US 2008/0186235 A1 · Multiplatform TDOA correlation interferometer geolocation

Abstract

A radio geolocation system is described in which a plurality of moving platforms such as aircraft concurrently receive a signal from a remote transmitter and the geolocation of the transmitter is determined. At each platform every thirty seconds a plurality of samples of the received signal are taken over a one second period. The samples are digitized and a time and GPS location stamp are added to each sample. The digitized samples with time and location stamps from all platforms are transmitted to a central location and stored in covariance matrices, one matrix per one second sample period. The signal samples in each matrix are processed utilizing a unique algorithm to generate a data set which defines a correlation surface. The data from a plurality of data sets are summed together on a point by point basis and normalized to yield a summation data set which defines a summation correlation surface. The summation correlation surface has a well defined peak that defines the geolocation of the remote transmitter.

Claims20

Dependent claims

A method for locating a remote transmitter from which an electromagnetic signal is being received using an antenna and a receiver mounted on each of a plurality of moving platforms, and indicating the geolocation of the transmitter, the method comprising the steps of:

(a) obtaining a plurality of sets of samples of the electromagnetic signal received with the antenna and receiver on each moving platform, there being one set of samples received at each moving platform for each of a plurality of time periods;
(b) placing a time and location stamp on each of the signal samples obtained in step (a) indicating the time when and the location where each signal sample is taken;
(c) transmitting the signal samples received at each moving platform and having the time and location stamps thereon per step (c) to a central location;
(d) storing at the central location the set of signal samples transmitted in step (c) from each moving platform for each period of time;
(e) processing the stored set of signal samples from all the moving platforms for each period of time to produce an individual data set for each period of time;
and
(f) analyzing the data sets produced in step (e) to determine the geolocation of the remote transmitter.

4 more elements

(a) sampling the electromagnetic signal received at each of the moving platforms to produce a plurality of sets of signal samples that are digitized, there being one set of signal samples for each of a plurality of periods of time at each platform;
(b) adding a time and location stamp on each of the digitized signal samples obtained in step (a) indicating the time when and geolocation where each digitized signal sample is taken on a moving platform;
(c) transmitting each set of digitized signal samples with their time and location stamps from each moving platform to a common location for processing;
(d) storing the sets of digitized signal samples transmitted in step (c) to the common location in a covariance matrix for each of the plurality of periods of time;
(e) processing the sets of digitized signal samples received from all platforms for each of the plurality of periods of time to produce a like plurality of individual data sets;
(f) summing and normalizing all of the individual data sets produced in step (e) to produce a summation data set;
and
(g) analyzing the summation set of data produced in step (f) to determine the geolocation of the remote transmitter;

5 more elements

Dependencies are inferred from the claim text.

Multiplatform TDOA correlation interferometer geolocation

Life of this patent

Multiplatform TDOA correlation interferometer geolocation

Life of this patent

Abstract

Claims20