Limitation of laser satellite communication due to vibrations and atmospheric turbulences

Abstract EN

In this research, we analyze the effects of vibrations and the atmospheric on turbulence for a broadband laser satellite down link (BLSDL).

The use of optical radiation as a carrier between satellites and in satellite-to-ground links enables transmission using very narrow beam divergence angles.

Due to the narrow beam divergence angle and the large distance between the satellite and the ground station or any object the pointing is a complicated process.

Further complication results from vibration of the pointing system caused by fundamental mezchanisms : tracking noise created by the electro-optic tracker and vibrations caused by internal satellite mechanical mechanisms.

Additionally an in homogeneity in the temperature and pressure of the atmosphere leads to variations of the refractive index along the transmission path.

These variations of refractive index as well as introducing other external noise, pointing vibrations, can cause fluctuations in the intensity and the phase of the received signal leading to an increase in link error probability.

In this research, we develop a bit error probability (BEP) model that takes into account both pointing vibrations and turbulence-induced high amplitude fluctuations (i.e., signal intensity fading) in a regime in which the receiver aperture antenna (Do) is smaller than the turbulence coherence diameter (do), the results indicate that the satellite broad band laser down link with the receiver can achieve a BEP of 10-9 and data rate of lGbps with normalized pointing vibration of and turbulence with After reducing these limitation of laser satellites and compensates relatively most atmospheric error probabilities due to atmospheric turbaulences (BEPS) or variation of refractive index by using for ward feeding under fine tracking which designed to decrease the residual jitter influencies or by using directional laser beam or introducing feeding forward compensation method andadaptive techniques to reduce the effect of system vibrations.