I don’t know anything about Jacques Vallee.
Jacques Vallee is a no-nonsense investigator/scientist. His background is information systems and networking. He developed data bases of UFO sightings and saw strange correlations between certain elements in all sightings.
Like John Keel, he is not well liked in the UFO-nut community, because, although he believes that UFO’s are real, he does not support the extraterrestrial hypothesis.
His book “Dimensions” is riveting. He goes back through history and shows that UFO’s have been with us a long time, and that the idea that they are “aliens” visiting Earth makes no sense when you look at the nature of actual sightings.
http://www.bibliotecapleyades.net/ciencia/ciencia_vallee_a.htm
A very good synopsis: Heretic among heretics: http://www.bibliotecapleyades.net/ciencia/ciencia_vallee08.htm
Physicist, computer scientist, author, he has been involved in the UFO subject for probably 50+ years. In an academic environment and also as a defense consultant.
Ever see “Close Encounters of the Third Kind”? Remember there was a French fellow (scientist)who was involved with the interpretation and eventual planning of meeting the extra-terrestrials?
The part in that movie was strongly based on a real person. Jacques Valle.
He wrote a couple of books about UFOs in the late 60s early 70s