Review on strategies of space-based optical space situational awareness

Space-based optical(SBO) space surveillance has attracted widespread interest in the last two decades due to its considerable value in space situation awareness(SSA). SBO observation strategy, which is related to the performance of space surveillance, is the top-level design in SSA missions reviewed.The recognized real programs about SBO SAA proposed by the institutions in the U.S., Canada, Europe, etc., are summarized firstly, from which an insight of the development trend of SBO SAA can be obtained. According to the aim of the SBO SSA, the missions can be divided into general surveillance and space object tracking. Thus, there are two major categories for SBO SSA strategies. Existing general surveillance strategies for observing low earth orbit(LEO) objects and beyond-LEO objects are summarized and compared in terms of coverage rate, revisit time,visibility period, and image processing. Then, the SBO space object tracking strategies, which has experienced from tracking an object with a single satellite to tracking an object with multiple satellites cooperatively, are also summarized. Finally, this paper looks into the development trend in the future and points out several problems that challenges the SBO SSA.