Tracking systems requirements for atmospheric steering compensation

The problem of pointing a transmitted laser from one airborne vehicle to another is examined. In the system concept, the transmitter is pointed out at the receiver by means of a tracking sensor that closes a tracking loop with a control system. The tracking sensor views a beacon on the receiving vehicle in close proximity to the receiver. For an airborne transmitting system, the power spectrum of the steering can have high-frequency components. It is shown that increasing laser transmitting apertures does not necessarily become cost effective in reducing the laser beam spreading and that reducing spreading by increasing tracking system bandwidth to track out atmospheric tilt provides limited payoff beyond certain limits. Actual transmitting system designs will require definition of the actual turbulence encountered for the scenario of interest.