Triggered in part by the advent of high resolution commercial optical satellites, the analysis of open-source satellite imagery has now established itself as an important tool for monitoring nuclear activities throughout the world (Chitumbo et al 2001). Whereas detection of land cover and land use change is a commonplace application in remote sensing, the detection of anthropogenic changes associated with nuclear activities, whether declared or clandestine, presents a difficult challenge. It is necessary to discriminate subtle, often weak signals of interest on a background of irrelevant or uninteresting changes, see e.g. (Canty and Schlittenhardt 2001). In our contribution we focus attention on the use of conventional multispectral earth observation satellite platforms with moderate ground resolution (Landsat TM, ASTER, SPOT) to detect changes over wide areas which are relevant to nuclear non-proliferation and disarmament treaties. The analysis is based upon the multivariate alteration detection (MAD) algorithm proposed by Nielsen et al. 1998 with the inclusion of a recent refinement which puts weight on difficult observations (Nielsen to be published). The multispectral data are pre-processed by orthorectification, illumination angle correction, image registration to sub-pixel accuracy and, where appropriate, wavelet-based panchromatic sharpening. We illustrate the techniques with a number of case studies involving the location of underground nuclear explosions and detection of uranium mining sites. In the former case the change signals are compared with existing seismic data, which include explosion times, locations, yields and depths of burial as well as data about surface collapse (subsidence) phenomena like e.g. crater depth and diameter and test surface-collapse times. The work has been carried out within the framework of the Global Monitoring for Security and Stability Network of Excellence (GMOSS) initiated by the European Commission. Chitumbo, K., Robb, S., Bunney, J. and Lev\$\backslash\$'e, G., IAEA Satellite imagery and the Department of Safeguards, Proceedings of the Symposium on International Safeguards, Vienna 2001 IAEA-SM-367/16/08) on CD-ROM. Canty, M. J., Schlittenhardt, J., Locating the 1998 Indian nuclear tests, Eos, Transactions American Geophysical Union 82(3), 2001, pp. 25--29. Nielsen, A. A., Conradsen, K. and Simpson, J. J., Multivariate alteration detection (MAD) and MAF processing in multispectral, bitemporal image data: New approaches to change detection studies, Remote Sens. Environ. 64(1), 1998, pp. 1--19. Nielsen, A. A., Iteratively re-weighted multivariate alteration detection in multi- and hyperspectral data, to be published.
|Title of host publication||31st International Symposium on Remote Sensing of Environment, Global Monitoring for Sustainability and Security|
|Publication status||Published - 2005|