Generation of VHF ground clutter map employing partially cooperative transmitter

A Doppler VHF Omnidirectional Radio range (DVOR) radiates an omnidirectional signal that is used to generate a ground clutter map of reflective objects in this Passive Bistatic Radar (PBR) application. The derivation of the clutter map and its RCS values are discussed in this paper. The data are finally used as preload parameters to forecast the degradation of the VOR angular bearing when used for aircraft navigation. A small aircraft carrying a VHF sensor performs an orbit flight around the transmitter. Two signal properties are analyzed: Doppler shifts from the direct to the scattered signal deliver the difference of incident angles for all scatterers. Secondly, the DVOR inherently transmits a signal that has a directional-sensitive frequency modulation component which means that the PBR transmitter is partially cooperative. A Matched Filter is used to derive that directional information from the same scatterers, which then allows their localization by means of a cross bearing. Since the system is strictly linear, specific RCS values can be assigned to reflective objects on ground.