1. National Geodetic Survey NOAA’s National Geodetic Survey
OPUS Projects update
NOAA’s National Geodetic Survey
geodesy.noaa.gov
Rick Foote
2015 FGCS Meeting, Crystal City, VA

2. Real-Time Networks aligned with the NSRS using OP
Oregon (ORGN) ~93 stations
Iowa (laRTN) ~98 stations
New York (NYSnet) ~63 stations
Utah (TurnGPS) ~73 stations
Minnesota (MnCORS) ~136 stations
and many more.
NGS NSRS validation still
developing…
(NOS 2015 Milestone)

3. OPUS Projects RTN validation
Mark Armstrong’s slide #11 showed that many RTNs are aligned with the NSRS, using the NGS RTN Guidelines for Real Time GNSS Networks document. As an example, two slides from the July 2013 RTN webinar presentation are shown next (with permission of Ken Bays, the ODOT RTN Manager)

4. Major Elements of ODOT’s Plan
Goal: Minimum of 10% of the stations in the ORGN will be NGS CORS; actually 15% of ORGN sites are NGS CORS
Process/Adjust with NGS OPUS Projects online
Process 5 days of data collected during a period of high barometric pressure over the NW United States
Fixed control in the OPUS-Projects:
NGS multi-year CORS sites that have “computed velocities” (minimum 2 ½ years data)
AND
Have long term antenna mount and location stability.
Float NGS CORS sites with “modeled velocities”
Overall Goal: compatibility with the NSRS and with existing and planned neighboring RTNs.

5. CORS Stations fixed in OPUS Projects Adjustment
BREW
PABH
FTS5
IDPN
GOBS
BURN
ORS2
ORK5
REDM
CABL

6. OPUS Projects RTN validation
From the NGS 10 Year Plan :
Goal 3 (of 5): Expand the National Spatial Reference System Stakeholder Base through Partnerships, Education, and Outreach
Objective 3-1: By 2015, provide a process for RTN operators to validate their RTNs are aligned to the NSRS and meet NGS’ acceptable standards.
With RTN use expected to grow, it would be wise to engage the RTN user community in the development of a methodology for understanding how their derived coordinates are consistent with the NSRS.
NGS RTN webinars:
2014:
2013:
2015: See for future webinar

7. OPUS Projects RTN validation
Example: (Also CORS Station)
Difference: 1.0 cm latitude
0.2 cm longitude

8. OPUS Projects RTN validation
Initial NGS RTN validation may show table of C-O values
Future NGS RTN validation may show daily plots of how well OPUS Projects derived positions agree with RTN manager’s positions

9. OPUS Projects Data Sharing
Another idea under consideration is having user selected OPUS Projects marks ability to be integrated into OPUS Sharing
Nearly 10,000 marks have been submitted to OPUS for sharing

10. OPUS Projects using Rapid Static
OPUS Projects uses OPUS-S only, which requires 2+ hours of data . OPUS-RS requires 15+ minutes of data, and studies have shown that longer OPUS-RS occupations are as accurate as OPUS-S. We are considering allowing one plus hour OPUS-RS occupations in OPUS Projects

11. OPUS Projects Training
OPUS Projects requires users to attend a 1 ½ day training class, usually led by State Advisors. Having hands on experience in selecting CORS, constraints, and the manner in which the network is set up is critical in the accuracy of the adjusted coordinates.
However, this requires considerable expense for NGS and time commitment for the trainers and the attendees. NGS will have future discussions into the possibility of creating a web based self paced course to instruct some users.

12. Questions & Discussion New Developments for OPUS
The OPUS gateway page is found at
OPUS Projects