DOI: 10.3724/SP.J.1146.2013.00239

Journal of Electronics & Information Technology (电子与信息学报) 2013/35:12 PP.2850-2856

Modified Chirp Scaling Imaging Algorithm Based on Range Walk Removal

In this paper, the effects on signal characteristic which caused by cubic range migration in high squint mode are considered, and a modified chirp scaling imaging algorithm is proposed. In this method, range walk is removed in time domain firstly, and range cell migrations of all targets in the imaging scene are corrected accurately by chirp scaling operation and the unified Range Cell Migration Correction (RCMC). Finally, a focused SAR image can be obtained after the modified azimuth filtering. The overall imaging procedure of the algorithm only involves fast Fourier transform and complex multiplication, which means higher efficiency. Simulation results show that the modified algorithm can greatly improve the azimuth side-lobe performance, which is a great advantage in the high resolution imaging in high squint mode.

Key words:SAR,Range-walk removal,Chirp Scaling (CS) imaging algorithm,Large squint angle

ReleaseDate:2014-07-21 17:04:40