One of my field guys collected positions (updated features in an .imp file that I generated from our billing system) in the same file over multiple days. Usually I "split" the file at the end of each day for him (extract features from the file including updated positions), but I got really busy on another project and forgot this past time. Of course, this would happen over the weekend of the time change.

Now I have an SSF I cannot differential correct because it spans 2 time zones. I need to split this file into the 2 days it was collected, AND I assume change the date/timezone in the header in order to correct each day separately. How can I achieve this?

If I use SSF Record editor, delete (strike through) the positions from one day and save-as, I assume the post processing will still fail since the collection range in the header is across multiple days including a time change.

1 Answer 1


Aha; I assumed incorrectly! PFO's Differential Correction Wizard based the Start Time and End Time of the correction log on the positions in the SSF, not the header you cannot edit in SSF Record Editor.

To summarize - I created 2 "save-as" SSFs from my original SSF, one for each day.

I then opened them in PFO's SSF Record Editor, used "GoToRecord by Time" to find the end of the first day/beginning of the second day.

I then selected all the positions before or after that split point (depending on the day I wanted the SSF isolated to) and used the "Delete Selected Records" function, which actually just strikes through those records (you can always get them back).

Then I used the Trimble Pivot Website to manually download a RINEX log file from the CORS station for each time period.

Then I corrected each edited SSF in the Differential Correction Wizard using the downloaded log file.

  • 1
    I do this sort of split regularly so here are two tips if you ever have to do this again: * First, when you do "Save As", give a new file name and don't save the deleted records. I've found that PFO sometimes screws up because of the records you think you have deleted. * Second, once you have your two separate files, you can open them one at a time in PFO, change something unimportant (for example edit a Comment and save the feature) then save the file. This updates the HDR record according to the actual times in the (cut down) file.
    – Trams
    Commented Feb 7, 2017 at 6:47

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