Tech Notes Tip
Technical Support Document on Adding a New Reference Station for Post-Processing in Pathfinder Office Software (Click here for the pdf)

After opening Pathfinder or GPS Analyst and the project that you wish to post-process off of:

 - Click Utilities / Differential Correction.  Or Start GPS Editing and Differential Correction in ArcGIS

 - Highlight the file you are Differentially Correcting or tap the plus (+) sign to add the file in & click 'Next.'

 - Depending on what receiver collected, the .ssf file you can select Automatic Standard Carrier and Code
   Processing. This is what PFO defaults to if you have a Geo XT / Pro XT. A Pro XH or Geo XH can use the H-Star
   Processing for better accuracy. Then click 'Next.'

 - Click 'Next' through the Setting Screen.

 - Click 'Base Provider Search' and tap 'Select' on the right. Then tap 'New' at the bottom of the screen. Type in the
   name of the new Base Station "MN DOT," for example. Don't worry about the other information (street address
   etc.).

 - Tap the 'Base Station' tab. Skip the receiver info and key in the 'Reference Position' found at the MNCOR
   Website (http://www.olmweb.dot.state.mn.us/CORS.GPS/StationData.pdf)

                Example:
                Saint Cloud, MN
                Lat: 45-33-51.22881 N
                Long: 94-10-48.15944 W
                HAE(m): 296.014

 - Tap the 'Internet Server' tab and enter the 'Base File Address Format.' An example for St. Cloud is below. You
   may need to switch the 30-sec-24hr if the station you wish to use logs at a different rate. You would also want to
   change the RefData.07 to RefData.08. The last thing you need to edit from the below address is the station you
   wish to use. So change the StCl to whatever base you wish to add. Example, StCl to ApVy. Then click 'Apply'
   and 'OK.'

                Example:
                ftp://ftp.olmweb.dot.state.mn.us/CORS.GPS/30-sec-24hr/RefData.07/Month.%Mmm%/Day.%DD%/StCl%DDDDD%0.%yy%o.zip

 - Highlight your new MN DOT Provider on the list and click 'OK.'

 - Click 'Next.'

 - Leave these settings at defaults and click 'Start.'

If you have any questions on this, please contact Kory Thurnau (Technical Support Specialist) at 888.797.4774. Kory did confirm with Dave Zenk the ITRF (International Terrestrial Reference Frame) shift/ adjustment is shifted NW about 3.41 feet.  This was comparing the LeSeur Station.  He emphasized the importance of using the MNCORS, as the new adjustment for HARN is near implementation.  For the most part, the knew adjustment is minor with shifts around 2-3 cm with exception of a few stations on the North Shore of Lake Superior.  In the case of our Dakota friends, they will need to either perform an adjustment/localization, or use their own values for the base station. http://www.ngs.noaa.gov/itrf1fcr.shtml

Welcome to 'Tech Notes' - Frontier Precision's e-newsletter! 'Tech Notes' is designed to keep you informed with tips and information on the latest technology in surveying, construction, and GIS. Our company goal is to help you be more efficient and more profitable with today's technology!

January 11, 2008