An Algorithm for Calculating Access Time Windows of Spot Targets Based on Space Geometry Model

STK software is usually used to calculate access time windows for observing spot targets in aerospace, but it's difficult to develop some applications based on STK. In this paper, we present a novel algorithm for calculating roll angles and access time windows of spot targets based on space geometry model. The algorithm can quickly check the visibility of spot targets, and get roll angles and access time windows if they are visible. Experimental results show that the algorithm is effective.