US 12,463,354 B2
Radio location finding
Timothy Paul Davey, Cambridgeshire (GB)
Assigned to CRFS Limited, Cambridge (GB)
Filed by CRFS Limited, Cambridge (GB)
Filed on Jan. 17, 2023, as Appl. No. 18/097,700.
Claims priority of application No. 2200553 (GB), filed on Jan. 17, 2022; and application No. 2201550 (GB), filed on Feb. 7, 2022.
Prior Publication US 2023/0231323 A1, Jul. 20, 2023
Int. Cl. G01S 5/14 (2006.01); H01Q 21/20 (2006.01)
CPC H01Q 21/205 (2013.01) [G01S 5/14 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of passively detecting a radio emission source, comprising:
receiving three or more radio signal datasets from three or more respective sensors, the three or more sensors spread across a region, each sensor corresponding to a physical location and comprising at least one radio receiver, wherein the three or more radio signal datasets comprise:
one or more directional datasets obtained using a directional antenna or a directional antenna array of the corresponding sensor;
two or more omnidirectional datasets, each obtained using an omnidirectional antenna or an omnidirectional antenna array of the corresponding sensor;
determining whether an emitter signal within a target frequency range is present in any of the one or more directional datasets of the three or more radio signal datasets;
for each given directional dataset of the three or more radio signal datasets, in response to the emitter signal is present in the given directional dataset, carrying out a time-difference-of-arrival location finding calculation based on temporal offsets determined based on cross-correlating the emitter signal in the given directional dataset against at least two other radio signal datasets of the three or more radio signal datasets.