1. Great Lakes Region Height Modernization Consortium
Overview of :
PennDOT CORS & VRS / RTN
for
Great Lakes Region Height Modernization Consortium
Charles I. Harpster, Jr., CP, LSIT
Geodetic Surveys Manager
April 13, 2011

2. ENGINEERING DISTRICTS
ERIE
WARREN
McKEAN
SUSQUEHANNA 1
TIOGA
BRADFORD
POTTER
CRAWFORD
WAYNE 4
Oil City
FOREST
WYOMING
ELK
CAMERON
SULLIVAN
LACKAWANNA 2
LYCOMING
VENANGO
Dunmore
PIKE
MERCER
Montoursville 3
Dunmore
JEFFERSON
CLINTON
CLARION
Clearfield
LUZERNE
COLUMBIA
LAWRENCE
MONROE 10
MONTOUR
BUTLER
CLEARFIELD
UNION
CENTRE
CARBON
ARMSTRONG
SNYDER
NORTHUMBER-
LAND 5
BEAVER
NORTHAMPTON 11
INDIANA
MIFFLIN
SCHUYLKILL
LEHIGH
Allentown
ALLEGHENY
Indiana
BLAIR
JUNIATA
CAMBRIA
Hollidaysburg
Bridgeville
Bridgeville
PERRY
DAUPHIN
LEBANON
BERKS
Harrisburg
BUCKS
WESTMORELAND
HUNTINGDON
WASHINGTON 9
MONTGOMERY 12
CUMBERLAND 8 6
Uniontown
LANCASTER
PHILADELPHIA
SOMERSET
BEDFORD
King of Prussia
FULTON
FRANKLIN
GREENE
FAYETTE
ADAMS
YORK
CHESTER
DELAWARE
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 PennDOT Field Equipment
Pre 1996 = Conventional Survey Techniques
Wild T2 Theodolite
Zeiss Ni2 Automatic Level

5. GPS at PennDOT Field 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 PennDOT Field Equipment
2006 = PennDOT started purchase of GPS+GLONASS
Trimble R8 (GPS only) = 2003+
Trimble R8 GNSS (GPS+GLONASS) = 2006+

7. GPS at PennDOT CORS = National Coverage thru the National Geodetic Survey

8. GPS at PennDOT PennDOT 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. Currently 20 NGS CORS in PA from PennDOT
GPS at PennDOT CORS = PA Coverage - data access thru the NGS
Currently 20 NGS CORS in PA from PennDOT
(16 – GPS and 4 – GNSS)
+ 7 more NGS CORS from other state entities

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

12. GPS at PennDOT CORS = 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

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

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

19. Resources NGS CORS NGS OPUS (Online Positioning Users Service)
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)
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 ed to you within seconds / minutes!
OPUS-DB = publish your results into NGS’s database
NGS Federal Geospatial Summit
NGS Survey Control Database
PennDOT’s Photogrammetry Asset Management System (PAMS)
PennDOT’s Surveying & Mapping Manual (Pub. 122M)