Comparative Analysis of Co-Pol & Cross-Pol EOS-04 Data for Interferogram Generation to Access the Efficacy in Deformation Monitoring

Interferometric Synthetic Aperture Radar (InSAR) has emerged as a potent method for monitoring surface deformation of earth with applications ranging from monitoring sesmic activity to subsidence detection. Interferogram generation in Synthetic Aperture Radar (SAR) involves acquiring complex image pair of same target and fine co-registering them for pixel correspondence (1/100
^th
of pixel), forming interferometric pairs, noise filtering, flat-earth removal, and computing the phase difference. The unwrapped phase provides a detailed representation of ground movement for applications such as subsidence monitoring and terrain deformation analysis. This paper delves into the comparative analysis of InSAR interferogram generation using horizontally transmitted and horizontally received (HH) data versus horizontally transmitted and vertically received (HV) data of EOS-04 satellite. Our research establishes the superiority of HH data in this context, primarily attributable to the high coherence between image pairs of HH polarization. The improved coherence between HH (co-pol) image pairs minimizes phase decorrelation and result in minimal noise interference, hence yielding interferograms with distinct fringe patterns and reduced artifacts and thus facilitating a more accurate interpretation of surface deformation. Our approach is validated using EOS-04 Strip map (FRS-1) Single-Look Complex data pairs, acquired in both co-pol (HH) and Cross-pol (HV) interferometric mode over Mauna Loa Volcano, Hawaii Island. The inherent characteristics of HH polarization contribute to a more robust and precise interferogram generation process compared to HV data.