The National Geo-spatial Information is the government agency responsible for aerial photography and has an archive of aerial photography dating back to the 1930's. The photography is at a variety of scales and has provided a complete coverage of the country since the 1950's. These are all vertical photographs taken from aircraft. Photography is continuously re-flown to provide new photography for ongoing map revision and for scale to users.
Unlike a generalised line map almost all detail is visible on aerial photography. The user, although unable to make accurate measurements on the photograph, is able to perform his or her own interpretation of what exists on the ground. Aerial photographs are also an historic record of what existed at the time the photograph was taken.
Modern aerial photographs are a standard contact size of 23 x 23cm. Enlargements of up to three times of a photograph area are available. Enlargements greater than three times are only possible of portions of the original photograph. Overlapping stereo pairs may be purchased for stereo viewing, providing the user with a 3-dimensional image. Colour photography is also available in selected areas.