Radio-frequency interference suppression method of high-frequency ground wave radar

Abstract

The invention relates to the field of radar signal processing, in particular to a radio-frequency interference suppression method of a high-frequency ground wave radar. According to the method, on the basis of original high-frequency ground wave radar signal processing, an empirical mode decomposition method is used for decomposing received signals to obtain a plurality of intrinsic mode functions, radio-frequency interference positions are detected through standard deviation and sliding window processing, power spectrum judgment and instantaneous frequency judgment are conducted on sampling points of the radio-frequency interference positions of the intrinsic mode functions, and the amplitude of the sampling points meeting requirements is set to be zero. According to the radio-frequency interference suppression method of the high-frequency ground wave radar, in actual data processing, the application effect is good, signals are not damaged while noise is reduced, the suppression effect is obvious, the radar detection range is expanded, and the radar detection accuracy is increased.

Description

Technical field [0001] The invention belongs to the field of radar signal processing, and particularly relates to a method for suppressing radio frequency interference of a high frequency ground wave radar. Background technique [0002] High-frequency ground wave radar is an important detection equipment that can continuously monitor the ocean environment in a large area. It mainly detects ocean dynamics parameters such as wind, waves, currents and tides on the ocean surface and low-altitude and low-speed moving targets on the sea surface. The total length of my country’s coastline exceeds 32,000 kilometers, so the high frequency ground wave radar is of great significance to the national economy and national defense construction. [0003] High-frequency ground wave radars generally work at 3-30MHz, and there will be a lot of radio frequency interference in this frequency band. Radio frequency interference mainly comes from the dense short-wave communication signals, broadcast statio...

AI Technical Summary

Problems solved by technology

(2) The time when the radio frequency interference is more serious generally occurs from 17:00 to 21:00 in the evening. At this time, due to the disappearance of the D layer of the ionosphere, the communication signals of short-wave radio stations, especially busy fishing boats, cannot be effectively shielded by the ionosphere. Enter the radar system and interfere with the normal operation of the radar

In the adaptive beamforming anti-jamming method, because it relies on a large phased antenna array, the system is more complicated, and it is not suitable for small-aperture wide-beam radars, so this method is rarely used

However, the anti-jamming methods based on the time-frequency domain characteristics of the signal, such as the detection-removal-recovery method based on transient interference and the interference signal subspace orthogonal projection method based on the interference distance distribution characteristics, all require the reception of radio frequency interference. The signal is filtered, so it will inevitably cause a certain degree of loss and distortion to the useful signal (such as the increase of the side lobe amplitude and the broadening of the main lobe), and when there are multiple disturbances, this effect will become more serious , the suppression effect is not good

Images