CANADIAN SAFEGUARDS REMOTE SENSING PROGRAM HYPERSPECTRAL SURVEY

The Canadian Nuclear Safety Commission in collaboration with Canada Centre for Remote Sensing is engaged in a project using hyperspectral survey to identify those features of a typical uranium mine site which distinguish it from other types of mines. Hyperspectral survey is one major element of the Canadian Safeguards Remote Sensing Program which also includes Synthetic Aperture Radar airborne survey and commercial satellite imagery. The work is carried out in support of the International Atomic Energy Agency. Several flights have been carried out over Canadian nuclear facilities. The initial survey was carried out with Probe-1, over the Pronto uranium and copper mine tailings, and Blind River refinery in July 1999. These two facilities are located in the North shore of Lake Huron, Ontario, Canada. Subsequently, imagery of the Key Lake uranium mine site in Northern Saskatchewan was acquired in August 2000 with an airborne sensor package consisting of two imaging spectrometers: SFSI, which operates in the short-wave infrared part of the spectrum, and casi, which operates in the visible and near infrared. Coincident in situ spectral measurements were made using a portable field instrument for atmospheric correction of the airborne data and for calibration of the imaging spectrometer. The hyperspectral data were checked for spectral accuracy, and radiometric conversion factors were derived using the in situ spectral reflectance measurements of an extended target. Atmospheric corrections were performed. End member spectra were extracted automatically from the scene data using the Iterative Error Analysis method and the scene was spectrally unmixed using a linear constrained unmixing method. End member spectra are displayed and identified where possible. The main aim of the paper is to present some of the airborne results (while waiting for the availability of satellite borne hyperspectral data, e.g. from ORBVIEW-4) to illustrate the potential use of hyperspectral data and analysis techniques which could be used to extract useful information for environmental monitoring and safeguards applications such as detection and identification of substances which could be associated with a nuclear, or chemical, operation.