PennDOT Photogrammetry

1
Overview of PennDOT CORS VRS / RTN for Great
Lakes Region Height Modernization
Consortium Charles I. Harpster, Jr., CP,
LSIT (charpster_at_state.pa.us) Geodetic Surveys
Manager
April 13, 2011
2

ERIE
WARREN
SUSQUEHANNA
McKEAN
BRADFORD
1
TIOGA
POTTER
CRAWFORD
WAYNE
4
Oil City
FOREST
WYOMING
ELK
SULLIVAN
LACKAWANNA
CAMERON
LYCOMING
2
VENANGO
PIKE
Dunmore
Dunmore
3
Montoursville
MERCER
CLINTON
JEFFERSON
CLARION
LUZERNE
Clearfield
MONROE
COLUMBIA
LAWRENCE
MONTOUR
10
UNION
CLEARFIELD
BUTLER
CENTRE
CARBON
5
ARMSTRONG
NORTHUMBER- LAND
SNYDER
NORTHAMPTON
BEAVER
INDIANA
LEHIGH
11
SCHUYLKILL
MIFFLIN
Allentown
BLAIR
JUNIATA
Indiana
ALLEGHENY
CAMBRIA
Hollidaysburg
BERKS
DAUPHIN
LEBANON
PERRY
Bridgeville
Bridgeville
BUCKS
Harrisburg
WESTMORELAND
HUNTINGDON
MONTGOMERY
9
WASHINGTON
6
CUMBERLAND
12
8
Uniontown
LANCASTER
PHILADELPHIA
SOMERSET
King of Prussia
BEDFORD
FULTON
FRANKLIN
CHESTER
DELAWARE
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

Zeiss Ni2 Automatic Level
Wild T2 Theodolite
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 GPSGLONASS

Trimble R8 (GPS only) 2003 Trimble R8 GNSS
(GPSGLONASS) 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 RTNs
• 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 NGSs
  database
• NGS Federal Geospatial Summit 2010
  http//www.ngs.noaa.gov/2010Summit/2010FederalGeos
  patialSummitProceedings.pdf
• NGS Survey Control Database
• http//www.ngs.noaa.gov/cgi-bin/datasheet.prl
• PennDOTs Photogrammetry Asset Management System
  (PAMS)
• http//www.penndotpams.org
• PennDOTs Surveying Mapping Manual (Pub. 122M)