Abstract: Medium/long range air-to-air missiles usually adopt a combined guidance of midcourse and terminal. The target acquisition probability (TAP) for a missile in the takeover stage from midcourse to terminal phase is a key design parameter. In this article, a practical mathematical model for calculation of the target acquisition probability is built up, five main error sources which may have an impact on the TAP and their calculating formulas are studied, and the TAP calculation result for a typical missile trajectory is given. This method, by which the TAP can be obtained from a single trajectory calculation, is especially suitable to estimate impacts of various error sources on the TAP.

Key words: combined guidance, air-to-air missile, acquisition probability, mathematical models, error source