Novel method for acquisition and identification of satellites in a cluster for laser communication applications

Laser satellite communication is one of the most promising systems of communication outside the earth's atmosphere. The communication line of sight is achieved by steering a very narrow transmitter laser beam in the direction of the receiver satellite, while simultaneously directing the narrow field of view (FOV) receiver telescope in the transmitter satellite direction. In order to communicate efficiently, steering direction estimation methods, using a priori procedures such as acquisition and identification, are required. The acquisition procedure estimates the direction of a satellite while the identification procedure identifies the specific satellite within the flight formation cluster. We use an electro optic detector matrix, a bank of tunable band pass filters, envelope detectors and a decision unit in our proposed system. Each of the satellites transmits an optical beacon modulated with a different RF frequency. The mathematical model takes into consideration the noise, the signal, the Doppler shift and the field of view of the system of each satellite in the cluster. In this paper we develop an acquisition algorithm scheme of the system and a mathematical model of the probability of missing the satellite and of erroneous identification.