I attended a lecture by him around 1990. Maybe I was not the Turing Award class of computer scientist, was not sooo impressed what he spoke about. Remember Parnas [1] approx. the same year much better.
Around 1998 Gray had built something called TerraServer, must have been years before Google Maps or OSM. It was a real eye opener at the time to see my little house in the middle of nowhere in Northern Europe on the internet published for free by an American company. At the time PC disk sizes where still measured in Megabytes, so you weren't even able to store that many aerial pictures. At least not pictures of current size. Probably they were smaller then, don't have any data.
I was surprised by the date of the article at first!