Post on 05-Jan-2016
2013 Kentucky GIS Pre-Conference Workshop
GPS Technology: Survey vs. Mapping
Mr. Jeff Clark, PLS -- Precision Products Geospatial Division
Mr. Eric Muncy – Precision Products Geospatial Division
Sputnik
Launched in 1957
First man made satellite
Transmitted radio signals
Lived for about 3 months
US Military
First used in the 1960s
To track nuclear power vehicles - ships
Korean Flight 007
Shot down September 1983
Accidently was in Russian Air Space
Presidential Order was signed to make GPS available for civilian use
Selective Availability (SA)
1989 – Intentional dithering of the satellite clocks by the DOD called SA was instituted in 1989.
2000 – President Clinton ordered SA to switched off on May 2, 2000.
Had little to no effect on surveying applications of GPS
Greatly improved consumer grade GPS
BASE STATION
Different Grades of GPS?
Consumer or Recreational grade…
Consumer Grade Inexpensive
15 to 30 feet accuracy
Good for general locations Navigation Street Signs Trees Buildings (911)
Mapping Grade…Mapping/GIS Grade
1 inch to 10 feet accuracy
Digital Clipboard
Good for more accurate locations Hydrants Manholes Roads
Survey Grade Centimeters accurate
Most robust
Good for the accurate locations related to: Control networks Land boundaries Topographic & Engineering
Surveys
What is the freaking difference??
Survey vs. Mapping
Collection of Attributes/Photos Taking GIS data out with you
Mapping - Software
Stakeout operations Volumetric calculations Coordinate Geometry Metadata - Datums, NAD 83, Geoids
Survey - Software
• VRS – Virtual Reference Station
• Free Service (Anyone to use)
• Can be used in real time (Cell phone / Cell modem) or back in the office to process GPS data
• Continuing to be improved (location and accuracy)
• http://kycors.ky.gov/
KYTC VRS - Basics
KYTC VRS – Basics
THEN
KYTC VRS – Basics
NOW
Questions?
Contact Info:
Mr. Jeff Clark, PLS Cell: 270-559-9097 Email: jeff_clark@yourprecision.com
Mr. Eric Muncy Cell: 859-321-3675 Email: eric_muncy@yourprecision.com