When I worked with ArcMap, I had no problem with choosing projection

ArcMap has a large number of predefined projections organized by world, continent, and country. You can navigate quickly to appropriate projections for any part of the world.

My current employer did not buy ArcMap, but I still need to choose an appropriate projection for my tasks. For example, I have got a list of coordinates in degrees (WGS84). I need to define (for example)

  • some distances in meters
  • areas in square meters
  • midpoints
  • centroids

So, I need to select appropriate projection, transform original coordinated to this projection, make calculation, and sometimes transform result back to WGS84.

For this purposes I need mechanism to select the appropriate projection. What is it?

  • 1
    What software are you using?
    – reevesii
    Sep 5, 2018 at 10:10
  • @reevesii - I would prefer to use ogr/gdal with python for projecting coordinates
    – Loom
    Sep 5, 2018 at 11:34
  • How did you determine what CRS to use while using ArcMap?
    – reevesii
    Sep 5, 2018 at 12:11
  • What software are you using for your tasks (area, centroid etc)? Some products can calculate directly from lat/long without needing to project.
    – Don
    Sep 5, 2018 at 13:54
  • @Don - My data is stored in Hive. So I can use Spark libraries, or some other libraries for python, scala, java, R
    – Loom
    Sep 5, 2018 at 14:01

1 Answer 1


I often determine which projection to use with a UTM Zone map such as that shown below.

enter image description here

So if one was representing an area in western Madagascar (large island southeast of African continent) in their GIS, for example, they would likely choose WGS 84 / UTM zone 38S as their coordinate reference system. This is the column number this area is in within this UTM map. The S in 38S indicates that this area is south of the equator.

To project a coordinate list of points, you can use the project function of your GIS to project your points to the appropriate coordinate reference system. Then perform your various analyses and reproject back to the geographic coordinate system using the same project function if need be.

  • Thank you (+1). Maybe it's the answer to my question. I guess my next question will how to project map to specific UTM CRS with python/ogr
    – Loom
    Sep 5, 2018 at 11:36
  • I believe gdalwarp can be used to project. But, yes if you are unable to succeed with this projection process, a new question identifying where you are stuck would be appropriate.
    – reevesii
    Sep 5, 2018 at 11:58

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