Calibration of coherent lidar targets

Abstract

We determine the backscatter reflectance (more properly the bidirectional reflectance distribution function at a 45° angle of incidence and observation) for circularly polarized radiation of λ = 10.6 μm for 120-grit aluminum oxide sandcloth (1.5 × 10−2 sr−1) and 400-grit silicon carbide sandpaper (1.1 × 10−2 sr−1) with respect to sublimed flowers of sulfur (1.8 × 10−1 sr−1). The effect of range and the atmospheric effect of turbulence-induced beam wander are discussed for both rotating disks and linearly translated belts. The advantages of large slowly rotating disks for field calibrations are presented.