摘要

Low earth orbit satellite constellations using laser inter-satellite links are recognized to be capable to satisfy the increasing broadband communication demands. However, Doppler in inter-satellite laser communications can degrade the performance of the optical space network. It is crucial to study the Doppler performance on the high precision system. The expression of Doppler wavelength shift for multiple hops laser inter-satellite links is proposed in the paper. The calculation of Doppler wavelength shift in multiple hops ISL is studied with the consideration of location, motion and onboard characters of the satellites. Theoretical and numerical analysis show different routing way between two certain distant satellites will lead to different Doppler wavelength shift and signal transmitting time, and the variation of Doppler wavelength shift is mostly depend on the number of laser inter-satellite links hops; reasonable onboard time delay can augment signal transmitting time with little influence to the Doppler wavelength shift. It is hoped that the study can help the routing selection of the optical space network and system compensation.

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