一种在长时间序列SAR影像上提取稳定目标点的多级探测法  

A Multi-Step Detection Method for Extraction of Stable Pointwise Target in Long Temporal SAR Image Series

作　　者：卢丽君[1] 廖明生[1] 王腾[1] 田馨[1] 

机构地区：[1]武汉大学,测绘遥感信息工程国家重点实验室,湖北武汉430079

出　　处：《遥感学报》2008年第4期561-567,共7页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家863计划(编号:2006AA12Z123);国家自然科学基金项目(编号:60472039,40523005)

摘　　要：基于长时间序列上的差分雷达地表形变检测技术是近年来形变监测领域中一项重要的关键技术,而在长时间序列上稳定目标点的准确提取则是其中的一项重要环节,在此本文提出了一个有效的提取稳定目标点的多级探测方法。该方法以传统的振幅探测法为基础提取稳定目标点,同时针对振幅探测中稳定目标点的分布密度低、不均匀等问题,建立时间相干性计算模型,并利用目标点时间相干信息提取更多满足要求的稳定点目标。本文选用上海地区的26幅ERS-1/2 C波段SAR图像(1992—2000年获取)进行了目标点的提取实验,证实了该方法的有效性和可靠性。Spaceborne differential interferometric Synthetic Aperture Radar technology(D-InSAR) in long temporal series is an important technology in the land subsidence measurement,extraction of stable pointwise target is a critical procedure in long temporal D-InSAR processing chain.As we know,now the main two kinds of method have been proposed.One is amplitude method that can be performed to model the similar behaviors with phase dispersion with no resolution loss by means of a time series analysis of amplitude data.The other is based on coherence stability that can be computed in the stack of interferograms.The two methods have their own defects,the former requires a minimum of 30 images to detect the stable pointwise target precisely,the latter will directly lead to lower resolution than the original images.In this paper we introduce an optimized extraction method of stable pointwise target combining amplitude and coherence analysis.In this paper,amplitude detection method is first implemented and the number of stable pointwise targets is extracted.In the step,the data need to be radiometrically calibrated in order to ensure the images to be comparable.And the experiential threshold of amplitude dispersion is selected to extract stable pointwise targets.Aiming at solving problems of low density and ununiformity distribution of pointwise targets extracted by amplitude detection,a multi-step detection method is proposed.The multi-step detection method first uses amplitude detection,the proper threshold is selected to extract candidates of stable pointwise targets,which can ensure most of stable pointwise targets are included and greatly improve computation efficiency by the threshold.Further temporal coherence is utilized to extract the precise pointwise targets.In the step,the model of temporal coherence is established,and the partial atmosphere disturb and orbit error are removed by lowpass filters,sequentially the phase caused by the DEM error is estimated by a rough search of parameter space,the average effective pha

关 键 词：长时间序列 目标点提取 振幅探测 多级探测 时间相干性 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]