Target characterization in 3D using infrared lidar

ABSTRACT We report examples of the use of a scanning tunable CO 2 laser lidar system in the 9-11 m region to construct images ofvegetation and rocks at ranges of up to 5 km from the instrument. Range information is combined with horizontal and verticaldistances to yield an image with three spatial dimensions simultaneous with the classification of target type. Objectclassification is made possible by the distinct spectral signatures of both natural and man-made objects. Several multivariatestatistical methods are used to illustrate the degree of discrimination possible among the natural variability of objects in bo thspectral shape and amplitude.Keywords: lidar, multispectral imaging, matched-filter analysis, vegetation mapping, target detection 1. INTRODUCTION Infrared remote sensing instruments have been developed and applied to many different applications involving imagery of theearth’s surface. 1 In principle, both passive instruments (detecting reflected or emitted light) and active instruments (usingreflected laser light) can provide such spatial and spectral information, but passive instruments are more widely used becauseof their greater simplicity. In this paper, we demonstrate an application of a multispectral lidar platform to mapping ofvegetation and rock. Active lidar imagery provides three spatial dimensions rather than two, simultaneously with theidentification of the physical target sampled by the laser. At longer wavelengths accessible by a CO