Dual polarization radar arbitrary polarization wave on-line calibrating method

Abstract

The invention relates to a dual polarization radar arbitrary polarization wave on-line calibrating method. A polarization calibrating channel is constituted by a digital calibrating unit, a digital-to-analog converter, a frequency converter, a calibrating horn, a main feed source horn, and a receiving channel. The digital calibrating unit is substantially an arbitrary waveform generator, and is used to generate standard continuous wave sinusoidal signals, noise signals, arbitrary digital waveforms, and delay of emission signal transcripts. When a polarization radar works in a calibrating mode, an output end of an emitter is used to couple a few of signals, which are used as transcripts of the emission signals. The signals are converted into digital signals after down conversion operation, filtering operation, and ADC conversion operation, and are used as digitalized emission sampling signals, which are input in the digital calibrating unit. After the amplitude conversion processing, the phase conversion processing, the frequency spectrum conversion processing, the delay conversion processing, and other conversion processing of the signals in a numerical field, the signals are converted into analog signals, and the analog signals are converted into radio frequency signals by up conversion operation, and then are irradiated on a main feed source by the calibrating horn.

Description

technical field [0001] The invention is applied in the technical field of dual-polarization weather radar, and the method can be used to calibrate the state and characteristics of any polarized wave in real time, thereby improving the measurement accuracy of the polarized radar. Background technique [0002] The main application of polarimetric radar is target recognition, and its technical basis is the measurement of the polarization characteristics of the target by radar, including the analysis and measurement of the target polarization scattering matrix and electromagnetic wave polarization parameters. With the successful application of dual-polarization radar in meteorological detection and meteorological particle identification, dual-polarization radar has gained wide recognition and application prospects in the field of meteorological particle (hail, haze, etc.) detection and artificial weather modification. [0003] In recent years, research and production institution...

AI Technical Summary

Problems solved by technology

However, the current domestically developed dual-polarization weather radars generally have the problem of poor polarization measurement accuracy, which leads to misjudgment of the shape of meteorological particles and affects the promotion and application of dual-polarization weather radars in China.

There are two main reasons for the error in polarization measurement. One is that the polarization purity of the emitted polarized wave is not enough.

Ferrite devices are generally used in China to adjust the phase and amplitude of radio frequency polarized waves. This technology is difficult to ensure the polarization characteristics of polarized waves, and is easily affected by factors such as temperature and environment.

Second, the stability of the radar system itself is not enough, and the consistency of the two channels is not enough

First, the analog system is susceptible to environmental temperature changes, and its attenuation cannot be accurately controlled, especially when the attenuation step i

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