Overhead Detection of Underground Nuclear Explosions by Multi-Spectral and Infrared Imaging

Abstract

The Comprehensive Test Ban Treaty (CTBT) permits Multi-Spectral and InfraRed Imaging (MSIR) to be performed as part of an On-Site Inspection (OSI) for the purpose of reducing the search area for the location of a possible underground nuclear explosion (UNE). Dedicated airborne MSIR measurements have not been made in conjunction with historical or recent UNE’s, so satellite data has been used to determine if there are MSIR observables associated with recent UNE’s. In this work MSIR data from commercial satellites has been used to show that there are detectable surface observables which can be used to greatly reduce the search area for the location of the UNE. This has been demonstrated using Landsat data of the Indian, Pakistani, and North Korean UNE’s in the last 12 years, and with GeoEye-1 data for the North Korean tests. The techniques used typically identify a region of interest less than 1 km2 in size (compared to the nominal 1,000 km2 search area), and the few false positives have been resolvable as such by using visible imagery. The results of this study show that MSIR data from satellites can be used to help prepare the inspection team for an OSI.