Overview of : PennDOT CORS & VRS / RTN for Great Lakes Region Height Modernization Consortium Charles I. Harpster, J

1. Overview of : • PennDOT CORS & VRS / RTN • for • Great Lakes Region Height Modernization Consortium • Charles I. Harpster, Jr., CP, LSIT • (charpster@state.pa.us) • Geodetic Surveys Manager April 13, 2011

2. ERIE SUSQUEHANNA WARREN McKEAN 1 BRADFORD TIOGA POTTER CRAWFORD WAYNE 4 Oil City FOREST WYOMING ELK SULLIVAN LACKAWANNA CAMERON LYCOMING 2 VENANGO PIKE Dunmore 3 Dunmore Montoursville MERCER CLINTON JEFFERSON CLARION LUZERNE Clearfield COLUMBIA MONROE LAWRENCE MONTOUR 10 UNION CLEARFIELD BUTLER CENTRE CARBON 5 NORTHUMBER- LAND ARMSTRONG SNYDER NORTHAMPTON BEAVER INDIANA LEHIGH 11 SCHUYLKILL MIFFLIN Allentown BLAIR JUNIATA Indiana ALLEGHENY CAMBRIA Hollidaysburg BERKS DAUPHIN LEBANON PERRY Bridgeville Bridgeville Harrisburg BUCKS WESTMORELAND HUNTINGDON MONTGOMERY 9 6 WASHINGTON CUMBERLAND 12 8 Uniontown LANCASTER PHILADELPHIA SOMERSET King of Prussia BEDFORD FULTON FRANKLIN DELAWARE CHESTER FAYETTE YORK GREENE ADAMS • Our Purpose & Function: • Provide Geodetic Survey Operations & Support for the PennDOT Photogrammetry & Surveys Section & Districts • Provide Geodetic Survey Control for the Commonwealth • Coordinate with the National Geodetic Survey (NGS) ENGINEERING DISTRICTS

3. GPS at PennDOT

4. GPS at PennDOTField Equipment • Pre 1996 = Conventional Survey Techniques Wild T2 Theodolite Zeiss Ni2 Automatic Level

5. GPS at PennDOTField Equipment • 1996 = PennDOT purchased first GPS units for PSS • 1999 = PennDOT purchased GPS units for all Districts Trimble 4800 Rover 1999 Trimble 4000 SSI 1996 Trimble 4700 Base 1999

6. GPS at PennDOTField Equipment • 2006 = PennDOT started purchase of GPS+GLONASS Trimble R8 (GPS only) = 2003+ Trimble R8 GNSS (GPS+GLONASS) = 2006+

7. GPS at PennDOTCORS = National Coverage thru the National Geodetic Survey

8. GPS at PennDOTPennDOT CORS History First NGS CORS in PA from PennDOT WIL1 - in 1996 – at Penn State Univ, Wilkes-Barre Campus Trimble 4000SSI (now 4700) with Compact L1/L2 Antenna (still there!) Soon to be upgraded to Trimble NetR9 w/ Zephyr Antenna (GNSS)

9. GPS at PennDOT PennDOT CORS History First NGS (GNSS) CORS in PA from PennDOT PAAP – in 2010 – at Univ of Pittsburgh, Oakland Campus Trimble NetR5 w/ Zephyr Antenna (GNSS)

10. GPS at PennDOTCORS = PA Coverage - data access thru the NGS http://www.ngs.noaa.gov/CORS/ Currently 20 NGS CORS in PA from PennDOT (16 – GPS and 4 – GNSS) + 7 more NGS CORS from other state entities

11. GPS at PennDOTCORS = Examples – District 2-6 - Potter County GPS Antenna GPS Receiver with Computer

12. GPS at PennDOTCORS = Examples – District 10-0 HQ - Indiana Co GPS Antenna GPS Receiver with Computer

13. GPS at PennDOT VRS = Virtual Reference System

14. GPS at PennDOT VRS = Current PennDOT Use Current PennDOT use of VRS: • Increases field production by 30-50% from traditional GPS surveying • Reduce GPS field observation times by cellular phone link • Cut GPS field occupation time from 8-15 minutes to 3 minutes. • Reduce GPS office computation times by using real-time GPS methods • Coordinate values available in field, eliminates majority of GPS processing in office • More active field GPS units (rovers), eliminates static field GPS units (bases) • Significantly reduce need for “passive monumentation” • Anxiously awaiting newer / better NGS geoid models (NGS - 10 yr plan) • PennDOT currently has own VRS in SW PA • currently submitting purchase request for state-wide expansion of the PennDOT VRS • PennDOT PSS currently streams real-time data from 21 CORS to 3 Vendor RTN’s • 1 base station data stream to vendor = 1 field rover vendor account for PennDOT = No $$$ fees • Trimble & Topcon vendor networks & possibly Leica in the near future

15. GPS at PennDOT VRS = PennDOT Coverage – SW PA http://www.dotvrs.state.pa.us/

16. GPS at PennDOT VRS = Vendor (KeyNetGPS) PA Coverage http://vrs.keynetgps.com/

17. GPS at PennDOT VRS = Possible State-wide PennDOT Coverage http://www.dotvrs.state.pa.us/

18. GPS at PennDOT GPS Accuracies - Summary Method Obs Time Accuracy Static 30 - 60 min 0.02 - 0.05’ Horz (over 6 miles) 0.10 - 0.15’ Vert Fast Static 8 - 20 min 0.02 - 0.05’ Horz (under 6 miles) 0.10 - 0.15’ Vert RTK 5 sec - 3 min 0.05 – 0.07’ Horz (under 6 miles) 0.10 - 0.15’ Vert VRS 5 sec - 3 min 0.05 – 0.07’ Horz (in 20 mile network) 0.10 - 0.15’ Vert FUTURE Outlook = stronger GPS signals / more SVs = even better accuracy

19. Resources • NGS CORS • http://www.ngs.noaa.gov/CORS/ • Download GPS data to process against your GPS data (i.e. in TGO Software) • eliminates need for a field base receiver and frees up receiver for more roving production • NGS OPUS (Online Positioning Users Service) • http://www.ngs.noaa.gov/OPUS/ • Submit your GPS data to NGS and have them process it for you, for free! • Great for GPS positioning of single points, but points are not “networked or connected” together • OPUS-S (static) = at least 2 hrs of GPS data processed against 3 surrounding CORS • OPUS-RS (rapid-static) = 15 min to 4 hrs of GPS data processed against all surrounding CORS • Results emailed to you within seconds / minutes! • OPUS-DB = publish your results into NGS’s database • NGS Federal Geospatial Summit 2010 http://www.ngs.noaa.gov/2010Summit/2010FederalGeospatialSummitProceedings.pdf • NGS Survey Control Database • http://www.ngs.noaa.gov/cgi-bin/datasheet.prl • PennDOT’s Photogrammetry Asset Management System (PAMS) • http://www.penndotpams.org • PennDOT’s Surveying & Mapping Manual (Pub. 122M) • http://www.dot.state.pa.us/Internet/Bureaus/pdBOS.nsf/FormsAndPubsHomePage?OpenFrameSet