Correlation interferometer geolocation

Geolocation solutions based on the correlation interferometer geolocation (CIGL) equation depend on searching over (xⁱ,y ⁱ) space and identifying the transmitter location as the (x,y) value that maximizes the correlation value. Under cross-polarized incident field conditions this correlation depends on both the array manifold calibration polarization and the targets transmission polarization. Computation of the transmitted polarization is accomplished by maximizing the CIGL equation over polarization parameters for each measurement. Modifying CIGL to include superresolution and copy aided exploitation techniques is a straightforward process which improves geolocation accuracy under many operation conditions. Operational systems must contend with numerous error sources which will degrade geolocation accuracy, but CIGL accuracy improvements relative to conventional direction finding (DF) transmitter fixing are observed

Introduction

Correlation Interferometer GeoLocation (CIGL) accurately fixes the geolocation of remote transmitters without the use of conventional direction finding techniques and extensive DF antenna arrays. CIGL receives and records sets of transmitted signal measurements as a sparse calibrated array is spatially translated, which in most cases will occur during aircraft flights. Correlation surfaces are developed by correlating these recorded array voltages with calibrated array testing voltages that are indexed relative to x-y grid locations that cover the surface area of interest. The summation of these correlation surfaces has a maximum that is in the near neighborhood of the x-y grid point that contains the transmitter.