Research on a forward-looking scanning imaging algorithm for a high-speed radar platform

The range and azimuth information of a target can be obtained after coherent pulse accumulation of the traditional multiframe stepped-frequency (SF) synthesis wideband echo and spectrum analysis, and high-resolution two-dimensional imaging of the target can be achieved. However, the accumulation of a certain number of pulses requires a long beam dwell time, which cannot meet real-time imaging requirements for high-speed radar moving platforms. To solve the above problems, a scanning imaging mode is proposed by combining forward-looking imaging and scanning imaging, and a target echo signal model with the structure of scanning stepped-frequency is constructed. The SF pulses are grouped and transmitted according to the scanning order, and the echo pulses are sorted and reorganised. After the timing compensation and range Doppler coupling compensation are completed, the target is located and projected. The proposed imaging mode can achieve high-resolution scanning forward-looking imaging and can basically attain an azimuth resolution of approximately 0.1 degrees within the forward-looking scanning range. This imaging mode has higher real-time performance and a larger target imaging range than the traditional methods. Moreover, the simulation results showed good performance via the scanning imaging method.