Synthetic aperture laser imaging radar receiving and transmitting system based on light beam coherent combination

Abstract

The invention discloses a synthetic aperture laser imaging radar receiving and transmitting system based on light beam coherent combination. The transmitting system of the invention comprises a laserlight source, a frequency modulator, an arbitrary waveform generator, a first light beam splitter, a second light beam splitter, an optical fiber amplifier group, a first photon lantern and a transmission lens. A receiving system of the invention comprises a receiving lens, a second photon lantern, a light beam coherent synthesizer, a frequency mixer, a balance detector and a signal demodulator. By use of the system, the optical toe and the imaging width degree of a target surface can be enlarged, and an imaging field of view is enlarged. In addition, the signal-to-noise ratio of the system isfurther improved, and an error rate is lowered. In addition, since the system reduces the use of the detector and the frequency mixer, cost can be greatly lowered so as to perform an important meaning for an airborne synthetic aperture laser imaging radar with long distance, high sensitivity and a high width degree.

Description

technical field [0001] The invention relates to a synthetic aperture laser imaging radar, in particular to a synthetic aperture laser imaging radar transceiver system based on beam coherent synthesis. Background technique [0002] Synthetic Aperture Imaging Ladar (Synthetic Aperture Imaging Ladar, referred to as SAIL) is the only optical imaging observation method that can obtain centimeter-level imaging sensitivity at a long distance. SAR) principle, in contrast, the light wave wavelength is 3-6 orders of magnitude smaller than the microwave wavelength, which brings the sensitivity of SAIL to be 3-6 orders of magnitude higher than that of SAR, and at the same time, the direct problem is that the field of view is smaller 2-5 orders of magnitude. At present, the maximum imaging field of view of airborne SAIL realized at home and abroad is 4.8 mrad, which is much smaller than that of SAR and CCD cameras (see: Lu Zhiyong, Zhou Yu, Sun Jianfeng, Luan Zhu, Wang Lijuan, Xu Qian, ...

AI Technical Summary

Problems solved by technology

Due to the use of multiple detectors, the incident optical power on each detector will inevitably be reduced. At the same time, each detector will introduce detector noise, which reduces the signal-to-noise ratio of the system and increases the bit error rate.

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