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developed a web-based service called OPUS (On-line Positioning User Service) to provide GPS users easier access to the country's National Spatial Reference System (NSRS). OPUS allows professionals in the fields of geodesy, surveying, mapping, and GIS to submit their GPS data files to NGS headquarters, via the web, where they are processed to determine(More)
The National Geodetic Survey (NGS) officially began public operation of the web-based On-line Positioning User Service (OPUS) in March 2001 as a means to provide GPS users easier access to the National Spatial Reference System (NSRS). Through OPUS, our goal is to provide the means to accurately, reliably, and quickly obtain consistent geodetic positions.(More)
We present what is, to our knowledge, the first demonstration of the application of the laser homodyne interferometric technique to the quantitative identification of individual trace molecular constituents of a binary mixture in an ambient atmospheric background. Operation of the laser interferometric detection system to within a factor of 26 of the(More)
SUMMARY This research is aimed at determining how and to what extent rover station coordinate accuracies, from the Online Positioning User Service (OPUS), at the National Geodetic Survey (NGS), are influenced by reference station spacing and rover station occupation times. The first phase of the experiment was to treat a large number of stations in the CORS(More)
Recently, a new set of 14 transformation parameters was jointly adopted by National Resources Canada (NRCan) and the U. Although a unique set of similarity transformation equations could be applied everywhere to transform positional coordinates between these two terrestrial frames, a more consistent set of NAD 83 coordinates can be obtained if, locally,(More)
OPUS Projects – A Web-based application to administer and process multi-day GPS campaign data. SUMMARY The National Geodetic Survey (NGS) has operated the Online Positioning User Service (OPUS) since March 2001, to provide end-users easy access to the National Spatial Reference System (NSRS) using GPS data. Due to the program's popularity and the continuing(More)
SUMMARY During the last year, a number of significant milestones related to terrestrial reference frames were achieved. One of the most notable changes took place on April 17, 2011, when the International GNSS Service (IGS) adopted the IGS08 reference frame, a frame defined by a subset of 232 geocentric stations from the International Terrestrial Reference(More)
Online Positioning User Seruice (OPUS) to prooide end-users with easy access to the l,IS National Spatinl Reference System (NSRS). This populnr web-based application proaides accurate, reliable and consistent geodetic coordinates with minimal LLSer input. A submitted GPS data file is usually processed rnithin n few minutes and the computed coordinates are(More)
The inverse transformation of coordinates, from Cartesian to curvilinear geodetic, or symbolically (x,y,z)-(l,j,h) has been extensively researched in the geodetic literature. However, published formulations require that the application must be deterministically implemented point-by-point individually. Recently, and thanks to GPS technology, scientists have(More)