Abstract
Abstract. Interferometric synthetic aperture radar(InSAR), as a space geodetictechnology, had been testified a high potential means of earth observation providing a method fordigital elevation model (DEM) and surface deformation monitoring of high precision. However, the accuracy of the interferometric synthetic aperture radar is mainly limited by the effects of atmospheric water vapor. In order to effectively measure topography or surface deformations by synthetic aperture radar interferometry (InSAR), it is necessary to mitigate the effects of atmospheric water vapor on the interferometric signals. This paper analyzed the atmospheric effects on the interferogram quantitatively, and described a result of estimating Precipitable Water Vapor (PWV) from the the Medium Resolution Imaging Spectrometer (MERIS), Moderate Resolution Imaging Spectroradiometer (MODIS) and the ground-based GPS, compared the MERIS/MODIS PWV with the GPS PWV. Finally, a case study for mitigating atmospheric effects in interferogramusing with using the integration of MERIS and MODIS PWV overSouthern California is given. The result showed that such integration approach benefits removing or reducing the atmospheric phase contribution from the corresponding interferogram, the integrated Zenith Path Delay Difference Maps (ZPDDM) of MERIS and MODIS helps reduce the water vapor effects efficiently, the standard deviation (STD) of interferogram is improved by 23 % after the water vapor correction than the original interferogram.
Highlights
Interferometric Synthetic Aperture Radar (InSAR) is a potentially powerful technology fortopographic and ground surface deformation mapping due to its fine resolution, high measurement accuracy, all-weather and day-and-night imagingcapability.Rogers et al reported the first application of SAR in Earth-based observations of Venus, whileGrahamwas regarded as the first to apply an InSAR system to Earth topographic mapping
The comparison shows that the accuracy of the Medium Resolution Imaging Spectrometer (MERIS)/Moderate Resolution Imaging Spectroradiometer (MODIS) Precipitable Water Vapor (PWV) is testified by the GPSPWV inversed by the groundobservation, and the MERIS/MODIS PWV can be used to reduce the influence of interferogram
The standard deviation (STD) of interferogram is decreased from 1.35cm to 1.04cm after the water vapor correction, and the improvement of using MERI/MODIS is up to 23%
Summary
Interferometric Synthetic Aperture Radar (InSAR) is a potentially powerful technology fortopographic and ground surface deformation mapping due to its fine resolution, high measurement accuracy, all-weather and day-and-night imagingcapability.Rogers et al reported the first application of SAR in Earth-based observations of Venus, whileGrahamwas regarded as the first to apply an InSAR system to Earth topographic mapping. Li et al reported that, after calibrating their scale uncertainty using GPS data, two or more MODIS near IR water vapor fields can be adopted to produce Zenith Path Delay Difference Maps (ZPDDM) for InSAR atmospheric correction, and this was designated as the GPS/MODIS integrated water vapor correction model. Spatiotemporal comparisons showed agreement between MERIS and GPS water vapor products Application of both the GPS/MODIS integrated and the MERIS correction to ERS/ASAR data over the Los Angeles region showed that the order of water vapor effects on interferogram can be reduced from ~10 mm to ~5 mm after correction. With ENVISA-ASAR dataset we will compare the MERIS/MODIS PWV with the GPS PWV, and work with integration of MERIS and MODIS data to mitigate the atmospheric effects in SAR interferograms in order to improve the accuracy of displacement measurements
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
