Horizontal plane trajectory optimization for threat avoidance and waypoint rendezvous

The authors present research results on a method to perform waypoint rendezvous in conjunction with multiple-threat avoidance with the horizontal plane trajectory optimization algorithm. A 737-300 aircraft performance model was used to study trajectory optimization with SP/HTO (singular perturbation/horizontal trajectory optimization). The cost function used by J.L. Vian and J.R. Moore (1989) was modified to include the cost of line-of-sight angle to the destination in order to generate more flyable trajectories through regions of multiple threat envelopes. Results are presented for several scenarios in which there are multiple threats and rendezvous points. The surface-to-air threat effectiveness envelope developed and used in these mission scenarios to generate optimal trajectories is discussed. It is shown that the addition of a cost of line-of-sight angle to the destination avoids a tendency of the trajectory to immediately return to the x-axis when no threats are present in the direct path to the target; instead the trajectory leads directly to the target and is a more desirable solution. The local approach to trajectory optimization is shown to be useful in short-range scenarios or in cases where there may be pop-up threats