Design and Construction of an Infrared Laser Transmitter for a Compact Satellite Laser Ranging System

Abstract

Satellite Laser Ranging (SLR) is in use in different fields, like geodesy and space surveillance. Still, the coverage of SLR-Station around the globe is rather uneven. The demand for more SLR-Stations rises as a broader data base increasing data accuracy and thus improves the correctness of interpretations. However, setting up and running an SLR-Station implies high costs for the leading agencies, which arises from the need for a site for the station, on-site staff and especially high quality instrumentation like high energy laser systems. The technical approach though, enables novel set-up possibilities. Direct drive mounts with high angular velocity allow even fast tracking, a new generation of event-timers enables laser ranging at high repitition rates and small powerful lasers invent new options to place them in the system. The Institute of Technical Physics in Stuttgart exploits these new opportunities by building up a compact Satellite Laser Ranging System, called miniSLR, minimizing overall costs. The complete system should be contained in a 2 m x 2 m x 2 m box which is fully sealed and waterproof. The established laser with a pulse energy of 170 µJ is directly mounted onto the telescope mount. Therefore, the whole laser transmitter system is also placed directly on the mount. This limits the size of the transmitter system to a commercial aluminium breadboard of 60 cm x 50 cm. It is equipped with commercial optics and optomechanics, including important controlling and imaging components. A software written by the scientists at the Institute and also already integrated in other SLR systems will be used to control each unit and operate the miniSLR completely autonomously. The concept of the miniSLR has already achieved a paper presented at the "International Astronautical Congress" 2018 in Bremen, Germany. The paper is listed in the References, number [6]. The approach in designing and setting up the system's transmitter is described in this work.