Description And Operation Of A Satellite Laser System

A novel laser system designed and developed for satellite illumination is based on the use of two ruby lasers. It obtains range with a Q-switched laser and angular information by photographing satellite-reflected high-energy normal-mode laser pulses against stellar fields. The Q-switched laser system, operated in a controlled multipulse mode, is capable of up to 10 range measurements in a single pumping period. This increases confidence in the validity of the measurements especially since they are obtained in the presence of the high background noise that is encountered in daylight range measurements. The difference in satellite range within a 400-microsec time frame has been observed by means of the multipulse approach. (Author).

Because of the inherent high sensor resolution satellite laser ranging (SLR) has been developed into a widely used range measurement technology, today more than 30 observing stations all across the world are routinely tracking a large variety of satellites in order to determine their orbits with high resolution. Recently this concept was also adopted for high-precision time transfer activities, such as the T2L2 experiment on Jason 2 and the European Laser Time Transfer (ELT) for the International Space Station. With complex targets such as the ISS one has to comply with stringent laser eye safety requirements in order to ensure the health of the astronauts. At the same time laser safety for air traffic has to be secured.

State of the art resource covering key technologies and related theories of inter-satellite links Inter-Satellite Links Technology explores satellite networking as a growing topic in the field of communication technology, introducing the definition, types, and working frequency bands of inter-satellite links, discussing the number of orbital elements of the spacecraft motion state under two-body motion and their conversion relationship, and establishing the basic demand model for inter-satellite link network, chain topology model, and transmission protocol model. The book focuses on the analysis and introduction of the principles and error sources of microwave and laser inter-satellite ranging, including the basic composition, workflow, and constraints of the laser inter-satellite link, and related design principles of the inter-satellite laser transmitter and receivers. Later chapters also discuss theories and methods of acquisition, alignment, and tracking, the impact of alignment errors on performance, and inter-satellite link modulation and its implementation. Specific sample topics covered in Inter-Satellite Links Technology include: Pulse position modulation (PPM), Differential Pulse Position Modulation (DPPM), Digital Pulse Interval Modulation (DPIM), and Double-head pulse interval modulation (DH-PIM) Basic demand model of inter-satellite link network application, including basic configuration of constellations and inter-satellite transmission networks Inter-satellite ranging accuracy, principles of microwave inter-satellite ranging, and analysis of microwave ranging error sources Effect of tracking error on the beam distribution at the receiving end and influence of tracking and pointing error on communication error rate Inter-Satellite Links Technology serves a completely comprehensive resource on the subject and is a must-have reference for experts and scholars in aerospace, along with graduates and senior undergraduates in related programs of study.

This groundbreaking resource is the first book to offer you a thorough, practical treatment of laser space communications. The book focuses on the feasibility of laser space communication links between satellites, satellites and airborne platforms, and satellites and ground based stations to achieve worldwide connectivity. You get expert guidance on weather avoidance approaches and adaptive antenna subsystems that help mitigate the effects of turbulence. The book presents simplified, yet highly accurate, engineering expressions of complex mathematics of turbulence that provide you with numerical values in the links' signal power budget. Moreover, you find an entire chapter devoted to noise photons and their effect on the bit error rate. This comprehensive volume covers a wide range of critical topics you need to understand for your work in the field, from a discussion on laser vs. RF communications in space, basic design features of a laser transceiver, and configuration of inter-satellite communication links, to selection of ground station locations, 5th Generation Internet (5-GENIN), and signal modulation schemes. The book is supported with over 70 illustrations and more than 100 equations.

This new resource provides an insight into the physical principles of the device technology that underpins many laser-based military systems in one form or another. From this knowledge a deeper understanding of the fundamental requirements and the potential performance, as well as limitations of such systems may be assessed, given the appropriate operational parameters. Engineers and students are provided with practical advice on how to evaluate laser devices and systems, operate them safely, and train with them.