Space-borne laser range finder detection and feedback method and system based on digital constant false alarm

Abstract

The invention discloses a satellite-borne laser distance measuring instrument detection and feedback method and system based on a digital constant false alarm. The satellite-borne laser distance measuring instrument detection and feedback method includes the steps that noise received in a specific area is measured and counted many times to obtain a mean value and a root-mean-square value, according to obtained noise statistical results, the bias voltage of an avalanche diode is adjusted to make the bias voltage of the avalanche diode change along with changes of environments, temperature and the like, and therefore constant control on a false alarm rate is achieved; when topographic parameters change rapidly, the false alarm is controlled to be constant by adjusting an echo pre-authentication threshold value. A feedback algorithm overcomes the defect that according to a satellite-borne laser distance measuring instrument, output noise changes dramatically due to changes of a solar elevation angle; the noise is accumulated and counted many times, so that influence on subsequent measurement of a singular point which is introduced due to large topographic relief is eliminated; cloud layer scattering false echoes are identified and filtered out, through a digital control method, under the condition of meeting system detection probability requirements, the false alarm rate of on-orbit echoes is reduced, and distance values are obtained rapidly and accurately.

Description

technical field [0001] The invention belongs to the field of spaceborne laser radar optical remote sensing signal detection, and relates to a detection and on-orbit feedback method and system based on digital constant false alarm, which improves the adaptability of the change of the sun altitude angle caused by the high-speed operation of the satellite platform; improves the laser rangefinder It is adaptable to complex terrain with large roughness fluctuations and high reflectivity, and improves the ability to identify false echoes scattered by clouds to meet the requirements of false alarm rate and detection probability. Background technique [0002] Avalanche diodes (APDs) are usually used as receiver focal plane detectors for spaceborne laser range finders. APD is extremely sensitive to background noise, and the output signal and noise vary with the APD multiplication factor, and there is an optimal value for the multiplication factor. Under this optimal multiplication, ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a detection and on-orbit feedback method and system based on digital constant false alarm, and to solve the problem that the spaceborne rangefinder is vulnerable to the high speed and large jitter of the satellite platform. The impact of the echo signal is difficult to extract, the cloud scattering causes false echoes, and the false alarm rate is high for complex terrain with large roughness fluctuations and large reflectivity.

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