System and method for calibrating spot position of laser altimeter in low temperature environment

Abstract

The invention discloses a system and method for calibrating the spot position of a laser altimeter in a low-temperature environment. The system of the invention includes: a reference voltage source, a temperature sensor, an operational amplifier, a voltage dividing resistor, a triode, a large sampling resistor, a photodiode, a span Impedance amplifier, inverting amplifier, gain-adjustable amplifier module, multi-channel comparator, multi-channel trigger, voltage regulator chip, voltage divider exclusion, LED display module; the invention can capture the laser light of the laser altimeter in the extremely cold polar region The energy level of the light spot is recorded and read by the researchers, and the center position of the light spot of the laser altimeter is finally calculated through computer processing, so as to achieve the purpose of calibrating the pointing angle error of the laser altimeter.

Description

technical field [0001] The invention belongs to the technical field of laser detection, and in particular relates to a system and method for calibrating the spot position of a laser altimeter in a low-temperature environment. Background technique [0002] The GF-7 spaceborne laser altimeter is an earth observation laser altimetry system independently developed by my country. It can accurately measure the distance between the satellite and the ground, combined with the position and attitude information of the satellite platform, it can provide high-precision Ground laser footpoint position data. During the on-orbit measurement of the GF-7 spaceborne laser altimeter, its performance indicators will be reduced to varying degrees due to the interference of its own system error and environmental factors, which will affect the accuracy of the laser altimeter's observation results. Therefore, the spaceborne laser altimeter needs to be calibrated strictly for its key indicators befo...

AI Technical Summary

Problems solved by technology

At present, the laser pointing angle error is the main factor affecting the observation performance of the spaceborne laser altimeter. However, because the GF-7 satellite platform does not have the attitude maneuverability, the development of laser pointing for the GF-7 spaceborne laser altimeter The laser detector for angular error calibration is the prerequisite for its on-orbit calibration, which will provide the required data support for the calibration of the laser pointing angle system error, and is also the key to ensuring the availability of the observation results of the GF-7 spaceborne laser altimeter

[0003] Due to the characteristics of low air pollution, less vegetation, flat surface, and rich satellite cross-heavy orbit data in extremely low-lying areas, it has an irreplaceable advantage in the calibration of satellite pointing angle errors. It will fail in low temperature environment, and general communication electronic equipment will also fail in low temperature environment. Therefore, in order to calibrate the satellite pointing angle in the harsh low temperature environment in extremely low areas, a device that can also be used in extremely low temperature conditions is required. Laser active detectors in normal use

[0004] The problem with the laser active detector designed for the GF-07 spaceborne laser altimeter used in polar regions is that the detector must be able to work normally under polar low temperature conditions, and due to low temperature conditions, traditional laser detectors cannot be used. Obtain the energy level information of the detector through wired or wireless communication, and the detector outputs energy level information through other means

[0005] The sensitivity of the detector should match the energy density of the ground laser foot of the spaceborne laser altimeter. If the sensitivity is too high, the detector will be saturated and lose linearity. If the sensitivity is too small, the detector will not be able to respond to the laser pulse.

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