US 11,733,367 B1
Chromatic correlation interferometry direction finding
Paul D. Zemany, Amherst, NH (US); David P. Charette, Hudson, NH (US); Matthew F. Chrobak, Groton, MA (US); and Court E. Rossman, Merrimack, NH (US)
Assigned to BAE Systems Information and Electronic Systems Integration Inc., Nashua, NH (US)
Filed by BAE SYSTEMS Information and Electronic Systems Integration Inc., Nashua, NH (US)
Filed on Apr. 14, 2021, as Appl. No. 17/230,011.
Int. Cl. G01S 13/42 (2006.01); F41G 7/22 (2006.01)
CPC G01S 13/42 (2013.01) [F41G 7/2246 (2013.01); F41G 7/2286 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A system for chromatic correlation interferometry direction finding (CIDF), comprising:
a transmitter configured to transmit signals at two or more frequencies;
a set of two or more antenna elements for receiving the signals;
signaling hardware configured to form I and Q data from the received signals;
a processor to control the signaling hardware and execute a chromatic CIDF algorithm, wherein the chromatic CIDF algorithm is:

OG Complex Work Unit Math
where:
|R(θt, ϕt)|2 Is the correlation squared function computed at testing angles (θt, ϕt)
Un Antenna voltages measured on a signal that is incident on the DF array
An(θt, ϕt) Array vectors retrieved from a calibration manifold
na number of DF antennas
wherein the term An(θt, ϕt) and Un are summed over frequency as well and become An,f(θt, ϕt) and Un,f and the sum is over elements (n) and frequencies (f); and
a pre-measured or pre-calibrated response manifold, or data table, for use in comparing with the received signals.