LWDA site and the RTA site (300m away) was carried out on November 22. This work enables us to do some measurements of the effects of dispersion in the cable under the varying environmental conditions. The trenching may be seen on the   Progress thru photos   page.

October 2008 - Project Time-line updated - see   Summary Table  

October 2008 - $2.8 million allocated to UNM for LWA

Of the 4th consecutive funding awarded for the LWA project, $2.8 million was allocated to the University of New Mexico to support their effort on Long Wavelength Array project.

September 2008 - The Jet Propulsion Laboratory joins the LWA Project.

September 2008 - "Brassboard" Analog Receiver designed and tested.

The "Brassboard" Analog Receiver for the LWA was designed and tested at UNM by Joe Craig, LWA Systems Engineer.

A photograph of the analog receiver and the test spectrum may be found on the
Progress thru photos     page.

September 2008 - Five LWA sites approved

The FEMA CATegorical EXclusion (CATEX) has been signed and filed. This brings the number of LWA sites which have satisfied the Federal environmental permit process to 5 (LWDA + 4 with this action). The completion of the CATEX is a major step forward in the site acquisition.

A map showing the locations of the five sites and photos of the 4 new sites may be viewed on the     Progress thru photos     page.

August 2008 - URSI & Low Frequency Software meetings held in Chicago

Steve Ellingson and Ylva Pihlstrom gave invited talks at URSI and Ylva organized a one-day session on Low Frequency Software. LWA consortium members were well represented at both with their talks and posters. We hope that this will foster an increase in collaboration between various other groups and the LWA consortium.

June 2008 - Prof. Patricia Henning elected Vice-Chair of US Square Kilometer Array Consortium.

UNM Department of Physics and Astronomy Assoc. Professor, Patricia Henning, begins 3-year term as Vice-Chair of the United States Square Kilometer Array Consortium on July 1, 2008.       UNM Announcement

February 2008 - Joe Craig hired as LWA Programs Operation Director

January 2008 - LWA Systems Requirement Review passed

The LWA Project completed its System Requirement Review (SRR) in January 2007 following a review by our highly capable Technical Advisory Committee. This keeps us on track for a Preliminary Design Review (PDR) in late Spring of 2008.

July 2007 - Virginia Tech and The University of Iowa join the LWA Project.

April 2007 - Dr. Lee J. Rickard hired as LWA Executive Project Director.


- Before April 2007 -

What follows was created before the hiring of the Executive Project Director.

A word of caution - as a project unfolds, details change so one should expect to see some inconsistencies arise - such as in the designation of the different stages of the project - for which we apologize.

Daily Dynamic Spectra from the LWDA site

The Specmaster spectrum monitoring system was recently developed by Brian Hicks and Nagini Paravastu at NRL. The GUI-driven system is controllable either locally or remotely (Internet), and was installed at the LWDA site by NRL's Paul Ray in July 2006. Its output is now available at our Specmaster Data website, developed by Robert Duffin (NRL/GMU), allowing one to view Daily Dynamic Spectra and special events from the "Big Blade" antenna at the LWDA site.

Measurements are now being obtained by our "Big Blade" antenna, featured in the top right panel at the Specmaster Data website. Larger than any of the 16 antennas that comprise the LWDA, Big Blade is a working prototype of the broader-bandwidth LWA dipoles that will operate over ~20-80 MHz. It is currently attached to our Specmaster spectrum analyzer that allows us to generate daily broad-band spectra. This is an important ongoing monitoring activity that is allowing us to develop a statistical characterization of the RFI environment around the LWDA site. So far, with the exception of a few well known bright narrow-band interfering signals, much of the LWA band appears relatively clean. We occasionally detect transient bursts from the sun, and as shown at the Specmaster Data website some of these events are being compared to simultaneous measurements obtained at other frequencies.

LWDA - Milestone Passed

First light with new receivers on 16 dipoles of LWDA - October 23, 2006

During the second half of October, Johnathan York, Aaron Kerkhoff, Charlie Slack and John Copeland from ARL:UT completed the installation of the LWDA hardware at the site and all is working beautifully. This includes both polarizations for all 16 dipoles, all 16 baluns, all the cables,the analog gain stages, the digital receivers, the adder boards, the control computer, the GPS receiver, the networked UPS, the internet switch, and the new A/C for the shelter. This is a major achievement; congratulations to everyone at ARL:UT who helped accomplish this, especially the four who spent an intense week in the desert getting it all together.

In addition, they were able to do careful phase and gain calibration of each of the antennas in the array and the calibrations look great. The phase calibrations were repeated on two different days and matched to better than 100 ps. Johnathan implemented a mode in the LWDA software to cycle through the array baseline by baseline doing a software FX correlator on each baseline, using the full 1.6 MHz bandwidth of the receiver. In this mode, it can measure all 120 visibilities in just a few seconds, and construct an image by superposing the 120 sine waves with the measured amplitudes and phases. Johnathan did this and had the process repeat all night. The result is shown in a great movie posted on the LWDA web page (click link above).

This is a major accomplishment - you can see Cas A, Cyg A, and Sgr A easily in the movie; there are hints of other sources, but obviously sidelobe confusion is a big issue. The next step which the team is planning is to integrate for several hours and clean the map.