Patent ID: 6384766
Filing Date: 2002-05-07
Classification: G01S

Abstract:
A method for generating a three-dimensional image of a ground area by means of a radar with a synthetic aperture which is moving in an essentially rectilinear manner and includes at least two antennae, comprising the steps of:creating at least two images of the ground with a large difference in the angle of illumination, transmitting radar pulses with a fractional bandwidth which is larger than or equal to 0.1, and using in the computations an aperture angle which is larger than or equal to 0.1 radians, detecting reflected radar pulses from said transmitting radar pulses, said reflected radar pulses having amplitude and phase, for each transmitting radar pulse of said transmitting radar pulses, measuring and storing position data of the antenna transmitting and for each reflected radar pulses measuring and storing position data of the antenna receiving the reflected radar pulse, computing a two-dimensional SAR signal having an amplitude and phase per synthetic aperture, and, reconstructing a three-dimensional position topography of an area relative to said antenna position data, the topography being inverted from the measured SAR signals, determining a topography with a coarse resolution and with a limited depth of focusing using the amplitude of the SAR signals, and determining an unambiguous topography of a fine resolution using the phase of the SAR signals by comparing with a starting geometric signal model with the topography of the area and the position data of the antennae as input parameters.