Joseph Helmboldt
Remote Sensing Division, Naval Research Laboratory
A Low-cost Radio Telescope Array for Ionospheric Remote Sensing
The Deployable Low-band Ionosphere and Transient Experiment (DLITE) is a four-element interferometric radio telescope made from mostly commercial off-the-shelf parts to minimize costs and maximize ease of deployment. It operates in the High Frequency (HF) and Very High Frequency (VHF) regimes, nominally in a 30--40 MHz band, but with good sensitivity (sky-noise dominated) in the 20-80 MHz range. Its configuration is optimized to probe ionospheric structure using the so-called "A-Team," exceptionally bright sources of cosmic radio emission. Methods have been developed to track the apparent positions and intensities of A-Team sources without the need for beam forming to enable measurements of VHF scintillations as well as total electron content (TEC) gradients. Time difference of arrival (TDOA) and frequency difference of arrival (FDOA) methods have been adapted for all-sky imaging to facilitate both statistical measurements of scintillation levels and time domain astronomy. This presentation will describe the system design, analysis algorithms, and science that can be conducted using results from prototype DLITE systems in Maryland, New Mexico, and Florida.