A Laser System For Satellite Geodesy

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).

This book covers the entire field of satellite geodesy and is intended to serve as a textbook for advanced undergraduate and graduate students, as well as a reference for professionals and scientists in the fields of engineering and geosciences such as geodesy, surveying engineering, geomatics, geography, navigation, geophysics and oceanography. The text provides a systematic overview of fundamentals including reference systems, time, signal propagation and satellite orbits, together with observation methods such as satellite laser ranging, satellite altimetry, gravity field missions, very long baseline interferometry, Doppler techniques, and Global Navigation Satellite Systems (GNSS). Particular emphasis is given to positioning techniques, such as the NAVSTAR Global Positioning System (GPS), and to applications. Numerous examples are included which refer to recent results in the fields of global and regional control networks; gravity field modeling; Earth rotation and global reference frames; crustal motion monitoring; cadastral and engineering surveying; geoinformation systems; land, air, and marine navigation; marine and glacial geodesy; and photogrammetry and remote sensing. This book will be an indispensable source of information for all concerned with satellite geodesy and its applications, in particular for spatial referencing, geoinformation, navigation, geodynamics, and operational positioning.

The contribution of Satellite Laser Ranging (SLR) to the definition of the origin of the reference frame (geocenter coordinates), the global scale, and low degree coefficients of the Earth's gravity field is essential due to the remarkable orbit stability of geodetic satellites and the accuracy of laser observations at a level of a few millimeters. Considering these aspects, SLR has an exceptional potential in establishing global networks and deriving geodetic parameters of the supreme quality. SLR faces today the highest requirements of the Global Geodetic Observing System (GGOS) yielding 1 mm of long-term station coordinate and 0.1 mm/y of station velocity stability. The goal of this work is to assess the contribution of the latest models and corrections to the SLR-derived parameters, to enhance the quality and reliability of the SLR-derived products, and to propose a new approach of orbit parameterization for low orbiting geodetic satellites. The impact of orbit perturbations is studied in detail, including perturbing forces of gravitational origin (Earth's gravity field, ocean and atmosphere tides) and perturbing forces of non-gravitational origin (atmospheric drag, the Yarkovsky effect, albedo and Earth's infrared radiation pressure). A multi-satellite combined solution is obtained using SLR observations to LAGEOS-1, LAGEOS-2, Starlette, Stella, and AJISAI. The quality of the SLR-derived parameters from the combined solution is compared with external solutions. The Earth rotation parameters are compared to the IERS-08-C04 series and the GNSS-derived series, whereas the time variable Earth's gravity field coefficients are compared to the CHAMP and GRACE-derived results.

Contents: The use of artificial satellites for geodesy; Satellite and ground instrumentation; AFCRL laser-satellite geodesy; AFCRL geodetic dual laser system; Intervisible (geometric) adjustment theory; Short arc geodetic adjustment (SAGA) theory; Geometric results from geodetic satellite (ANNA 1B) optical data; Improvement of the GEOS-1 North American tracking network from multiple short arc geodetic adjustments; Near term prospects for positional accuracies of 0.1 to 1.0 meters from satellite geodesy; Results from simulations of continuously integrated doppler for precise aircraft positioning; Simultaneous recovery of satellite and station positions utilizing the short arc method; Least-squares collocation method for combination of satellite-derived gravitational and terrestrial gravity.