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1、機(jī)載MIMO雷達(dá)穩(wěn)健非均勻樣本選擇方法張永順,劉洋,劉漢偉,李志匯(空軍工程大學(xué)防空反導(dǎo)學(xué)院,陜西西安710051)摘要:針對(duì)雜波訓(xùn)練樣本中混入干擾目標(biāo),導(dǎo)致空時(shí)自適應(yīng)處理(Space-TimeAdaptiveProcessing,STAP)技術(shù)的雜波抑制性能下降問(wèn)題,提出一種基于目標(biāo)知識(shí)進(jìn)行局部稀疏恢復(fù)的穩(wěn)健訓(xùn)練樣本挑選方法。該方法利用先驗(yàn)知識(shí)確定待檢測(cè)單元中目標(biāo)區(qū)域,對(duì)整個(gè)角度-多普勒平面進(jìn)行遍歷,獲得稀疏超完備基。通過(guò)變換矩陣對(duì)超完備基中對(duì)應(yīng)的目標(biāo)區(qū)域進(jìn)行“挖空”處理,局部稀疏恢復(fù)出超分辨的雜波空時(shí)譜,獲得雜波協(xié)方差矩陣估計(jì)。結(jié)合
2、廣義內(nèi)積(GeneralizedInnerProduct,GIP)算法,實(shí)現(xiàn)非均勻訓(xùn)練樣本挑選的過(guò)程。與常規(guī)GIP方法相比,該方法對(duì)于不同干擾強(qiáng)度的訓(xùn)練樣本,均有良好的檢測(cè)效果。經(jīng)仿真驗(yàn)證,所提方法的檢驗(yàn)統(tǒng)計(jì)量之間區(qū)分度更加明顯,對(duì)于干擾樣本的挑選更加徹底,有效提高了STAP技術(shù)的目標(biāo)檢測(cè)性能。關(guān)鍵詞:空時(shí)自適應(yīng)處理;樣本挑選;多輸入多輸出雷達(dá);稀疏恢復(fù);廣義內(nèi)積中圖分類號(hào):TN957文獻(xiàn)標(biāo)志碼:文章編號(hào):Arobustnon-homogeneoustrainingsampledetectionmethodZHANGYongshun,L
3、IUYang,LIUHanwei,LIZhihui(AirandMissileDefenseCollege,AirForceEngineeringUniversity,Xi’an710051,China)Abstract:Oncecluttertrainingsamplesmixwithinterferingtargets,whichcausecluttersuppressionperformancebyspace-timeadaptiveprocessingdeclines.Inordertosolvetheproblem,arobu
4、sttrainingsamplesdetectionmethodbasedontargetknowledgeandpartlysparserecoveryisproposed.Firstly,theobjectregioninunittobedetectedislocked.ThenthesparsecompletebaseisgotbydiscretizingthewholeAngle-Dopplerplane.Afterthat,hollowoutthecorrespondingobjectregioninsparsecomplet
5、ebasebytransformationmatrixtoobtainthesuperresolutionclutterspace-timespectrum,whichhelpstoestimatethecluttercovariancematrix.Finally,themethodiscombinedwithgeneralizedinnerproductmethodtorealizenon-homogeneoustrainingsampledetection.ComparedwithGIPmethod,themethodpropos
6、edcandetectinterferingtargetsindifferentintensity.Simulationanalysesdemonstratetheteststatisticsofproposedmethodhaveexcellentdiscriminationvalidity,andcandrasticallyeliminateinterferingtargets,whichimprovesthetargetdetectionperformanceofSTAP.Keywords:space-timeadaptivepr
7、ocessing;sampledetection;MIMOradar;sparserecovery;generalizedinnerproduct5機(jī)載雷達(dá)在檢測(cè)地面目標(biāo)的過(guò)程中,不可避免地受到來(lái)自地物雜波以及有源干擾的影響,這使得目標(biāo)信號(hào)被淹沒(méi),雷達(dá)的信號(hào)檢測(cè)性能因此受限。多輸入多輸出雷達(dá)[1-2](MultipleInputMultipleOutput,MIMO)具有多發(fā)多收以及波形正交的特點(diǎn),天線規(guī)模上要遠(yuǎn)遠(yuǎn)小于相同規(guī)格的相控陣?yán)走_(dá),在一定程度上解決了機(jī)載雷達(dá)由于自身重量以及天線孔徑大小受限,需要犧牲系統(tǒng)檢測(cè)性能作為代價(jià)的問(wèn)題[3
8、]??諘r(shí)自適應(yīng)處理[4-6]技術(shù)有別于傳統(tǒng)意義上的空域以及時(shí)域?yàn)V波技術(shù),它可以在空時(shí)二維平面上,自適應(yīng)地形成濾波凹口。在STAP處理過(guò)程中,需要大量滿足獨(dú)立同分布(Independentidenticall