Height object reckoning. 
h = height of ground object. 
M == measure of the object picture. 
fj = obliqueness angle of the optical ray which pass by the top of the object. 
a =90° — Q. 
7 =180 ° —(/? + «). 
, , , M sin y M H sin y 
h value will be: 
E sin 
Other method of reckoning. 
Put down: £ = pOb 
A — p O s 
X sill 0 sin ß 
. P b 
tg. e — p 
tg. A = 
ps 
h = BS = BC — SC or B C = H 
SC = 
oc 
tg. (0 + A) 
Where from li = H i 
= H 
tg. (0 + £) 
tg. (0 + A) 
tg. «-) + £) 
tg. (0 + A). 
Lt. Col. B. von Vegesack of Sweden, presented his paper, on Photo Inter 
pretation on the Eve of the Atomic Age: 
Military photo interpretation found its form during the second World War, 
which it has maintained since then. Changes have occurred mainly in the form 
of improved equipment (optics, cameras, film, stereoscopes et ah). 
It would seem, however, that photo intelligence already — or soon — will be 
accorded a still greater importance since warfare, threatened with atomic 
weapons, is on the eve of great changes. The most decisive factors can be sum 
marized as follows. 
One of the most basic innovations in a war, where atomic weapons are used or 
may be expected, is the increased spreading out of the units. This is especially 
true of an attacking force. 
In an atomic war it is of greater importance than in a conventional one to 
keep continual track of the grouping and activities of the enemy. In the war 
area there are such weapons as airfields, navy bases, atomic artillery, guided 
missile batteries etc. whose positions it is of vital importance to locate. Any 
concentration of troops or any other target, suitable for one’s own atomic weap 
ons, must be localized without delay so that an attack may be made before 
the situation has changed. Photo reconnaissance is doubtless the most effective 
means of acquiring such information. 
The number of intelligence photos will be far greater, making a correspondingly 
greater demand on the photo interpretation capacity. 
The enemy camouflage technique, developed to counteract photo reconnais 
sance, makes the discovery of targets slower and more difficult — although field 
fortifications, erected against the risk of atomic attack, may not be as well 
camouflaged as others, owing to insufficiency of time. 
The demand for speedy results is accentuated in atomic warfare, where it 
can be a question of utilizing a favorable occasion for one’s own atomic weapons 
or to hinder the enemy from using his. 
It is of supreme importance to exploit thoroughly the results of the inter 
pretation in order to ascertain enemy tactics without delay, since they are of 
vital interest. 
A great amount of interpretation material will cause difficulties with regard 
to procuring a sufficient number of qualified interpreters. The military objectives 
337 
22 
B. v. Vegesack: Photo 
Interpretation on the Eve 
of the Atomic Age. 
(Publ. see General 
Report VII) 
mm