Closed loop calibration network for synthetic aperture radar calibration and method for calibrating and compensating error

Abstract

The invention discloses a closed loop calibration network used for calibrating a transmission channel inside a synthetic aperture radar system. The closed loop calibration network comprises an attenuation unit, an optical fiber delay unit, a receiving front end, a digital intermediate frequency acquisition unit, and a digital demodulation and error analysis unit, wherein the attenuation unit is used for adjusting the amplitude of radio frequency microwave signals which are transmitted by a synthetic aperture radar to ensure that the amplitude of the radio frequency microwave signals which arereceived by a back end is in an allowable range; the optical fiber delay unit is used for adjusting the received time of the radio frequency microwave signals, converting the radio frequency microwave signals which are adjusted and output by the attenuation unit into optical signals, and recovering the optical signals into the radio frequency microwave signals through optical fiber transmission delay; the receiving front end converts the recovered radio frequency microwave signals into intermediate frequency analog signals; the digital intermediate frequency acquisition unit is used for digitally acquiring the intermediate frequency analog signals, an input end is connected with an output end of the receiving front end, and the intermediate frequency analog signals are converted into digital intermediate frequency signals by a high speed analog digital conversion circuit; and the digital demodulation and error analysis unit is used for demodulating digital acquisition signals, analyzing systematic errors, performing imaging compensation, and connecting an output end of the digital intermediate frequency acquisition unit.

Description

technical field [0001] The invention belongs to the technical field of synthetic aperture radar (SAR) calibration, and in particular relates to a closed-loop calibration network for synthetic aperture radar calibration. [0002] The present invention also relates to a method for realizing high-precision measurement and error compensation of the system transfer error of the high-resolution synthetic aperture radar by using the above-mentioned closed-loop calibration network. Background technique [0003] Synthetic Aperture Radar (SAR) is a high-resolution microwave imaging radar that can detect ground targets with high resolution and has the advantage of being all-weather and all-weather. Since the appearance of the aperture synthesis method in the 1950s, SAR systems have been widely loaded on aircraft, satellites, UAVs and other flying platforms for the detection of ground targets. It has been widely used in military reconnaissance and other fields. [0004] With the conti...

AI Technical Summary

Problems solved by technology

The above errors will have adverse effects on the imaging results, leading to the broadening of the main lobe and the lifting of the side lobes of the range-oriented pulse compression shock response, and the reduction of resolution and image quality. Therefore, the closed-loop calibration network analysis and extraction Thus providing system error compensation parameters

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