Experimenting With Frequency‐And‐Angular Sounding to Characterize Traveling Ionospheric Disturbances Using the LWA‐SV Radio Telescope and A DPS4D

Abstract

AbstractHere we present near vertical angle of arrival and Doppler observations using a Digisonde Portable Sounder 4D (DPS4D) as a transmitter and the Long Wavelength Array at Sevilleta (LWA‐SV) radio telescope as a receiver, over an 80‐km baseline. With 256 dual‐polarization dipole antennas, LWA‐SV provides unparalleled sensitivity and angular resolution to high frequency sounding measurements of traveling ionospheric disturbances (TIDs). We conducted a study over 3 days in March 2018 and detected several TIDs ranging from 10‐ to 45‐min periods. These medium scale TIDs were detected using an implementation of frequency‐and‐angular sounding (FAS), which was first described in Beley et al. (1995, https://doi.org/10.1029/95RS01992). FAS assumes an ionospheric mirror model and provides estimates of the wavelength, direction, and speed of TIDs using the measured angle of arrival and Doppler of a high frequency ionospheric reflection. We experiment with this method and show that LWA‐SV is capable of achieving observations that are unmatched in sensitivity and resolution, allowing for measurements limited primarily by the errors accumulated by the assumptions within different manifestations of the FAS algorithm.