Skip to content

OSGeo/PROJ-CRS-Explorer

Repository files navigation

CRS Explorer

Browse on PROJ coordinate reference systems, fast and easy.

Visit

https://jjimenezshaw.github.io/crs-explorer/

Click on the map if you want to select only the systems that include that location. Select as well the type of CRS, and the authority of your interest. For EPSG systems you can click the code-link to visit their specs.

Selecting the checkboxes next to the "areas of use" will display a rectangle in the map.

Use the Filter by name form to search on the Name column (click the info <i> to understand the syntax).

There are available the WKT 1 and 2 (generated by PROJ as WKT1_GDAL and WKT2_2019) as links to static files. If your browser is helpful, you can see them also as a tooltip.

It looks something like this:

alt text

You can directly show all available reference systems in this link, more than 12500 so far.

Why

Many people asked "Which coordinate (reference) system should I use in my project/country/state/location?", "Really, is there a vertical one in my country?" or "What is the right WKT for this CRS?".

Well, instead of doing a research every time, just look what is available in PROJ. The command line application projinfo can be tedious, and not easy for many people. For some use cases, this is an "easy to use" version available on the browser.

PROJ includes an updated version of EPSG database, ESRI and some other authorities (looking for a deprecated ESRI CRS? visit ESRI codes analyzer).

The behavior was inspired in https://cdn.proj.org (that shows the grid files from PROJ-data in a map) in combination with the option --list-crs of the program projinfo

Data generation

The static html page loads a json file generated from PROJ with pyproj. To produce the crslist.json file you have to build pyproj with the desired version of PROJ. In my case, I did this:

  • export PROJ_DIR=~/proj_install_folder/
  • export PROJ_DATA=~/proj_install_folder/share/proj/
  • pip uninstall pyproj
  • pip install git+https://github.com/pyproj4/pyproj.git
  • python3 ./scripts/proj2json.py

Or have a look at the folder scripts. You can run easily in a docker image.

Thanks