Long-term airborne DInSAR measurements: P- and X-band cases

Recently, some experiments demonstrated that reliable DInSAR measurements can be achieved at any band and that further time-series analyses can be applied for airborne data. However, most of the airborne DInSAR results, including the time-series, published so far have focused on short-term analyses (baselines within hours or few days). This paper presents the first worldwide airborne DInSAR survey at P- and X-band for measuring the land movements occurred within 1 year and 3 months. The survey was performed by the OrbiSAR system of OrbiSat under contract with Petrobras (CENPES), as part of a experiment with the objective to identify possible threats to the pipeline due to land movements in Sao Sebastiao-SP, Brazil. The measurements at P-band show reliable and coherent movements in 80% of the imaged vegetated areas with accuracy in the order of centimeters. At X-band we were able to reliably measure coherent movements in urban areas with accuracy in the order of millimeters. Through field work evidences, the paper analyses the causes of these small scale land movements, and how they are related to geodynamic processes. A comparison between the DInSAR and in-loco inclinometer measurements is presented. The paper suggests some possible operational scenarios and discusses on the potential of the airborne DInSAR for land movement monitoring.