DOI: 10.3724/SP.J.1146.2013.00315

Journal of Electronics & Information Technology (电子与信息学报) 2013/35:12 PP.2829-2835

A Joint Method to Correct Ionospheric Phase Perturbation in Over-the-horizon Radar

Skywave Over-The-Horizon Radar (OTHR) can achieve long range detection via the ionosphere reflection. However, time-varying ionosphere and multipath effect will lead to serious clutter spectrum spread in long Coherent Integration Time (CIT). It increases difficulty degree of the detection of slow-speed targets. To deal with contaminated echo in the case of the two spreading Bragg peaks overlapping, an ionospheric contamination correction scheme based on Short Time MUSIC Transform (STMT) and improved Phase Gradient Autofocus (PGA) method is proposed. In the scheme, coarse estimation of ionospheric phase contamination can be obtained and compensated by using STMT transform, then an adaptive sliding window filter is utilized to extract the first order clutter (calibration signal). After that, the remanent ionospheric phase contamination can be estimated and compensated accurately by using improved PGA method. Theoretical analysis and simulation results show that the scheme has a good performance on correcting the situation of two spreading Bragg peaks overlapping.

Key words:Skywave Over-The-Horizon Radar (OTHR),Ionosphere phase contamination,Short Time MUSIC Transform (STMT),Phase Gradient Autofocus (PGA) method

ReleaseDate:2014-07-21 17:01:13