Development of InSAR Neutral Atmospheric Delay Correction Model by Use of GNSS ZTD and Its Horizontal Gradient

Interferometric Synthetic Aperture Radar (InSAR) often suffers from atmospheric disturbances due to the microwave propagation delay effect, which limits surface displacement detection accuracy an order of centimeters or more. Here I developed a new neutral correction model for InSAR by using global navigation satellite system (GNSS) zenith total (ZTD) and its horizontal gradient data. The proposed at first retrieves regularly gridded ZTD distribution sea level linear height dependence GNSS observations least squares method. Then, is projected onto coordinate correct delay. evaluated performance applying it L-band ALOS-2/PALSAR-2 ScanSAR interferograms over Kanto plain in Japan. result showed that phase standard deviation decreased 33.87 % on average. By comparing with generic online service (GACOS) Japanese regional mesoscale weather (MSM), GNSS-based outperformed others my test case. sensitivity indicated including could improve reproducibility under situations fewer available stations. Although model’s applicability depends number stations area interest, has potential effectively mitigate ability smallamplitude displacements.