[J09-5] Geodesy and seismology general contributions V

[J09-5-05] Two methods of three-dimensional surface deformation field derivation with the integration of InSAR and GNSS measurements

Haipeng Luo, ^○Ting Chen (School of Geodesy&Geomatics, Wuhan University,Wuhan,China)

Geodetic measurements play an important role in monitoring crustal deformation. Interferometric synthetic aperture radar (InSAR) measurements provide high-resolution surface deformation in satellite's Line of sight direction; whereas Global Positioning System (GPS) measurements record high-precision three-dimensional surface deformation at discrete stations. These two types of measurements could be integrated to monitor crustal deformation. Here we present two methods to derive three-dimensional surface displacement field from the integration of InSAR and GPS measurements: (1) ABIC method: a unified framework based on Akaike's Bayesian Information Criterion; and (2) ESISTEM method: an extended SISTEM(Simultaneous and Integrated Strain Tensor Estimation From Geodetic and Satellite Deformation Measurements) method. The former considers smoothness among surface deformation at neighboring pixels and there is no need to interpolate GNSS measurement into the same spatial resolution as InSAR measurements, which is commonly used in previous studies, avoiding the interpolation error. The latter is based on another strategy, named SISTEM method. In SISTEM method, only surrounding GPS measurements are used as constraints based on elastic theory; while in ESISTEM method, we extend the constraints by using both surrounding GPS and InSAR measurements.
We apply the ABIC and the ESISTEM methods into the derivation of three-dimensional surface deformation field associated with the 2008 Wenchuan earthquake and the 2015 Gorkha, Nepal earthquake, respectively.