PennDOT Photogrammetry _ Surveys Section by yaofenji

VIEWS: 39 PAGES: 19

									                  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
             ERIE

                                WARREN               McKEAN                                                                           SUSQUEHANNA
                                                                                              TIOGA                BRADFORD
                                                                          POTTER
    CRAWFORD          1                                                                                                                                   WAYNE


                    Oil City     FOREST
                                                     ELK       CAMERON                                              SULLIVAN
                                                                                                                                  WYOMING        4
                                                                                                                                               LACKAWANNA
                                                                                                LYCOMING
                 VENANGO                                                                                                                         Dunmore
                                                                                                                                                 Dunmore           PIKE
    MERCER


                           CLARION
                                       JEFFERSON
                                                                      2            CLINTON
                                                                                              Montoursville
                                                                                                                   3
                                                      Clearfield                                                                  LUZERNE
                                                                                                                       COLUMBIA                          MONROE
  LAWRENCE
                                                                                                                   MONTOUR
                                                                                                       UNION
             BUTLER
                               10
                          ARMSTRONG
                                                    CLEARFIELD                 CENTRE

                                                                                                               NORTHUMBER-
                                                                                                                                            CARBON



  BEAVER
                                      INDIANA
                                                                                                  SNYDER       LAND

                                                                                                                         SCHUYLKILL
                                                                                                                                       5       LEHIGH
                                                                                                                                                        NORTHAMPTON


             11
       ALLEGHENY                     Indiana     CAMBRIA
                                                              BLAIR                                                                         Allentown
                                                           Hollidaysburg                                                               BERKS
                                                                                               PERRY       DAUPHIN     LEBANON
            Bridgeville
            Bridgeville                                                                                        Harrisburg                                     BUCKS
                       WESTMORELAND
                                                                      HUNTINGDON
                                                                                                                                                        MONTGOMERY
  WASHINGTON                                                                               CUMBERLAND

            12      Uniontown                              9                                                   8           LANCASTER              6                PHILADELPHIA
                                      SOMERSET
                                                      BEDFORD         FULTON    FRANKLIN                                                   King of Prussia
   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

ENGINEERING DISTRICTS                                                                   Coordinate with the National Geodetic Survey (NGS)
GPS at PennDOT




                 3
                       GPS at PennDOT
                         Field Equipment


• Pre 1996 = Conventional Survey Techniques




  Wild T2 Theodolite              Zeiss Ni2 Automatic Level
                                                              4
                    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     Trimble 4700
       1996               Base                            5
                          1999
               GPS at PennDOT
                  Field Equipment


• 2006 = PennDOT started purchase of GPS+GLONASS


                     Trimble R8 (GPS only) = 2003+


                     Trimble R8 GNSS (GPS+GLONASS) = 2006+




                                                       6
                  GPS at PennDOT
CORS = National Coverage thru the National Geodetic Survey




                                                        7
                    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!)
                                                                       8
 Soon to be upgraded to Trimble NetR9 w/ Zephyr Antenna (GNSS)
              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)             9
            GPS at PennDOT
CORS = 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   10
           GPS at PennDOT
CORS = Examples – District 2-6 - Potter County




                 GPS Antenna




          GPS Receiver with Computer




                                                 11
            GPS at PennDOT
CORS = Examples – District 10-0 HQ - Indiana Co


                  GPS Antenna




           GPS Receiver with Computer




                                                  12
    GPS at PennDOT
VRS = Virtual Reference System




                                 13
                                     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
                                                                                                        14
     GPS at PennDOT
VRS = PennDOT Coverage – SW PA
  http://www.dotvrs.state.pa.us/




                                   15
       GPS at PennDOT
VRS = Vendor (KeyNetGPS) PA Coverage
       http://vrs.keynetgps.com/




                                       16
          GPS at PennDOT
VRS = Possible State-wide PennDOT Coverage
       http://www.dotvrs.state.pa.us/




                                             17
                        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
                                                                      18
                                 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)                                                           19
   •   http://www.dot.state.pa.us/Internet/Bureaus/pdBOS.nsf/FormsAndPubsHomePage?OpenFrameSet

								
To top