US 11,789,112 B2
Observation apparatus, observation method, and program
Toshihiro Sezai, Tokyo (JP)
Assigned to Japan Aerospace Exploration Agency, Tokyo (JP)
Appl. No. 17/283,763
Filed by JAPAN AEROSPACE EXPLORATION AGENCY, Tokyo (JP)
PCT Filed Feb. 20, 2019, PCT No. PCT/JP2019/006289
§ 371(c)(1), (2) Date Apr. 8, 2021,
PCT Pub. No. WO2020/075319, PCT Pub. Date Apr. 16, 2020.
Claims priority of application No. 2018-191298 (JP), filed on Oct. 9, 2018; and application No. 2019-022337 (JP), filed on Feb. 12, 2019.
Prior Publication US 2021/0389413 A1, Dec. 16, 2021
Int. Cl. G01S 7/02 (2006.01)
CPC G01S 7/02 (2013.01) 9 Claims
OG exemplary drawing
 
1. An observation apparatus, comprising
an antenna system comprising an antenna; and
a processor in operable communication with the antenna, wherein the processor
performs, using a square root signal of a received electric power signal from an antenna whose beam is scanned within a predetermined azimuthal angle range and a signal of an azimuthal angle of the scanned beam, a Fourier transform with respect to the azimuthal angle on the square root signal,
divides a first azimuth frequency signal by a second azimuth frequency signal, the first azimuth frequency signal being obtained by performing the Fourier transform, the second azimuth frequency signal being obtained by performing a Fourier transform with respect to the azimuthal angle on a square root signal of an antenna electric power pattern, and
fits the divided signal with exponential functions including real parts and imaginary parts in arguments by using Prony's method.