This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
There are available two validators for your BE form
- tx_geopicker_lat_eval accepts values from -90° to 90°
- tx_geopicker_lon_eval accepts values from -180° to 180°
For elevation field you can use just
int validator of TYPO3, in all cases you can use also
In ViewHelpers section you'll find also VH's to validate coordinates in your view.