National Geodetic Survey

OPUS Projects updateOPUS Projects updateNOAA’s National Geodetic SurveyNOAA’s National Geodetic Survey

geodesy.noaa.govgeodesy.noaa.gov

Rick FooteRick Foote

Rick.Foote@noaa.gov

2015 FGCS Meeting, Crystal City, VA1

OPUS Projects RTN validation

3

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)

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.

CORS Stations fixed in OPUS Projects AdjustmentCORS Stations fixed in OPUS Projects Adjustment

BREWPABHFTS5IDPNGOBSBURNORS2ORK5REDMCABL

OPUS Projects RTN validation

6

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.

From the NGS 10 Year Plan 2013-2023:

NGS RTN webinars:2014: http://www.ngs.noaa.gov/corbin/class_description/RTN_Best_Practices_0314.shtml2013: http://www.ngs.noaa.gov/corbin/class_description/RTN_Administration.shtml2015: See http://www.ngs.noaa.gov/corbin/calendar.shtml for future webinar

OPUS Projects RTN validation

7

Example: (Also CORS Station)Difference: 1.0 cm latitude 0.2 cm longitude

OPUS Projects RTN validation

8

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

OPUS Projects Data Sharing

9

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

OPUS Projects using Rapid Static

10

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

OPUS Projects Training

11

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.

OPUS Projects 122015-04-14

Questions &Discussion