Communications: directive radio wave systems and devices (e.g. – Synthetic aperture radar
Patent
1989-01-05
1990-05-29
Tarcza, Thomas H.
Communications: directive radio wave systems and devices (e.g.,
Synthetic aperture radar
G01S 1390
Patent
active
049299506
ABSTRACT:
In a synthetic aperture radar system, information concerning the radar reflectivity of a point on the ground is placed in an image at an azimuthal (cross-range) position which corresponds to the position of zero Doppler frequency shift of the received signal, under the assumption that the antenna has followed a straight line trajectory. In practice, the antenna trajectory will undergo small deviations about this straight line path which are not taken into account in the azimuth processing and which, consequently, cause incorrect azimuthal positioning in the image of the information concerning a point target on the ground.
The invention uses the value of the slope of the frequency modulation of the received signal, calculated by means of an autofocus procedure, to determine the intercept of this frequency modulation at successive azimuth positions. This true intercept value is then incorporated in the azimuth processing, instead of the assumed intercept of the frequency modulation, allowing imagery which is free from azimuthal positioning errors to be produced.
REFERENCES:
patent: 4134113 (1979-01-01), Powell
patent: 4163231 (1979-07-01), Zuerndorfer et al.
patent: 4219811 (1980-08-01), Herman et al.
patent: 4246580 (1981-01-01), Caputi, Jr.
patent: 4325065 (1982-04-01), Caputi, Jr.
patent: 4471357 (1984-09-01), Wu et al.
patent: 4562439 (1985-12-01), Peralta et al.
patent: 4563686 (1986-01-01), Boles
patent: 4594593 (1986-06-01), Nohmi
patent: 4602257 (1986-07-01), Grisham
patent: 4617567 (1986-10-01), Chan
patent: 4706088 (1987-11-01), Weindling
patent: 4706089 (1987-11-01), Weindling
patent: 4723124 (1988-02-01), Boles
patent: 4724418 (1988-02-01), Weindling
Blacknell et al, "Motion Compensation and Geometric Distortion in Airborne SAR Imagery", Progress in Imaging Sensors, Proc. ISPRS Symposium, Stuttgart, Sep. 1-5, 1986 (ESA SP-252, Nov. 1986), pp. 539-548.
Blacknell David
Finley Ian P.
Freeman Anthony
Oliver Christopher J.
Quegan Shaun
Sotomayor John B.
Tarcza Thomas H.
The General Electric Company plc
The Secretary of State for Defence in Her Britannic Majesty's Go
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