Atmospheric correction models for InSAR measurements

Wu, Y., Li, Z., Liu, J. and Xu, C. (2006) Atmospheric correction models for InSAR measurements. Geomatics and Information Science of Wuhan University (Chinese Version), 31(10), pp. 862-867.

Abstract

Repeat-pass Synthetic Aperture Radar Interferometry (InSAR) provides a new tool to map global topography with metre-scale accuracy and tens of metres spatial resolution, and its advanced differential technique (Differential InSAR, DInSAR) can be applied to detect surface displacement with sub-centimetre accuracy. A major source of error for repeat-pass InSAR is the phase delay (especially the part due to water vapour) in radio signal propagation through the atmosphere. In this paper, the latest development in InSAR atmospheric correction models is presented. In this paper, a brief review of atmospheric correction approaches, which have been proposed to reduce atmospheric effects (particularly water vapour effects) from SAR interferograms in the last decade, is given. Emphasis is given to GPS topography-dependent turbulence model (GTTM) and GPS/MODIS integrated water vapour correction models developed at University College London [Li et al., 2005b, 2005e]. An example over the Los Angeles region shows that, without InSAR atmospheric correction, the RMS difference between GPS-derived and InSAR-derived range changes in the line of sight (LOS) direction was 1.1 cm. After applying the GTTM or the GPS/MODIS integrated models, the RMS difference decreased to ~0.5 cm, suggesting that both correction models successfully reduced atmospheric water vapour effects on interferograms. It is also shown that the GTTM and GPS/MODIS integrated models are complementary when correcting InSAR measurements.

• Item Type: Articles
• Keywords: InSAR, MODIS, atmospheric effects, water vapour, deformation
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Li, Dr Zhenhong
• Authors: Wu, Y., Li, Z., Liu, J., and Xu, C.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences; G Geography. Anthropology. Recreation > GB Physical geography; T Technology > TA Engineering (General). Civil engineering (General)
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Geomatics and Information Science of Wuhan University (Chinese Version)
• ISSN: 1671-8860