{"id":47,"date":"2023-03-08T02:05:05","date_gmt":"2023-03-08T02:05:05","guid":{"rendered":"http:\/\/rarakihydro.com\/?p=47"},"modified":"2025-07-29T23:54:25","modified_gmt":"2025-07-29T23:54:25","slug":"4-ways-to-find-out-coordinate-reference-system-information-crs-and-set-it-in-a-xarray","status":"publish","type":"post","link":"https:\/\/rarakihydro.com\/index.php\/2023\/03\/08\/4-ways-to-find-out-coordinate-reference-system-information-crs-and-set-it-in-a-xarray\/","title":{"rendered":"4 ways to find out Coordinate Reference System information (CRS) and set it in a xarray"},"content":{"rendered":"\n

When you want to process raster data (arrays with geo-coordinates) with Python, there are several options. It was the most straightforward for me to use Python, read all the data in xarray <\/a>and process it with rasterio <\/a>using rioxarray<\/a> (tutorial by University of Colorado Boulder here<\/a>).<\/p>\n\n\n\n

Rioxarray requires data arrays, x-y coordinate array, and coordinate reference system information (CRS) to function. However, it is not always easy to find out and set the CRS, as different files stores CRS in different places (I wish for more advancement of data-standardization!).<\/p>\n\n\n\n

In this article, I summarize 4 ways to find out and set the CRS in a xarray dataset.
Disclaimer<\/em>: I am not the super expert on the projection system, so please use the code at your own risk and let me know when you find any mistakes!<\/p>\n\n\n\n

To start off, I import libraries as follows.<\/p>\n\n\n\n