A Critical Analysis to Generate Change Detection Map using SAR Interferometry for Land Subsidence Monitoring of New Orleans City of USA.

Present paper aims to critically analyze and study the SAR interferometric RADARSAT data for deciding the specifications for land subsidence monitoring system for New Orleans city of USA using Differential SAR Interferometry (D-InSAR) approach. In Louisiana, areas along the coast are sinking as much as one inch a year, and the state loses approximately 35 square miles per year due to ground subsidence and coastal erosion (1). New Orleans is located in Southeastern Louisiana along the Mississippi River. This city is among the worst affected area due to land subsidence. Subsidence rate of New Orleans and its surrounding area is computed with on-the-ground measurements using man made reference points. Even though bench marks are carefully chosen, scientists doubt whether reference points are also sinking as well (1). Subsidence monitoring using satellite images especially SAR interferometry offers a viable alternative by which accurate surface deformations can be calculated. Synthetic Aperture Radar (SAR) is a coherent imaging technique capable of generating fine- resolution images of the scene. RADARSAT C-band images are generally unhindered by atmospheric conditions. SAR Interferometry, utilizing phase information also along with intensity, is capable of producing 3-D information about the scene. Repeat pass Interferometry makes use of SAR images of same scene acquired from the same position at different times and this helps in the measurement of small scale deformations of earth's surface. SAR/ SAR Interferometry, hence, offer a powerful mapping tool to measure deformation of earth at an unprecedented spatial details and accuracy.