Target signatures for laser altimeters: an analysis.

The statistical characteristics of the received signal for short pulse laser altimeters are investigated. Expressions are derived for the mean and temporal covariances of the received pulse for a direct detection receiver. The effects of laser speckle, shot noise, and surface profile of the ground target are considered. The results are used to compute the means and variances of the total received energy, propagation delay, and rms width of the received pulse. These parameters are shown to be directly related to the statistics of the surface profile.