利用合成孔径雷达干涉测量的短基线技术对汶川震前的地表形变进行面状监测。获取的是日本卫星L波段的ALOS PALSAR传感器拍摄的卫星数据。在Gamma软件处理下,将2007年6月至2008年5月的时隔320 d的6景数据,利用stacking技术得到汶川震中地区在震前一年内的变形速率。变形特征表明,沿着汶茂断裂带呈“凸”字形分布特征,断裂带处最大隆升值达24 cm,断层两侧出现下降的趋势,在绵虒镇附近达到最大沉降值22 cm。与前人用D-InSAR所做出的研究结果相比,二者具有很好的一致性。
In this paper, using the short baseline technique of synthetic aperture radar interferome, we try to monitor the ground deformation before Wenchuan earthquake. Under the gamma software, the deformation rate of Wenchuan epicentral area in one year before the earthquake was obtained by using stacking technique in June, 2008 and May, 2006. The deformation characteristics indicate that the maximum uplift value reaches 24 cm along the Wenmao fault zone and the two sides of the fault show a downward trend. The maximum sedimentation value reaches 22 cm in the vicinity of Mianyang Town. By comparing with the results of D-InSAR, the two are in good agreement. The trend of vertical deformation field before the earthquake may provide a scientific basis for earthquake prediction.