遥感学报
遙感學報
요감학보
JOURNAL OF REMOTE SENSING
2009年
1期
145-151
,共7页
吴宏安%张红%王超%汤益先%吴涛
吳宏安%張紅%王超%湯益先%吳濤
오굉안%장홍%왕초%탕익선%오도
InSAR%SRTM DEM%相位解缠%高程重建
InSAR%SRTM DEM%相位解纏%高程重建
InSAR%SRTM DEM%상위해전%고정중건
InSAR%SRTM DEM%Phase unwrapping%Topographic height reconstruction
山体的叠掩和阴影现象造成的信号去相关,一直是InSAR重建山区地表高程的瓶颈之一.为此,提出了一种新的基于粗分辨率SRTM DEM(约90m分辨率)辅助InSAR数据重建山区地表高程的方法.利用SRTM DEM模拟的干涉相位,对ERS-1/2干涉相位做去地形相位处理,得到残余相位.通过对解缠后的残余相位计算方差提取叠掩和阴影区域的噪声,并用平均相位近似恢复噪声区域的相位,然后将其转换为高程,并用SRTM DEM作高程补偿处理,从而实现地表高程重建.最后,定量比较了该方法与传统InSAR技术生成的DEM精度.实验表明,这种方法能有效提高传统InSAR技术生成地表高程的精度,这对提高星载雷达数据的使用效率具有重要意义.
山體的疊掩和陰影現象造成的信號去相關,一直是InSAR重建山區地錶高程的瓶頸之一.為此,提齣瞭一種新的基于粗分辨率SRTM DEM(約90m分辨率)輔助InSAR數據重建山區地錶高程的方法.利用SRTM DEM模擬的榦涉相位,對ERS-1/2榦涉相位做去地形相位處理,得到殘餘相位.通過對解纏後的殘餘相位計算方差提取疊掩和陰影區域的譟聲,併用平均相位近似恢複譟聲區域的相位,然後將其轉換為高程,併用SRTM DEM作高程補償處理,從而實現地錶高程重建.最後,定量比較瞭該方法與傳統InSAR技術生成的DEM精度.實驗錶明,這種方法能有效提高傳統InSAR技術生成地錶高程的精度,這對提高星載雷達數據的使用效率具有重要意義.
산체적첩엄화음영현상조성적신호거상관,일직시InSAR중건산구지표고정적병경지일.위차,제출료일충신적기우조분변솔SRTM DEM(약90m분변솔)보조InSAR수거중건산구지표고정적방법.이용SRTM DEM모의적간섭상위,대ERS-1/2간섭상위주거지형상위처리,득도잔여상위.통과대해전후적잔여상위계산방차제취첩엄화음영구역적조성,병용평균상위근사회복조성구역적상위,연후장기전환위고정,병용SRTM DEM작고정보상처리,종이실현지표고정중건.최후,정량비교료해방법여전통InSAR기술생성적DEM정도.실험표명,저충방법능유효제고전통InSAR기술생성지표고정적정도,저대제고성재뢰체수거적사용효솔구유중요의의.
Synthetic Aperture Radar Interferometric(InSAR)processing depends on phase unwrapping to convert phase to topographic height.However,in rugged terrain the signal decorrelation caused by layover and shadow is one of the limitations for InSAR topographic height reconstruction,because the phase unwrapping is difficult.A new algorithm is proposed in this paper to reconstruct high resolution digital elevation model(DEM)with the help of existing coarse SRTM DEM(about 90m×90m).Firstly,the simulated phase from coarse DEM is removed from the ERS-1/2interferogram.Thus the residual interferogram is easier for phase unwrapping.By calculating the variance of unwrapped residual interferogram,a proper threshold is selected to extract the noise phase of layover and shadow,and then the noise area are substituted by surrounding average phase to recover the phase approximately.After converting the residual phase to height.SRTM DEM is added to reconstruct the topographic height.The result shows that this method can not only solve the problem of phase unwrapping for layover and shadow in rugged terrain.but also improve the height accuracy and topographic detail feature of coarse resolution DEM.