Impact of Motion Characteristics of Airborne Platforms on the Performance of Space Laser Communication Links

Abstract

When a platform carrying a space laser communication system moves through the atmosphere, the relative motion of the turret and the air produces fluctuations in the air density, which affects the beam propagation, and, hence, the laser communication performance. In this paper, we propose a performance analysis method for the space laser communication link to the airborne platform. By employing this method, which is based on a flow field simulation, we are able to determine the laser link’s communication performance curves for various flying situations. At an altitude of 5 km and a signal-to-noise ratio (SNR) of 10 dB for the laser communication link, the bit error rate (BER) under a flight speed of 0.4 Mach is 5.1×10−4. With each 0.1 Mach increase in speed, the BER decreases by approximately 6×10−5. If the flight speed is 0.8 Mach and the flight altitude increases from 5 km to 10 km, the BER decreases from 7.26×10−4 to 1.89×10−4, but the system becomes more sensitive to changes in flight speed. Under the same flight altitude conditions, the beam spot on the downwind side is more affected by airflow, resulting in a general increase in the BER by approximately one order of magnitude, compared to the upwind side.