I've a list of coordinates which were recorded in a last years aerial survey. Besides this I've the flightlog. The list of coordinates was created "manually" by writing down the position into a spreadsheet.

The projection of the flightlog data is: WGS84, EPSG4326

This files works fine and the locations seem to be correct.

Now I'd like to create a point-shapefile from my excel-spreadsheet. The problem right now, is that I don't have any information of the used projection. When I try to use EPSG4326 I get a gap (see screenshot).

enter image description here

The coordinates are as follows:

S074233 E0341051

S074109 E0340115

S073729 E0340115

S071631 E0342037

S071628 E0342837

S071409 E0343446

S071525 E0343546

I'm a bit perplex. Maybe important to know that they maybe used Skydemon or Garmin as GPS recorder. The area of interest is in Tanzania. I've access to ArcGIS and QGIS.

1 Answer 1


These coordinates are just WGS84 degrees, but written as degree-minutes-seconds without any delimiter.

With an excel sheet, it should be easy to separate them and put them into a decimal degrees format, with a trailing minus for the southern hemisphere.

As an example, S074233 E0341051 should be converted to

 - (´07`+`42`/60+`33`/3600) = -7.70916667
    `034`+`10`/60+`51`/3600 = 34.18083333
  • Okay, I've tried it but failed, maybe I miss something. Could you give an example for the first pair of coordinates? How it should look like...
    – dan_ke
    Aug 15, 2015 at 17:40
  • 1
    See my extended answer.
    – AndreJ
    Aug 15, 2015 at 18:12
  • I've tried this and the point appears closer to my flightlog/track but is still ~1,8km off the line. I can image that there is some uncertainty when they recorded the points with the handheld GPS because the plane is moving, but is such an enormous inaccuracy possible?
    – dan_ke
    Aug 15, 2015 at 19:13
  • one question about that, are the points in good relation to each other, (i.e. they make a good line) but all uniformly off? It could be a different geographic coordinate system (don't know what it would be though) if that's the case.
    – mr.adam
    Aug 15, 2015 at 19:42
  • I forgot to put brackets around my first formula. Can you try again? I doubt that GPS track something else than WGS84, not sure about the flight log.
    – AndreJ
    Aug 16, 2015 at 5:58

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