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Sponsored by the Geomatics Division of ASCE and the National Geodetic Survey of the U.S. National Oceanic and Atmospheric Administration.

CORS and OPUS for Engineers describes new global positioning system (GPS) technologies and procedures that are immediately relevant to civil engineering professionals engaged in high-accuracy positioning. This collection of 22 articles, half new and half previously published in peer-reviewed journals, assembles the latest thinking on the use of two advanced services-CORS and OPUS-for obtaining accurate positional coordinates. Created and managed under the auspices of the National Geodetic Survey, the CORS (continuously operating reference stations) network contains more than 1,600 permanent, geodetic-quality receivers that collect GPS data around the clock at locations distributed throughout the United States, its territories, and a few foreign countries. These data are then made freely available to the public via the Internet. OPUS (online positioning user service) is a free, automated, Web-based utility that provides its users with accurate and reliable positional coordinates in a timely fashion by processing each user's GPS data with corresponding data from the CORS network. Together, CORS and OPUS form the backbone of today's high-accuracy, three-dimensional positioning activities.

Both theoretical and empirical, this collection is a must-have for practitioners and researchers involved in surveying, GIS, remote sensing, and mapping applications that utilize GPS technology.