Another environment monitoring activity of the hyperspectral program of the Canada Centre for Remote Sensing is the investigation of the potential of hyperspectral remote sensing for the identification of activities related to the production of uranium. In this study, CCRS is collaborating with the Canadian Nuclear Safety Commission (CNSC) in the Canadian Safeguards Support Program (CSSP) which supports the International Atomic Energy Agency (IAEA) in developing operational remote sensing methodologies that will help to enforce international regulations for nuclear safeguards.

This study attempts to identify spectrally mineral compounds in the ore, waste rock, or mine tailings that are associated with uranium mining. The surface mineralogy of the exposed areas at a mine site can be mapped using hyperspectral remote sensing which allows the spectral discrimination and identification of many minerals. The objective of this study is to determine if uranium containing minerals or mine tailings include spectrally distinct mineral compounds that distinguish uranium mining operations from other mining activities.

Endmember fraction images of the uranium and copper tailings. High fractions are shown in white and zero fractions in black. Their associated endmember spectra are shown. Both endmember spectra exhibit the shape of an iron oxide mineral with the strong iron absorption band in the 850 nm to 1000 nm range. larger image (165Kb)

Shown here are the results of the analysis of airborne hyperspectral Probe-1 data acquired on July 8, 1999 over the Pronto mine tailings site between Lake Huron and Elliot Lake, Ontario. The processing of these data include radiometric correction, surface reflectance retrieval, endmember selection and identification, constrained linear spectral unmixing analysis, and the production of an abundance map for each endmember. While two of the extracted endmembers correspond to uranium tailings and copper tailings, their discrimination is more likely to be related to different iron oxide content than to the presence of uranium compounds, because the concentration of uranium in these tailings is extremely low (< 0.1 % ).

In August 2000 this study was extended to the Key Lake mine site in northern Saskatchewan where high-grade uranium ore (21% average) from McArthur River mine is processed. SFSI-2 hyperspectral imagery covering the wavelength range 1220 to 2420 nm (Neville et al., 2001) were acquired over the Key Lake and Rabbit Lake sites. These data are being analysed using spectral unmixing techniques implemented on ISDAS.

Although the tailings at the Key Lake mine have an average uranium content of 0.3%, which is higher than the ore grade mined in the Elliot Lake area, this concentration may still be too low to detect uranium or its by-products directly using airborne, or indeed, laboratory spectra. Efforts are being focussed on the mapping of the surface mineralogy at and near the mine site, and the milling and processing facilities, including the tailings disposal facilities, in order to characterize a typical uranium mine site.

Results of the processing of these data shown here include the endmember spectra and the corresponding abundance images.

	Figure 1. Site map, RGB site image, and fraction images corresponding to end member spectra extracted from the scene and plotted in Fig.2. Dark red = 100%; Dark blue = 0%. larger image (169Kb)
Figure 2. End member spectra extracted from hyperspectral data for the image in Figure1. larger image (53Kb)

To learn more about the use of hyperspectral remote sensing for environmental monitoring purposes, please consult the following articles and papers:

Neville R. A., K. Staenz, J. Lévesque, C. Nadeau, Q. Truong, G. Borstad. Uranium Mine Detection Using an Airborne Imaging Spectrometer; Fifth International Airborne Remote Sensing Conference, San Francisco, California, 17-20 September, 2001.

Lévesque J., R. Neville, K. Staenz, Q. Truong. Preliminary Results on the Investigation of Hyperspectral Remote Sensing for the Identification of Uranium Mine Tailings; Proceedings of ISSSR'01, Québec City, Canada, 10-15 June, 2001 Abstract

Lévesque J., K. Staenz, and Szeredi T. The Impact of Spectral Band Characteristics on Unmixing of casi Data for Monitoring Mine Tailings Site Rehabilitation; Canadian Journal of Remote Sensing, Vol. 26, No 3, 2000, pp. 231-240 Abstract

Shang, J., J. Lévesque, K. Staenz, P. Howarth, B. Morris, L. Lanteigne. Investigating casi Responses to Different Levels of Tailing Oxidation: Inco Copper Cliff Tailings Area, Northern Ontario, Canada; Proceedings of the 22th Canadian Symposium on remote sensing, Victoria, BC, August 21-25, 2000, pp. 565-573 Abstract

Lévesque J., K. Staenz, J. Shang, R. Neville, P. Yearwood, V. Singhroy. Temporal Monitoring of Mine Tailings Revegetation Using Hyperspectral Data, Sudbury, Ontario; Thirteenth International Conference on Applied Geologic Remote Sensing, Vancouver, British Columbia, Canada, 1-3 March, 1999, pp. 21-28 Abstract

Shang J., J. Lévesque, P. Howarth, B. Morris, K. Staenz, P. Yearwood. Preliminary Investigation of Acid Mine Drainage Detection Using casi Data, Copper Cliff, Ontario, Canada; Fourth International Airborne Remote Sensing Conference and Exhibition / 21st Canadian Symposium on Remote Sensing, Ottawa, Ontario, Canada, 21-24 June, 1999, pp. 771-778 Abstract

Staenz K., R.A. Neville, J. Lévesque, T. Szeredi, V. Singhroy, G.A. Borstad, P. Hauff. Evaluation of casi and SFSI Hyperspectral Data for Environmental and Geological Applications - Two Case Studies;Z Canadian Journal of Remote Sensing, Vol. 25, No 3, 1999, pp. 311-322 Abstract

Lévesque J., T. Szeredi, K. Staenz, V. Singhroy. Spectral Band Selection from casi Data for Monitoring Mine Tailings Site Rehabilitation; 20th Canadian Symposium on Remote Sensing, Calgary, May 10-13, 1998, pp. 161-164 Abstract

Lévesque J., T. Szeredi, K. Staenz, V. Singhroy, D. Bolton. Spectral Unmixing for Monitoring Mine Tailings Site Rehabilitation, Copper Cliff Mine, Sudbury, Ontario; Twelfth International Conference and Workshops on Applied Geologic Remote Sensing, Denver, Colorado, 17-19 November, 1997, pp. 340-347 Abstract

Lévesque J., V. Singhroy, K. Staenz, D. Bolton. Site Characterization of Mine Tailings at the INCO Copper Cliff Tailings Impoundment Area Using casi Imagery; International Symposium, Geomatics in the Era of RADARSAT (GER'97), Ottawa, Canada, May 25-30, 1997 Abstract