| 摘要 |
A Deramp type radar used in synthetic aperture radar for radar imaging transmits coherently repeated linear frequency-modulated pulses and carries out a sort of pulse compression in reception by demodulation of the echo signals received by means of a frequency ramp that reproduces all or part of a transmitted pulse, and by a Fourier transform performed in range. With this type of pulse compression, a parasitic phase modulation appears on the signal delivered by a Deramp type radar. This parasitic phase modulation disturbs the standard SAR procession operations for the construction of radar images. The proposed method is used to eliminate the detrimental effects of this parasitic phase modulation on the construction of a radar image. It consists of the adoption of a particular temporal support for the demodulation and of the correction of the parasitic phase modulation that appears with this particular temporal supports chiefly by a phase correction in the pulse response of the image focusing filter and, secondarily, by a another phase correction in the complex reflection coefficients obtained for the points of the image at the end of the SAR processing. FIG. 7.
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