The infrared radiation characteristic of the missile is an important parameter for evaluating the penetration ability of a missile. Measuring the infrared radiation characteristic is important for us to distinguish a warhead from multiple objects and warn. Studying the infrared radiation characteristic of target has military value. The infrared radiation characteristic of target and atmosphere transmissibility of infrared radiation were analysed, and the way of enhancing the detecting ability of the ground-based LW infrared radiation measuring equipment was discussed.