实现目标自适应红外隐身的第一步是获取遮挡背景图像，这部分图像是观察者处于某一视点观察目标时，被目标所遮挡住的背景。而当观察者在不同的视点观察目标时，被目标所遮挡住的背景是不同的，目标与遮挡背景满足透视投影的关系。为求得目标与遮挡背景的关系，首先建立了三套坐标系，即目标本体坐标系、视点坐标系以及热像仪坐标系，然后通过推导三套坐标系之间的转换关系，建立了目标表面各点与热像仪获取背景图像点之间的对应模型，从而实现了遮挡背景的获取。最后通过实验对该模型进行了验证，结果表明：该模型能够正确获取不同视点下的遮挡背景，为工程应用奠定了基础。

The first step of self-adaptive infrared stealth is the obtention of occlusion background image, this image is a part of the background which is covered by the object when the observer observes this object somewhere. When observing the object in different viewpoints, the background that is covered by the object is different, the object and the occlusion background have a relation of perspective projection. For obtaining the relation between object and the occlusion background, three coordinate systems were established which consist of object′s body-fixed coordinates, viewpoint coordinates and thermal imager coordinates, then the corresponding model between the point on object and the point on the thermal image got by thermal imager was derived by coordinate transformation between these three coordinates. At last an experiment was carried out to verify the model, the result shows that the occlusion background is obtained in different viewpoints by this model. The model lays a foundation of practical engineering application.