Bio-Inspired Electromagnetic Orientation for UAVs in a GPS-Denied Environment Using MIMO Channel Sounding

When external positioning systems are not available, other navigation methods must be used to guide unmanned air vehicles. We propose a bioinspired technique related to MIMO channel sounding for discriminating aircraft position and bearing. By analogy with the acoustic orientation used by certain bird species to return to a specific location in a dark cave, we refer to the proposed method as electromagnetic orientation (EO). A scattering model is used to generate simulated MIMO channel matrices for randomly generated propagation environments. Several variants of a basic propagation channel sounding-based method for EO discrimination are considered, including orientation with a single-frequency propagation channel matrix, channel covariance matrix, and broadband channel sounding data. At X band, the difference between a measured channel matrix and a stored, a reference channel matrix can be used to discriminate position to centimeter scale accuracy. Using the higher order correlation statistics of the channel matrix, the range scale can be increased to on the order of a meter. The method was used experimentally to localize the position of a UAV with channel probing data collected with a frequency modulated, continuous wave (FMCW) radar.