There are several ways to get involved with the Long Wavelength Array, ranging from a single antenna to a full LWA station. Whether you are an amateur radio astronomer, an educator, or a researcher at a university, there is an entry point for you.
The simplest way to get started with low-frequency radio astronomy is with a single LWA antenna. The LWA antenna is a broadband crossed-dipole design covering 10–88 MHz that can be purchased as a kit from Whit Reeve. A single antenna paired with a software-defined radio can be used for monitoring solar and Jovian bursts, observing meteors, and exploring the low-frequency radio sky. See the Public Outreach page for more information.
The Deployable Low-band Ionosphere and Transient Experiment (DLITE) is a four-element interferometric radio telescope built from LWA antennas and commercial off-the-shelf software-defined radios for approximately $40,000 in parts (in 2020 dollars). DLITE operates in the 20–80 MHz range and is optimized for ionospheric remote sensing using bright cosmic radio sources, but is also capable of time-domain astronomy including monitoring solar and Jovian radio bursts. For a full description of the instrument and its capabilities, see:
Helmboldt, J. F., Markowski, B. B., Bonanno, D. J., Clarke, T. E., Dowell, J., Hicks, B. C., Kassim, N. E., & Taylor, G. B. (2021). “The Deployable Low-band Ionosphere and Transient Experiment.” Radio Science, 56, e2021RS007298. doi:10.1029/2021RS007298
An LWA station consists of dual-polarization dipole antennas with associated analog receivers, digital processing hardware, and a computer for data acquisition and imaging. Stations are capable of imaging the sky, searching for cosmic rays and fireballs, and participating in the LWA Swarm as a VLBI element.
Stations come in two sizes. A mini-station uses 48–128 dipoles and balances imaging capability with cost—roughly $112,500 in materials for a 48-element station (in 2020 dollars), scaling roughly linearly with the number of dipoles. A full station uses 256 dipoles spread over an area roughly 110 m × 100 m, with a materials cost of approximately $600,000 (in 2020 dollars). Mini-stations use a core layout matching the full station design plus a Gaussian-tapered distribution of outer dipoles, making it straightforward to expand to a full station as funding becomes available.
For details on station design and the Swarm concept, see LWA Memo #210. For a practical account of what is involved in building a 64-element mini-station, see LWA Memo #226: LWA-NA Construction (C. Taylor, G. B. Taylor, & J. Dowell, 2023).
For more information about getting involved with the LWA at any level, please contact us at lwa@unm.edu.