The data broadcast from ADS-B includes both GPS position (Lat + Lon) and altitude. If you created a bounding box, you could add a height parameter to make it 3D, and get a list of such aircraft and the timestamps of their transmissions while inside that (3D) bounding box.
That wouldn't be too difficult to do with a little bit of filtering of the feed coming out of an ADS-B receiver.
That wouldn't be too difficult to do with a little bit of filtering of the feed coming out of an ADS-B receiver.