Estimation of laser system pointing performance via statistics of the received signal

Strategic laser system are subject to residual pointing errors arising from such sources as mechanical vibrations, telescope dome turbulence, and atmospheric turbulence. Systems such as those fielded by the Imaging Branch of the Air Force Research Laboratory during the Floodbeam Experiments at Starfire Optical Range, Albuquerque, NM, have energy requirements that dictate that the beam profile at the target must be small. This result in a system where the pointing jitter and boresight represent a sizeable fraction of the beam width. Analysis of result from the first FLoodbeam Experiment suggested a relationship between the simple statistics of the total photon returns and the expected system pointing jitter. Monte Carlo analysis has identified a linear relationship between the simple statistics of total returns and the pointing jitter, and an ideal analytic solution has confirmed the result. The simple relationship requires a substantial number of shots and has a bias in the presence of boresight. A second approach advancing the linear relationship, and based on statistical (chi) 2 techniques, is presented which simultaneously estimates jitter and boresight. Data from both Floodbeam experiments is analyzed. The results are consistent with the consensus view of system pointing performance during the experiments.