Doppler radar low-speed measurement method

Abstract

The invention discloses a Doppler radar low-speed measurement method. The Doppler radar low-speed measurement method is mainly used for solving the problem that an existing continuous wave Doppler radar cannot measure the speed when an aerial carrier hovers and flies at the low speed. According to the realization scheme, the Doppler radar low-speed measurement method comprises the steps that 1, anantenna cover of a Doppler radar is thickened, the selected position of the edge of the antenna cover of the Doppler radar is coated with a matched wave-absorbing material, and the standing-wave ratio of a microstrip antenna and radio frequency transceiver cross-linking interface is controlled; 2, the wave-absorbing material is pasted on the upper part of a radio frequency transceiver of the Doppler radar; 3, an amplifying circuit in an intermediate-frequency receiver of the Doppler radar is adjusted, and the intermediate-frequency receiver is optimized; 4, the intermediate-frequency receiveris subjected to AGC control in a mode of combining a PID algorithm and a linear algorithm; 5, the radar wave beam switching period is prolonged; and 6, a low-speed signal of the aerial carrier is measured under the clearance measuring environment through the Doppler radar improved by the steps 1-5. According to the Doppler radar low-speed measurement method, the low-speed measurement ability of the continuous wave Doppler radar is improved, and the Doppler radar low-speed measurement method can be used for stale speed measurement during hovering or low-speed flying of an aircraft.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular relates to a low-speed speed measurement method of a Doppler radar, which can be used for stable speed measurement when an aircraft is hovering or flying at a low speed. Background technique [0002] Doppler radar uses the Doppler effect to accurately measure the three-axis velocity of the carrier aircraft. The radar transmits and receives electromagnetic waves, and calculates the three-axis relative velocity between the radar carrier and the reflecting surface by calculating the frequency difference between the received electromagnetic wave signal and the transmitted electromagnetic wave signal. [0003] According to the characteristics that the frequency received by the frequency receiver changes with the relative movement between the receiver and the frequency emitter, the difference between the receiving frequency and the transmitting frequency is calculated by the Doppler eff...

AI Technical Summary

Problems solved by technology

[0006]At present, Doppler radar generally adopts a simple continuous wave system, which has a shortcoming, that is, the leakage of radar signals and the low-frequency modulation signal caused by beam switching can easily cause radar mistracking Signals near zero frequency

In order to prevent this kind of false tracking, a band-pass filter is usually used to suppress the zero-frequency signal and low-frequency modulation signal, but at the same time, it also suppresses the Doppler frequency shift signal when the aircraft is flying at a low speed.

[0007] When the adopted band-pass filter suppresses the zero-frequency and low-frequency signals to a large extent, the Doppler frequency shift signal at low speed will also be suppressed very much Low, the radar cannot track the Doppler frequency shift signal at low speed, that is, the sensitivity of the low-speed signal is low, and the Doppler radar will lose lock when the aircraft is hovering and flying at low speed, resulting in the Doppler radar not being able to perform low-speed measurements

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