Shipborne Acquisition, Tracking, and Pointing Experimental Verifications towards Satellite-to-Sea Laser Communication

He He,Liu Liu,Zhou Zhou,Wang Wang,Qi Qi,Cao Cao,Gao Gao,Song Song,Zhang Zhang,Tan Tan,Huang Huang,Ren Ren

doi:10.3390/app9183940

Abstract

Acquisition, tracking, and pointing (ATP) is a key technology in free space laser communication that has a characteristically high precision. In this paper, we report the acquisition and tracking of low-Earth-orbit satellites using shipborne ATP and verify the feasibility of establishing optical links between laser communication satellites and ships in the future. In particular, we developed a shipborne ATP system for satellite-to-sea applications in laser communications. We also designed an acquisition strategy for satellite-to-sea laser communication. In addition, a method was proposed for improving shipborne ATP pointing error. We tracked some stars at sea, achieving a pointing accuracy of less than 180μrad.We then acquired and tracked some low-Earth-orbit satellites at sea, achieving a tracking accuracy of about 20μrad. The results achieved in this work experimentally demonstrate the feasibility of ATP in satellite-to-sea laser communications.

Highlights

Laser communication is a technology that uses a laser beam as a carrier to transmit information in space [1,2]
The is affected by sea waves, producing periodic yaw, pitch, and roll disturbances, which cause the andpointing pointing (ATP)’s line-of-sight axis to wobble a few three periodic yaw, pitch, andofroll cause the ATP's line-of-sight axis wobble a degrees
ATPsystem system(Figure (Figure6)6)mainly mainlytotoverify verifythe theability abilityfor foracquisition acquisitionand and pointing, a fast-steering mirror was not used at the fine pointing stage

Summary

Introduction

Laser communication is a technology that uses a laser beam as a carrier to transmit information in space [1,2]. The laser beam used in space laser communication is emitted at an angle that is near the diffraction limit. The divergence angle of very narrow communication beams requires both communicating sides to maintain extremely high dynamic alignment accuracy. With the ultimate aim of realizing a global-scale laser communication for practical use, many significant achievements have been made in the past decades, such as the demonstration of links for building-to-building communication [3,4], airborne applications [5,6,7], inter-satellite applications [8,9], satellite-to-ground [10,11,12,13,14,15,16], and ship-to-ship communication [17,18,19].

Methods

Results

Conclusion