Types of Aerial Photographs

8/10/2019 Types of Aerial Photographs

1/7

TYPES OF AERIAL PHOTOGRAPHS

Aerial photography most commonly used by military personnel may be divided into two majortypes, the vertical and the oblique. Each type depends upon the attitude of the camera with

respect to the earth's surface when the photograph is taken.

a. Vertical.A vertical photograph is taken with the camera pointed as straight down as

possible (igures !"#and !"$%. Allowable tolerance is usually & from theperpendicular (plumb% line to the camera a)is. *he result is coincident with the camera

a)is. A vertical photograph has the following characteristics+

(#% *he lens a)is is perpendicular to the surface of the earth.

($% t covers a relatively small area.

(% *he shape of the ground area covered on a single vertical photo closely

appro)imates a square or rectangle.

(-% eing a view from above, it gives an unfamiliar view of the ground.

(/% 0istance and directions may approach the accuracy of maps if taken over flat

terrain.

(1% 2elief is not readily apparent.

Figure 8-1. Relationsi! o" te #ertical aerial !otogra! $it te groun%.
http://www.map-reading.com/aptypes.php#fig8-1http://www.map-reading.com/aptypes.php#fig8-2http://www.map-reading.com/aptypes.php#fig8-2http://www.map-reading.com/aptypes.php#fig8-1


2/7

Figure 8-&. Vertical !otogra!.

a. Lo$ O'li(ue.*his is a photograph taken with the camera inclined about 3 from

the vertical (igure !", and igure !"-%. t is used to study an area before an attack, to

substitute for a reconnaissance, to substitute for a map, or to supplement a map. A lowoblique has the following characteristics+

(#% t covers a relatively small area.

($% *he ground area covered is a trape4oid, although the photo is square or

rectangular.

(% *he objects have a more familiar view, comparable to viewing from the topof a high hill or tall building.

(-% 5o scale is applicable to the entire photograph, and distance cannot be

measured. 6arallel lines on the ground are not parallel on this photograph7

therefore, direction (a4imuth% cannot be measured.


3/7

(/% 2elief is discernible but distorted.

(1% t does not show the hori4on.

Figure 8-). Relationsi! o" lo$ o'li(ue !otogra! to te groun%.


4/7

Figure 8-*. Lo$ o'li(ue !otogra!.

c. Hig O'li(ue.*he high oblique is a photograph taken with the camera inclined about

13 from the vertical (igures !"/and !"1%. t has a limited military application7 it is usedprimarily in the making of aeronautical charts. 8owever, it may be the only photography

available. A high oblique has the following characteristics+

(#% t covers a very large area (not all usable%.

($% *he ground area covered is a trape4oid, but the photograph is square orrectangular.

(% *he view varies from the very familiar to unfamiliar, depending on the height

at which the photograph is taken.

(-% 0istances and directions are not measured on this photograph for the same

reasons that they are not measured on the low oblique.

(/% 2elief may be quite discernible but distorted as in any oblique view. *he

relief is not apparent in a high altitude, high oblique.

(1% *he hori4on is always visible.


5/7

Figure 8-+. Relationsi! o" ig o'li(ue !otogra! to te groun%.

Figure 8-,. Hig o'li(ue !otogra!.

d. Trietrogon.*his is an assemblage of three photographs taken at the same time, one

vertical and two high obliques, in a direction at right angle to the line of flight. *he

obliques, taken at an angle of 13 from the vertical, sidelap the vertical photography,producing composites from hori4on to hori4on (igure !"9%.
http://www.map-reading.com/aptypes.php#fig8-7http://www.map-reading.com/aptypes.php#fig8-7


6/7

Figure 8-. Relationsi! o" caeras to groun% "or trietrogon !otogra!/ 0tree

caeras.

e. 2ulti!le Lens Potogra!/.*hese are composite photographs taken with onecamera having two or more lenses, or by two or more cameras. *he photographs are

combinations of two, four, or eight obliques around a vertical. *he obliques are rectified

to permit assembly as verticals on a common plane.

f. 3on#ergent Potogra!/.*hese are done with a single twin"lens, wide"anglecamera, or with two single"lens, wide"angle cameras coupled rigidly in the same mount

so that each camera a)is converges when intentionally tilted a prescribed amount (usually

#/ or $3% from the vertical. Again, the cameras are e)posed at the same time. orprecision mapping, the optical a)es of the cameras are parallel to the line of flight, and

for reconnaissance photography, the camera a)es are at high angles to the line of flight.

g. Panoraic.*he development and increasing use of panoramic photography in aerial

reconnaissance has resulted from the need to cover in greater detail more and more areasof the world.

(#% *o cover the large areas involved, and to resolve the desired ground detail,

present"day reconnaissance systems must operate at e)tremely high"resolutionlevels. :nfortunately, high"resolution levels and wide"angular coverage are

basically contradicting requirements.

($% A panoramic camera is a scanning type of camera that sweeps the terrain ofinterest from side to side across the direction of flight. *his permits the panoramiccamera to record a much wider area of ground than either frame or strip cameras.

As in the case of the frame cameras, continuous cover is obtained by properly

spaced e)posures timed to give sufficient overlap between frames. 6anoramic

cameras are most advantageous for applications requiring the resolution of smallground detail from high altitudes.


7/7

8-). TYPES OF FIL2

*ypes of film generally used in aerial photography include panchromatic, infrared, and color.;amouflage detection film is also available.

a. Pancroatic.*his is the same type of film that is used in the average hand"heldsmall camera. t records the amount of light reflected from objects in tones of gray

running from white to black.

Documents

Types of Aerial Photographs