基于GPS和NCEP FNL数据改正InSAR大气延迟的可行性分析

InSAR技术是近二十几年来迅速发展的极具应用价值的空间对地观测新技术,它具有监测精度高、范围大、成本低、空间连续覆盖等优点,为滑坡、泥石流等地质灾害监测提供了一种新型的监测方法。但由于地质灾害多发生在暴雨频发、地质地貌复杂的区域,特殊的地理位置与气候使得InSAR技术应用中受大气延迟的影响非常严重,导致InSAR图像错误解释。本文在全面回顾当前主流的几种改正InSAR大气延迟的方法在国内外滑坡监测中的应用现状和实例的基础上,分析这几种技术的优势及问题点,并结合最新技术进展提出了一种基于GPS和NCEP FNL数据改正InSAR大气延迟的新方法,详细推导了该方法处理的流程,结合实例进行了分析比较,证明了其可有效削弱InSAR干涉图中的残余大气延迟相位,进而提高InSAR监测精度的优点。

Feasibility analysis of InSAR atmospheric delay correction based on GPS observations and NCEP FNL data

Over last two decades, Interferometric Synthetic Aperture Radar （InSAR） has been widely used to monitor geological hazards due to its high precision, wide area coverage and low cost. However, InSAR suffers from the phase delay in radio signal propagation through the atmosphere, and it becomes worse during the geological hazards which always occur in complex geological hilly areas with heavy rainfall. Based on a detailed review of some main application studies so far in the world, the advantages and difficulties concerning the application of these skills to landslide monitoring are concluded. By using some new developments of monitoring technique, possible solutions for the existing problems to practical application of InSAR atmospheric delay correction based on GPS observations and NCEP FNL data are proposed. This paper introduces the principles and data processing method of this technique, associates with some examples proving the advantages of reducing the residual of InSAR atmospheric delay phase, so as to improve monitoring accuracy.