Multi-aspect imaging of gound moving target by a stationary wide-band radar

Abstract

An experiment for ground moving train (GMT) imaging at multi-aspect angles by a stationary wide-band radar is introduced. The radar works at Ka band which incorporates both frequency-stepped chirp signals (SFCSs) and frequency-stepped noise signals (SFNSs). The total bandwidth covered by 20 sub-signals is 2GHz, whose carrier frequencies are 100MHz stepped. Each sub-signal has 120MHz bandwidth and 5μs time duration. A GMT are imaged at ±17.5°, ±15.0°, ±12.5°, ±10.0°, ±7.5°, ±5.0°, ±2.5°, 0.0° angles (we should point out that these angles are just relative without accurate calibration). The Doppler spectra of different aspect angles are presented and analyzed, which are consistent with expectation. The images from SFCS and SFNS are presented and compared. It is shown that the SFNS images are generally comparable with that of SFCS, or even better at some angles, e.g. 0.0° and 17.5°. The anti-interference advantage of noise radar is well demonstrated because the imaging environment is quite complicated with a lot of multi scatterings occur between the target and the metal fence of the bridge where the train passed by.