From: Carlos Aiken [aiken@utdallas.edu]
Sent: Thursday, February 06, 2003 2:00 AM
To: 'Carlos Aiken'

These are the steps for differential correction in Pathfinder:
 
Data: for example, there are r090718a.ssf (raw data file) and Waypoint.wpt 
(waypoint file).
 
1. Open data file
    On menu bar: File---Open
 
2. Display the map
    On menu bar: View---Map
    
3. Differential Correction
   On menu bar: Utilities---Differential Correction...
 
   1) Select rover files
       we've already opened the only file r090718a.ssf. If you want to 
postprocess some files at one time, click Browse.... And select all files you 
want to postprocess in "Select Rover Files" window and Open them.
    
   2)  Select Base files
       Click on Browse... And in "Select Base Files" window, select base file:
        ARL2001090707.dat
        ARL2001090713.dat (Base file with the same date)
     And open them.


All base files must be in the same format. The Trimble SSF and DAT formats
and the RINEX format are supported. Compressed SSF, DAT or RINEX base files, with a .ZIP, .EXE, or .GZ extension are also supported


 
   3) Confirm Selected Base Files
        In this window, we can see the Rover names, base names, Coverage, Start 
Time, End Time...
        It is important that the Coverage should be 100%. if not, that means, 
the base file is not the one you need or you need more base files to cover all 
time span in your rover files.
 
        The next window is " Reference Position". It displays information of 
base station-- Arlington. Just click OK.
 
   4) Choose the fold to put your corrected files
      And the corrected file extension should be .cor.
 
 
    5) Choose Processing Type
      At the bottom of the Differential Correction window, choose "Code 
Processing Only"
 
Now, "OK"
 
     Close the "Differential Correction Completed" window( if nothing is wrong).
 
4. Grouping
   On menu bar: Utilities---Grouping
   Because there are probably hundreds of readings for one point in your rover 
file, you need average them and get one point feature for each point you 
occupied. 
 
   1) Select Files: Select all your corrected files to group them at one time.
                          The file extension should be .cor
 
   2) Create a output file name
      Click on Output File... 
      Then choose the fold and give the grouped file a name.
 
   3) Grouping Method
      Choose "One group per input file"
   
   4) Create Feature Type
       Choose "Point"
 
Now, "OK".
     
5. Export files
    On menu bar: Utilities---Export...
    
    1) Select grouped file
    2) Select output folder
    
    3) Choose an Export Setup
       Click the arrow to right of the Choose an Export Setup box and choose 
"Sample ArcView Shapefile Setup".
 
Now, "OK"
 
     You don't need to postprocess waypoint file. Just export it into shapefile 
format.