1	OPUS The On-Line Positioning User Service Gerald L. Mader Neil D. Weston National Geodetic Survey Silver Spring, MD
2	Why do we need OPUS? Recognize most positioning done with GPS Want to provide fast, accurate, consistent, reliable access to NSRS CORS data alone does not ensure consistency OPUS NGS computers NGS software Standard parameterization Standard coordinates/velocities Your machine talks to our machine
3	Why do we need OPUS-GIS? Centimeter accuracy not appropriate for all objects Lower grade receivers can deliver usable results Recover kinematic traverses Consistent application to NSRS across accuracy spectrum
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6	"Over 29,000 OPUS users" Over 29,000 OPUS users Over 600,000 OPUS solutions cm – level accuracy Machines talk to machines – minimal human input
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8	What’s Missing ? Publish in NGS Data Base (OPUS-DB) Means to share OPUS results Publicly funded surveys à publicly available Streamlined method for metadata input Process Projects (OPUS-Projects) Simultaneous solutions for many stations, many days Network adjustment Project management Data management
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18	From the Field Point of View Observer submits all data to OPUS 1^st Data Submission Completes main page (antenna type & ARP hgt.) Selects options Enters project ID & sets profile All subsequent data submissions Needs only to enter email address and data Profile values fixed to email address
19	From the Project Managers Point of View Receives OPUS solution emails from all observers Monitor data collection Monitor data quality Data file management is provided Daily network solutions while project is still underway Near real time feedback to project personnel
20	OPUS-RS (Rapid Static) Became operational February 2007 Allows data spans as short as 15 min. Uses software developed at OSU providing rapid ambiguity resolution
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22	OPUS-GIS Accepts single frequency data Accepts kinematic data Differential range solution to CORS Kinematic trajectory report Static occupation report Shape files are coming
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26	OPUS-METADATA GPS solutions are very good at providing positions as a function of time, but … Need to know what was being positioned Metadata needs to be supplied by observer
27	"Now" Now Anyone with high-end GPS receiver can contribute to NGS Data Base cm level accuracy Future Anyone with low-end GPS receiver can contribute to GIS Data Base dm-m level accuracy
28	Things To Think About 1000’s of people with acceptable equipment Can contribute to data bases if means provided How to manage potential Army of Observers ?
29	Conclusion Position data bases are continuing process Stake-holders are contributors/beneficiaries OPUS-type systems enable contributions Leadership needed to: Define requirements Provide means for participation Management