Aerial remote sensing is useful for spotting indicators in the survey of mine-suspected areas and minefields. Because the detection of landmines in the soil and under the vegetation cover is not yet practical, the minefield indicators and their electromagnetic signatures provide means for detection of the mine-suspected areas and minefields. The minefield indicators can be natural (e.g., vegetation cover) over a large spatial extent, or else artificial or man-made (e.g., trenches, bunkers, demolished objects) over a small spatial extent. The dimensions of artificial minefield indicators require use of multi-spectral sensors and aerial images with spatial resolution below one meter. Due to a mixture of natural and artificial minefield indicators, aerial survey should provide wide-area coverage, with very high spatial and spectral resolution. Two different approaches were applied to resolve this conflict. One approach used very high spatial resolution sensors (in the range of five to 10 cm), four wavelengths (green [G], red [R], near infrared [NIR] and thermal infrared), and image acquisition at low heights above terrain (starting with 30 m). Due to a large number of images, a serious problem was mosaicking and fusing the images acquired by used sensors (spatial accuracy and matching the radiometry). Another approach used three different sensors: multispectral line scanner (12 channels), synthetic aperture radar (Experimental SAR, four wavelengths) and photogrammetric camera RMK (color infrared photography [CIR], [G], [R] and [NIR]). Both cases used digital sensors, while aerial photography was used in one of them, but only as an auxiliary source of ground truth and contextual information.
"Fusing Aerial Multispectral Imagery and High-Resolution Photography,"
Journal of Mine Action
: Vol. 8
, Article 45.
Available at: http://commons.lib.jmu.edu/cisr-journal/vol8/iss2/45