The declassified aerial images are from 1920', shot by various sensors and archival files which belong to various groups, such as NASA, U.S.Air force, U.S.Navy, Ordance Survey, AHAP and so on.
        The aerial images, covered all over the world, can be very intuitive to learn about the natural conditions and development in the different period. Shooting area covers nearly all the country's major cities. aerial images are divided into two kinds approximately: One is uesd to produce  topographic maps and images. All of these images are shot from high-altitude with ortho-mode, are large scale, and covered towns and urban; the other is required by military, aerial images are used for military operations, are small scale, and covered nature feature.
        The scale of the declassified aerial image is between 1:5000 and 1:100000.Most of images are well structured and clear. In images, landmark buildings can be easily identified, houses and streets and other details are almost as well as today's high resolution images.
        Need more details, please contact with Beijing Top View Technology Co., Ltd.