[photo-3d] Re: aerial stereos

[JNorman805@xxxxxxx]

More on Ray Hannison's request for aerial stereos:

One of the big services that provides these aerial pairs is Keystone Aerial Surveys in Philadelphia.

A web search using the word "photogrammetry" reveals many more.

Supposedly, the government's Aerial Photo Summary Record System ("APSRS") is a good source, but their emphasis is said to be high altitude photography that's best suited for picking military targets, and needing extremely skilled analysis to overcome the lack of detail (maybe that's why we blasted the Chinese embassy in Yugoslavia...)

An organization called the American Society for Photogrammetry is said to have a good index of what's available.

I'm told the commercial archives concentrate on low-level, high detail shots of smaller areas.  

I'm also told that prices can vary wildly, from $15 a pair to sky's-the-limit, so it may pay to check multiple sources.

Jim Norman