An Improved Adaptive Median Filtering Algorithm for Radar Image Co-Channel Interference Suppression

Area of Science:

• Oceanography
• Signal Processing
• Radar Technology

Background:

• Co-channel interference in marine radar systems degrades the accuracy of radar image parameter extraction.
• Existing filtering methods struggle to effectively suppress this specific type of interference, impacting ocean monitoring capabilities.

Purpose of the Study:

• To propose an improved adaptive median filtering algorithm for suppressing marine radar co-channel interference.
• To enhance the accuracy of ocean monitoring by improving radar image parameter extraction.

Main Methods:

• A tangential interference ratio model was constructed using an improved Laplace operator to quantify co-channel interference.
• A threshold based on between-class variance was used to classify interference into high and low-ratio regions.
• An improved adaptive median filter processed high-ratio regions using sub-window medians, while low-ratio regions used current window medians.

Main Results:

• The proposed filtering algorithm demonstrated superior performance in suppressing co-channel interference compared to the standard adaptive median filtering algorithm.
• Validation using radar-measured data from Bohai Bay confirmed the algorithm's effectiveness.

Conclusions:

• The improved adaptive median filtering algorithm effectively suppresses marine radar co-channel interference.
• This advancement leads to more accurate ocean monitoring and radar image parameter extraction.