Abstract:

Taking the sixth underground nuclear test of North Korea as an example， based on the ascending and descending ALOS?2 SAR data， firstly， the line‐of‐sight deformation of the nuclear test site is obtained by D?InSAR technology， and the nuclear explosion parameters are determined by Bayesian inversion method. Then， the POT technology is introduced to measure the azimuth and range deformation of the nuclear test site. Finally， the D?InSAR and POT results are combined to calculate the three‐dimensional surface deformation field of the nuclear test site. This study found that the nuclear explosion was located beneath the Wanta Mountain at the Punggye‐ri test site in the Democratic People’s Republic of Korea. The longitude and latitude of the explosion are 129.079 2° east longitude and 41.302 6° north latitude， with a depth of approximately 550 m. The nuclear explosion resulted in a horizontal displacement of about 3 m and vertical subsidence of about 1 m. The results indicate that the significance of space‐based SAR remote sensing technology， especially long‐band SAR， in monitoring underground nuclear test， and it could offer new ideas for underground nuclear test monitoring.

Key words: underground nuclear test, InSAR, nuclear explosion parameter inversion, pixel offset tracking, three‐dimensional deformation field