Patent ID: 11933882
Assignee: INSTITUT NATIONAL D'OPTIQUE
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for detection and synthetic aperture (SA) imaging of a target present in a scene, the method comprising:
performing a target detection phase using lidar remote sensing, the target detection phase comprising:
illuminating the scene along a search direction with a lidar search signal transmitted from a platform in relative movement with respect to the scene along a travel path to search for the target in the scene, the lidar search signal having an angular field of illumination;
receiving, on the platform, a search return signal produced by reflection of the lidar search signal from the target to detect the presence of the target in the scene; and
estimating, from the search return signal, a range and an angular location of the target; and

performing, following the target detection phase, an SA imaging phase using SA imaging, the SA imaging phase comprising:
generating an SA transmission signal and a local oscillator (LO) signal with a time delay therebetween, the time delay being based on the range of the target estimated in the target detection phase using lidar remote sensing;
illuminating the scene along an imaging direction with the SA transmission signal transmitted from the platform, the imaging direction being based on the angular location of the target estimated in the target detection phase using lidar remote sensing, the SA transmission signal used in the SA imaging phase having an angular field of illumination that is narrower than the angular field of illumination of the lidar search signal used in the target detection phase;
receiving, on the platform, an SA return signal produced by reflection of the SA transmission signal from the target;
mixing the SA return signal with the LO signal to generate SA signal data; and
generating an SA image of the target from the SA signal data.