TitleLow Frequencies on the NRAO VLA and the NRL VLA Low Band Ionospheric and Transient Experiment (VLITE)
Publication TypeConference Paper
Year of Publication2015
AuthorsKassim, N, Clarke, T, Helmboldt, J, Ray, P, Lane, W, Polisensky, E, Mroczkowski, T, Deneva, J, Hicks, B
Conference Name IAU General Assembly, Meeting #29
Date Published08/2015

The Karl G. Jansky Very Large Array (VLA), operated by the National Radio Astronomy Observatory (NRAO), has recently undergone an upgrade to a fully digital broadband system covering the frequency range of 1-50 GHz. The Naval Research Laboratory (NRL) has collaborated with NRAO to return lower frequencies to the VLA in a new broadband receiver system. This system covers two bands from 56-86 MHz (4-band) and 240-470 MHz (P-band). Currently, the P-band system is in regular use as part of the General Observing (GO) program, while the lower frequency band is undergoing testing with a new feed design.NRL and NRAO are now broadening the VLA low frequency capabilities through the commensal VLA Low Band Ionospheric and Transient Experiment. The operational VLITE system has dedicated samplers and fibers that tap the signal from 10 VLA P-band receivers and correlate those through a dedicated DiFX correlator. This commensal, low frequency system enriches the scientific output of the VLA with no added burden on higher frequency observations. VLITE is expected to obtain more than 3000 hours on sky per year at P band. Its primary scientific drivers are ionospheric science and astrophysical transients, complimented by imaging capabilities more robust than anticipated.We will review the improved low frequency capabilities at the VLA, and provide a status update for the commensal VLITE project, including initial science results. Contingent on VLITE’s scientific success, we will also describe plans on its expansion across the full low frequency capabilities of the VLA through the Low Band Observatory (LOBO). Discussion is also underway to explore incorporation of dipole-based Long Wavelength Array (LWA) stations into LOBO to enhance its lowest frequency imaging capabilities.See also http://vlite.nrao.edu and a recent press release at: http://www.nrl.navy.mil/media/news-releases/2015/astronomy-in-the-fast-l...