Long Wavelength Array
Radio telescope in central New Mexico
From Wikipedia, the free encyclopedia
The Long Wavelength Array (LWA) is a radio telescope in central New Mexico. It began preliminary tests of the hardware in 2011, and began regular operations in late 2015.[1] It is one of the few observatories to utilize relatively low frequencies (10-88 MHz), and is used to study relativistic particles, cosmic evolution, astrophysical plasma, decametric radio emissions from Jupiter-like extrasolar planets, and giant flares from magnetars.[2]
| Location | New Mexico |
|---|---|
| Coordinates | 34°04′N 107°38′W |
| Wavelength | 3.4 m (88 MHz)–30 m (10.0 MHz) |
| Diameter | 100 yd (300 ft 0 in) |
| Collecting area | 6,500 m2 (70,000 sq ft) |
| Website | lwa |
  Location within the United States | |
The goal is to build 50 to 53 stations in total, with a total of 13,000 dipole antennas[3] strategically placed in an area nearly 400 kilometres (250 miles) in diameter to scan the sky at HF and VHF frequencies.[4] Each antenna stands about 1.5 metres (5 ft) high and about 2.7 metres (9 ft) across the base.[5]
The array is officially recognized as an SKA pathfinder project.[6]
The project is a collaboration between UNM, VT, LANL, JPL, NRL, UI, BIRS, NRAO and AFRL.[7][clarification needed]
History
The program began in 2006 under the support of the Office of Naval Research.[8]
The first station, located adjacent to the NRAO's VLA, consists of 256 antennas and was completed in December 2009. It was dedicated in April 2010, and routine operations began in 2011.[3]
The second station (LWA2) was under construction about 19 km (12 mi) away as of 2011[update].[9] The array later came to be known as the LWA-SV.
In 2012, the LWA announced that they have successfully become a University Radio Observatory and is sponsored by the National Science Foundation. They also announced the first round of results from the LWA-1.[10]
LWA-SV (Sevilleta) consists of 256 antennas located in the Sevilleta National Wildlife Refuge.[6] The LWA team installed the electronics shelter in April, 2014[11], and the array was subsequently completed on October 17th, 2015.[12]
System Overview
The system is primarily based in New Mexico, with the core being within the vicinity of the Very Large Array. The system, as of 2026, consists of two ful stations each featuring 256 antennas and a mini-station of 64 elements. There are currently two additional mini-stations under construction at Texas Tech University and Arizona State University.[6] The system was designed with two main goals: scientific discoveries and student S&T trainings. Hence, the system is designed to be modular for hands-on testing and verifications, while being able to innovate with the pace of technology. The system also comes in standardized parts and blueprints so as to enable future expansions.[13]
Three data products can be obtained from the LWA-1 array, namely TBW, TBN, and DRX, with one additional data product originally obtainable now inaccessible owing to unknown reasons. For the LWA-SV array, there are four products obtainable, namely TBF, TBN, DRX, and COR.[14] The system operates with the range of 10MHz to 88 MHz, producing a cumulative 1TB per hour.[8]
The sites currently (as of October, 2026) operational are[6]:
- LWA-1: full station, consists of 256 elements
- LWA-SV: full station, consists of 256 elements
- LWA-NA: mini-station, consists of 64 elements
The mini-stations come in two formations, 48-element-type and 64-element-type. The LWA-NA originally came in the 48-element-type but was eventually upgraded to a 64-element-type. Upgrading from 64-element-type to a full station of 256 elements is also possible. Each mini-station part cost approximately $112,000 to build and around $7,000/year in upkeep, and the full station cost $1M each to build.[15]
The sensitivity of the system is drastically higher than that of the LOFAR, which is already higher than the VLA, coming with a SEFD of around 1 MJy when using a single antenna and <10 KJy when measured per station.[13]
Extended Long Wavelength Array
The Extended Long Wavelength Array (ELWA) is formed in conjunction with 27 antennas from the Very Large Array. The project started in 2018 and operates with a bandwidth of 10 MHz.[8]
