Yet another option is the off-the-shelf goTenna Mesh devices, coupled with the GliderLink app on a smartphone. This is designed so gliders in the air can "see" each other, but ground stations (same type of devices) can listen in. Cell service NOT required. Such ground stations could in principle send the data to OGN and/or glideport.aero.

There is no lack of options, the real problem is too many options, i.e., no standardization. The FlightAware devices may be the best thing *if* the gliders are equipped with ADS-B anyway. The OGN-trackers are good *if* the gliders are equipped with FLARM. Around here both are rare.