A back-sunlight target is a target which comes out in the direction of the sun or which flies across the sun. When
the sun enters the field of view (FOV) of a conventional detecting system, the sun's intense radiation will saturate the
focal plane detector or may even damage it, so there exists solar-blind regions that conventional systems can not observe.
Therefore to track the sun and to detect back-sunlight targets is very important in military defense because the potential
of back-sunlight military targets, such as battle plane or missiles "coming out of the sun", cannot be avoided. A
resolution for sun tracking and back-sunlight target detecting is proposed here and its experimental system is designed
and tested. This system can be a useful supplement for conventional detecting systems.
The system consists of a sun capturer, a back-sunlight target detector, a two-dimension tracker, and a data
acquisition module. In order to detect and identify back-sunlight targets, the back-sunlight target detector has to stare at
the sun. This process comes in two steps. First the sun capturer searches and coarsely tracks the sun and then the
back-sunlight target detector finely tracks the sun and images it, while two dimensional motor gimbals are used as
mechanical tracker of the system. When any back-sunlight target is found, the data acquisition module will provide the
external processors with the information of the sun and the back-sunlight target for further processing.
The system's tracking accuracy of the sun is 0.006°, and the detecting resolution of back-sunlight targets is