The influence of operating laser wavelengths on Doppler effect in LEO Optical satellite constellation

Nowadays, free space researches are focused on increasing the link’s data transfer rate capacity. For this purpose, optical wavelengths are preferred over radio-frequency (RF) wavelengths as signal carriers to satisfy the high data transfer rate over huge distances since optical frequencies are greater than RF ones and a greater frequency implies better carrier capacity. Low earth orbit (LEO) satellite constellations with laser links are well suited to display a global broadband network. Since both LEO communicating satellites are in a continuous movement, the relative distance between them changes periodically. Doppler effect is detected on the received signal onboard terminal of the receiver satellite which shifts the characteristics of the received signal. In this paper, we study the influence of the operating wavelength on the Doppler effect in LEO inter-satellite laser links for full-time accessing inter-satellite links. The choice of the operating wavelength is an important task because Doppler wavelength shift is directly proportional to the operating wavelength. Results show that the lower laser operating wavelength the minimum Doppler wavelength shift appearance.