Page:Ruppelt - The Report on Unidentified Flying Objects.djvu/261

 sighting at Brookley. First of all, radar-visual sightings were the best type of UFO sightings we received. There are no explanations for how radar can pick up a UFO target that is being watched visually at the same time. Maybe I should have said there are no proven explanations on how this can happen, because, like everything else associated with the UFO, there was a theory. During the Washington National Sightings several people proposed the idea that the same temperature-inversion layer that was causing the radar beam to bend down and pick up a ground target was causing the target to appear to be in the air. They went on to say that we couldn’t get a radar-visual sighting unless the ground target was a truck, car, house, or something else that was lighted and could be seen at a great distance. The second reason the Brookley AFB sighting was so interesting was that it knocked this theory cold.

The radar at Brookley AFB was so located that part of the area that it scanned was over Mobile Bay. It was in this area that the UFO was detected. We thought of the theory that the same inversion layer that bent the radar beam also caused the target to appear to be in the air, and we began to do a little checking. There was a slight inversion but, according to our calculations, it wasn’t enough to affect the radar. More important was the fact that in the area where the target appeared there were no targets to pick up—let alone lighted targets. We checked and rechecked and found that at the time of the sighting there were no ships, buoys, or anything else that would give a radar return in the area of Mobile Bay in which we were interested.

Although this sighting wasn’t as glamorous as some we had, it was highly significant because it was possible to show that the UFO couldn’t have been a lighted surface target.

While we were investigating the sighting we talked to several electronics specialists about our radar-visual sightings. One of the most frequent comments we heard was, “Why do all of these radar-visual sightings occur at night?”

The answer was simple: they don’t. On August 1, just before dawn, an ADC radar station outside of Yaak, Montana, on the extreme northern border of the United States, picked up a UFO. The report was very similar to the sighting at Brookley except it happened in the daylight and, instead of seeing a light, die crew