(03-21-2018, 04:07 PM)KevinL Wrote: I'm actually studying remote sensing this term so I should be able to answer some of that (though chutten did a fine job).
Google's an interesting beast because their city imagery these days goes way beyond the typical - as you easily find in their 3D view. This requires multiple passes in differing directions by planes equipped to both take pictures and do Lidar scans; once all that is taken it then would go through a ream of back-end processing to build the 3D environment that can be viewed from multiple angles in their web app.
This ESRI imagery, by contrast, is a simple aerial camera pass which can be done more often, hence it being more up to date.
A few years back I had the opportunity to check out one of the aircraft that does photography for Google Maps when it was here at YKF. Its a small plane, but the amount of electronic equipment crammed into the back was unbelievable. I'm still surprised its able to take off with the amount of equipment they had back there....
Coke