I have debunked an UFO sighting one night over Vacaville, CA several years ago because I knew that it was a blimp and also knew the schedule that it would pass near our area. Another was a crop circle near Solano College in Suisun Valley. Upon entering the huge circle, I went toward the center and found what I was looking for; a 1" hole that was used to create the circle. I've also debunked another UFO sighting near Redding, CA where two witnesses misidentified one of our KC-10 tankers that was training over the area. The aircraft is based at Travis AFB, CA.
I am on the record for stating that the majority of UFO sightings can be explained with down-to-earth explanations, but the reports that I am interested in are the radar/visual reports such as the Bariloch UFO encounter where the UFO flew along side the airliner as passengers in the plane and observers on the ground watched. The UFO forced the pilot to conduct a missed approach on final to the airport. the city was also blacked out as the UFO passed overhead.