PS InSAR技术在微小形变的监测中有着独特的优势,但同时受到数据量的严重制约。本文以形变速率稳定的怀来县城为实验区,利用15景ASAR数据,依据主影像选择和高程改正选取了三种略有差异的模型分别进行PS处理,并对形变提取中的相位解缠、基线改正和高程改正进行误差分析。结果表明,小数据集的相位解缠和高程改正在部分PS点上容易发生错误,但形变估计整体上能够正确反映实际情况。三个模型中MS(Multi-Reference Single Re-gression)模型得出结果最为可靠。小数据集解算的整体PS点质量不高,可以在满足PS点密度要求的前提下,降低相位标准偏差阈值以提高解算的可靠性。
A statistical analysis on the Wenchuan aftershock activity triggered by tidal forces is systematically studied based on Schusters test, including earthquakes triggered by tidal force, tidal stress and tidal coulomb failure stress. The results show that a group of strong aftershocks which occurred at the end of July to early August in 2008 at the north of Wenchuan were obviously triggered by earth tide, the same conclusion is drawn by Schusters smooth test of the tidal force, tidal stress and tidal coulomb failure stress. In addition, the Wenchuan aftershock activity is obviously triggered by fortnight tide. In the north, the aftershocks happened more frequently in the first and last quarters of the moon, and in the south, the aftershocks happened more frequently in the first and last quarters of the moon and during the full moon.
