Frequency modulated continuous wave laser radar frequency modulation nonlinear response coefficient measuring method and device

Abstract

The invention provides a frequency modulated continuous wave laser radar frequency modulation nonlinear response coefficient measuring method. According to the method, a signal generator generates sawtooth wave frequency-modulated signals, inputs the sawtooth wave frequency-modulated signals into a driving circuit and drives a laser to work, modulation signal light output by the laser is divided into two paths through a first coupler, one path of light is emitted to a measured object through a circulator, return light returned by the measured object is received by the circulator, the return light and the other path of light are coupled through a second coupler, light output by the second coupler is received by a photoelectric detector, obtained beat frequency signals are processed through a signal processing circuit, difference frequency is obtained through processing of computer software and a nonlinear frequency modulation coefficient is worked out. The frequency modulated continuous wave laser radar frequency modulation nonlinear response coefficient measuring method can be used for accurately measuring the nonlinear coefficient, provides key parameters for frequency modulation nonlinear rectification for a system, and has great significance for improving the frequency modulation linearity of frequency modulated continuous wave laser radar range radar, and the accuracy of measurement of the speed and distance of the system .

Description

technical field [0001] The invention relates to frequency modulation continuous wave laser radar measurement technology, in particular to a frequency modulation continuous wave laser radar frequency modulation nonlinear response coefficient measurement method and device. Background technique: [0002] Due to the constraints of narrow linewidth laser technology and linear frequency modulation technology, the earliest radar using frequency modulation continuous wave technology is not lidar but microwave radar, but frequency modulation continuous wave microwave radar is restricted by factors such as detection accuracy. Therefore, with laser modulation With the development of technology and narrow linewidth laser technology, frequency-modulated continuous wave lidar has been widely used in space missions for distance and velocity measurement. [0003] Frequency-modulated continuous wave laser radar transmits linearly modulated laser signals to the target, receives the echo signa...

AI Technical Summary

Problems solved by technology

In practice, due to the influence of the environment and the response of the device itself, the modulated signal light emitted by the laser is not an ideal linear frequency modulation signal, so that the difference frequency signal after mixing the transmitted signal and the echo signal is no longer a single frequency. There will be errors in the extraction of frequency signals, which will lead to a decrease in the accuracy of the system's distance measurement and speed measurement.

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