(InSAR礦區(qū)形變監(jiān)測(cè)的邊緣保持−Goldstein組合濾波方法)
摘 要: 介紹InSAR技術(shù)用于監(jiān)測(cè)礦區(qū)地表形變的干涉圖濾波方法，為避免對(duì)密集條紋強(qiáng)噪聲干涉圖重復(fù)進(jìn)行Goldstein等方法過度濾波而導(dǎo)致的條紋信息喪失，提出一種邊緣保持−Goldstein組合濾波方法。采用具有強(qiáng)條紋保持能力的邊緣保持濾波方法進(jìn)行濾波，根據(jù)其偽相干值及相位標(biāo)準(zhǔn)偏差改進(jìn)Goldstein方法的濾波因子，從而達(dá)到更有效濾波的目的。結(jié)果表明：邊緣保持−Goldstein組合濾波比單次Goldstein濾波殘差點(diǎn)改善率提高了 23.7%，邊緣保持指數(shù)高達(dá)0.74，效果優(yōu)于二次Goldstein濾波效果。此法結(jié)合頻域和空域?yàn)V波的優(yōu)點(diǎn)，對(duì)于高密度條紋強(qiáng)噪聲干涉圖不僅具有較強(qiáng)的噪聲控制能力，而且具有很強(qiáng)的條紋細(xì)節(jié)保持能力。
關(guān)鍵字: INSAR；礦區(qū)；干涉圖；偽相干值；邊緣保持；Goldstein濾波
（1. School of Earth Science and Info-physics , Central South University, Changsha 410083, China;
2. Key Laboratory of Precise Engineering Surveying and Deformation Hazard Monitoring of Hunan Province,
Changsha 410083, China;
3. Institute of Investigation and Surveying of Jiangmen City, Jiangmen 529040, China）
Abstract:The filters for InSAR interferograms used in monitoring mining area deformation were introduced. The edge-preserved Goldstein filter was presented in order to avoid the loss of fringe detail of InSAR interferograms with strong noise and dense fringes caused by over filtering when processed repeatedly by traditional methods such as Goldstein filter. The interferogram was filtered by edge-preservation filter with strong edge-preserving performance. The result was further smoothed by the improved Goldstein filer, whose filtering parameter was determined by pseudo-coherence and phase standard deviation derived from the result. The experiment results demonstrate that the new filter is 23.7% higher than that of once Goldstein filter in noise reduction while its edge preservation is 0.74, superior to twice Goldstein filter. This method performs well not only in noise reduction but also in detail preservation when applied to InSAR interferogram with strong noise and dense fringes.
Key words: InSAR; mining area; interferogram; pseudo-coherence; edge-preservation; Goldstein filter
