Sensitivity Analysis of Localization Using Discrete Astronomical Radio Sources

Although GPS is the most common method used for localization, it is sometimes insufficient due to its unavailability or unreliability. Therefore, signals of opportunity (SOP) arise as a promising alternative solution in such situations. In this paper, we examine a new technique for determining the location of devices based on novel (and naturally occurring) signals of opportunity rather than a fixed infrastructure. Precisely, our technique is based on tracking the sidereal motion of discrete astronomical radio sources (e.g., supernova remnants or radio galaxies). Unlike other types of SOP and GPS alternatives, our technique has the advantage of using permanent sources. In other words, since the sources are naturally occurring, they have the advantage of being permanent; they can't be disabled or shot down, and don't have any maintenance issues. These sources are also readily detectable at radio frequencies over a continuous range from HF through SHF, making jamming difficult. Given two antennas acting as an interferometer, the fringe rate (the rate at which the phase of the correlation of the discrete astronomical radio source being tracked for localization purposes changes) is estimated, and used for identifying the interferometer location in latitude and longitude. In this paper, building on our previous work, we perform a sensitivity analysis of our proposed technique. Specifically, we examine the impact of the baseline geometry, the estimation of the interferometer baseline, and the impact of the specific fringe rate value on the performance of the technique. Our results demonstrate the potential usefulness of the technique.