About GPS coordinates - neayi/soil_and_culture_gps GitHub Wiki

In the files we downloaded from the Internet about soils and possible cultures in regions of France, we are working with geometric data types. Those geometries are given in a specific frame reference: the Lambert 93 projection.

Each time we use GPS coordinates (directly in the parameters of the query.php script or through web services returning GPS coordinates from an IP address or a postal code), we create geometric points in the WGS84 projection.

For the queries detecting the soils and possible cultures nearby a specific location, we need to compute the distance between those two geometries... but for that to work, they need to be in the same projection. Therefore, in the query.php script, each time GPS coordinates (in WGS84) are used, they are converted to Lambert93.

Click here https://georezo.net/forum/viewtopic.php?id=94465 to see how this is calculated.

Use this online converter: https://tool-online.com/en/coordinate-converter.php to check the results.