西安电子科技大学学报(自然科学版)
西安電子科技大學學報(自然科學版)
서안전자과기대학학보(자연과학판)
Journal of Xidian University (Natural Science)
2015年
5期
55-62
,共8页
解虎%冯大政%虞泓波%袁明冬%聂卫科
解虎%馮大政%虞泓波%袁明鼕%聶衛科
해호%풍대정%우홍파%원명동%섭위과
稀疏表示%非均匀杂波%协方差矩阵估计%机载雷达%基于先验知识的空时自适应算法%参数估计
稀疏錶示%非均勻雜波%協方差矩陣估計%機載雷達%基于先驗知識的空時自適應算法%參數估計
희소표시%비균균잡파%협방차구진고계%궤재뢰체%기우선험지식적공시자괄응산법%삼수고계
sparse representation%heterogeneous clutter%clutter covariance matrix estimation%airborne radar%knowledge-aided STAP ( KA-STAP)%parameters estimation
在非均匀杂波环境下,空时自适应处理的关键在于如何利用少量样本准确地估计杂波协方差矩阵。基于稀疏表示的杂波协方差矩阵估计方法,仅利用单个或少量样本即可达到较好的杂波协方差矩阵估计效果,明显地提高了空时自适应算法的收敛速度。该方法利用杂波谱的稀疏性,根据稀疏表示理论估计出杂波功率谱,进而估计出杂波协方差矩阵。然而,采用稀疏表示方法估计所得的杂波谱常出现伪峰,容易造成杂波协方差矩阵估计偏差,故利用杂波谱分布的特殊空时耦合性,采用杂波脊曲线拟合方法剔除杂波谱中的伪峰,有效地提高了杂波协方差矩阵估计精度。另外,这种算法还可以对载机飞行参数(载机速度,偏航角等)进行估计。
在非均勻雜波環境下,空時自適應處理的關鍵在于如何利用少量樣本準確地估計雜波協方差矩陣。基于稀疏錶示的雜波協方差矩陣估計方法,僅利用單箇或少量樣本即可達到較好的雜波協方差矩陣估計效果,明顯地提高瞭空時自適應算法的收斂速度。該方法利用雜波譜的稀疏性,根據稀疏錶示理論估計齣雜波功率譜,進而估計齣雜波協方差矩陣。然而,採用稀疏錶示方法估計所得的雜波譜常齣現偽峰,容易造成雜波協方差矩陣估計偏差,故利用雜波譜分佈的特殊空時耦閤性,採用雜波脊麯線擬閤方法剔除雜波譜中的偽峰,有效地提高瞭雜波協方差矩陣估計精度。另外,這種算法還可以對載機飛行參數(載機速度,偏航角等)進行估計。
재비균균잡파배경하,공시자괄응처리적관건재우여하이용소량양본준학지고계잡파협방차구진。기우희소표시적잡파협방차구진고계방법,부이용단개혹소량양본즉가체도교호적잡파협방차구진고계효과,명현지제고료공시자괄응산법적수렴속도。해방법이용잡파보적희소성,근거희소표시이론고계출잡파공솔보,진이고계출잡파협방차구진。연이,채용희소표시방법고계소득적잡파보상출현위봉,용역조성잡파협방차구진고계편차,고이용잡파보분포적특수공시우합성,채용잡파척곡선의합방법척제잡파보중적위봉,유효지제고료잡파협방차구진고계정도。령외,저충산법환가이대재궤비행삼수(재궤속도,편항각등)진행고계。
One of the key problems of space‐time adaptive processing ( STAP) is how to estimate the clutter covariance matrix (CCM) accurately with a small number of samples when the clutter environment is heterogeneous . The CCM estimation methods based on sparse representation (CCM‐SR) can achieve a good estimation performance with only one or a few samples , which significantly improves the convergence rate of the STAP . By using the sparsity characteristic of the clutter spectrum , the CCM‐SR method estimates the clutter spectrum and yields a good estimation of the CCM . However , there are often many pseudo‐peaks in the clutter spectrum estimated by the sparse representation ( SR) , which will cause a CCM estimation error . By exploiting the special relationship of the clutter ridge curve between space domain and Doppler domain , we can eliminate the pseudo‐peaks in the clutter spectrum effectively via fitting the curve of the clutter ridge and improve the estimation accuracy of the CCM . In addition , a byproduct of our method is the estimation of the flying parameters ( the velocity of the radar platform , the crab angle and so on ) . Experimental results show that the proposed method can improve the performance of conventional STAP based on sparse representation (STAP‐SR) and obtain a good estimation of the flight parameters .