The Digital Reception And Filtering Of Marine Radar IF Signal

At present, most of the marine radar and traffic control radar pulse non-coherent system, processing means are mostly using digital processing technology in the video section and display terminal, the target detection and moving target tracking performance are improved to some extent, enhanced display of radar information. However, due to the use of digital processing technology mainly in the video section of the radar echo information, the sea clutter suppression, increase of signal to noise ratio, ability to identify target characteristics has been limited.This paper discusses a general treatment program for marine radar IF signal digital reception and signal detection based on high-speed digital signal processing devices. It studies the marine radar IF signal frequency characteristics, mainly discusses digital reception and signal detection technology for marine radar IF signal, realizes the radar IF signal digital down-conversion reception and part of target feature extraction and signal detection in traditional analog radar signal processor, presents a lot of software simulation and hardware testing and theoretical analysis about the algorithm discussed.In the part of IF radar signal digital reception, it analysises the basic structure of the digital receiver, digital sampling theory of passband signals, digital down conversion algorithm for each module, and non-phase coherent radar signal characteristics, discusses co-simulation technology based on ISE/Modelsim/Matlab, gives the hardware implementation of digital down conversion-the realization of numerical control oscillator, digital mixer, digital filters and digital extraction.In the part of non-coherent radar signal detection, it mainly studies the problem of marine radar signal detection, and gives a specific FPGA implementations. The related technology can improve the performance of weak signal detection, through self-related operations, small signal overwhelmed by noises can be prominent, resolving the low SNR target detection problem; through the accumulation of sliding window, can effectively improve the radar echo signal to noise ratio, improving the sensitivity of the receiver; CFAR detector can maintain at a constant false alarm rate reduction under the conditions of background noise interference, providing adaptive decision threshold.