ES 771 Lecture
James S. Aber

INTRODUCTION TO AERIAL PHOTOGRAPHY

People have acquired aerial photographs ever since the means have existed to lift cameras above the Earth's surface (see RSE fig. 3-5). The desire to see the Earth "as the birds do" is strong for many practical and aesthetic reasons. Aerial photography, like most other forms of remote sensing, was developed primarily for intelligence gathering and military purposes (see RSE figs. 3-6 & 3-7), which continue to be major applications. Air photos are taken normally from airplanes or helicopters, but many other platforms may be used, including: balloons, tethered blimps, gliders, rockets, model airplanes, kites (see RSE fig. 3-9), and even birds (see RSE fig. 3-11). Recent innovations for cameras, films and platforms have led to new commerical, scientific and artistic possibilities for aerial photography.

Kite aerial photography--KAP.

Hot-air blimp aerial photography.

Balloon aerial photography--BAP.

Manned color-infrared aerial photography.

Air photos may be taken in various orientations--vertical or oblique--to suit the needs of the user (see RSE figs. 4-1 to 4-3). The standard air photo is taken in vertical position. Film format is 9 inches (23 cm) wide, and camera lens has a 6-inch (152 mm) focal length (see RSE figs. 4-7 & 4-8). Photos are taken along predetermined flight lines in overlapping sequence. This allows for complete ground coverage and for stereo (3-D) viewing of overlapping photo pairs.

Examples of airphotos and GIS--AERO-METRIC.

The basis for aerial photography, like all kinds of photography, is light-sensitive chemicals in the film emulsion. These chemicals may react to ultraviolet, visible, and/or short-infrared portions of the spectrum, from 0.3 µm to 0.9 µm wavelength (see RSE fig. 4-20). Many varieties of film and filter combinations have been developed for routine and special purposes in aerial photography.

Film Type Uses of Film
b/w visible panchromatic, normal visible
b/w extended red panchromatic, haze penetration
b/w infrared UV, visible and near-infrared
color visible normal color: blue, green, red
color infrared false color: green, red, near-IR

Color photograph in visible light. Main house at Tallgrass Prairie National Preserve, Chase County, Kansas. Note stone walls, red roof, and surrounding vegetation. Photo date 5/98; © J.S. Aber.
Color-infrared photograph of main house at Tallgrass Prairie National Preserve, Chase County, Kansas. Active vegetation appears in red and pink colors. Photograph taken with a yellow filter to eliminate blue light. Photo date 5/98; © J.S. Aber.

Color-infrared (CIR) photographs are especially useful for camouflage detection, recognition of vegetation and water bodies, and display of special features. Multiband photography is taking simultaneous photos in different portions of the spectrum (see RSE fig. 4-11). For example, four-band photography might include separate b/w photographs in blue, green, red, and near-infrared bands.

U.S. National aerial photography program--NAPP.
U.S. National high altitude photography--NHAP.

Glossary of photographic terms.

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© Notice: ES 771 is presented for the use and benefit of students enrolled at Emporia State University. Any other use of text, imagery or curriculum materials is prohibited without permission of the instructor. Last update 2006.