Distributed Shipborne HFHSSWR Localisation Method Based on Gaussian Markov Fields

This paper investigates a distributed shipborne high-frequency hybrid surface-surface wave radar (HFHSSWR) model that combines shared sky wave paths with distinct shipboard surface wave paths. This model improves target localisation accuracy and overcomes the limited aperture of a single shipboard array. A weighted least squares (WLS) positioning algorithm based on a Gaussian Markov random field (GMRF) is proposed for the model. The algorithm converts the geodetic coordinates of measurement stations to Cartesian coordinates, then estimates the initial target position using bistatic range (BR) and time difference of arrival (TDOA) measurements. An iterative refinement approach is employed to mitigate discrepancies between spherical and planar models, utilising ionospheric altitudes extrapolated through a GMRF for enhanced positioning accuracy. Finally, target coordinates are converted back to geodetic form. Simulations indicate that this approach achieves higher positioning accuracy than standard WLS positioning algorithm.