When I started IM I have created a filter at Filter-Panel which shows all files containg GPS data. By accident I have deleted this filter and I wanted to re-create it.
Believe if or not, I do not find a setting which filters by files which contain GPS data. Unfortunatelly, [1] refers only to filter by a specific location but not generally to GPS.
[1] https://www.photools.com/help/imatch/panel_filter.htm#a_gps
1. A simple metadata Value filter for Latitude does this.
2. Or, the IMatch Workflow Categories|No GPS Data category contains all files without GPS data.
It uses the formula "@MetadataTag[gpslatitude,novalue,rawvalue]" for that purpose. Use hasvalue instead of novalue to create a category that contains all files with GPS data.
See hasvalue and novalue (https://www.photools.com/help/imatch/cat_formulas.htm?dl=tag-operators) for more info.