That’s my Dad. I think that’s the picture which appeared in the December, 1957 National Geographic.
I was going to ask... Cool dad!
My first GPS was a $1000 Magellan that gave lat-long coordinates. It was degraded for military reasons and loran was still considered superior for coastal navigation. I learned ded-reckoning on paper charts and would cheat by, “aiming” an AM radio at land stations to triangulate.
It’s amazing that they are giving away GPS sets in cracker jack boxes. Well, almost!)
I’ll look for your book.