338 
multiply and become more and more difficult to discover. The demand for 
specialists on certain types of interpretation targets will probably increase. 
Without a doubt the future will hold a number of tasks of the traditional kind, 
where the demand for speed of interpretation and number of photographs will 
not be as overwhelming as has been outlined here. 
Bilderklärung im Atomalter 
Es ist in einem Atomkrieg noch wichtiger als in einem »konventionellen» Krieg, sich fortlaufend 
von der Gruppierung und dem Vorhaben des Gegners unterrichtet zu halten. Auf dem Kampffelde 
kommen Ziele wie Flug- und Marinehäfen, Atomkanonen, Batterien für Roboterwaffen u. s. w. vor, 
deren Lagen es besonders wichtig ist, feststellen zu können. Eventuelle Truppenansammlungen 
oder andere, für eigene Atomwaffen geeignete Ziele, müssen schnell genug lokalisiert werden können, 
damit eine Bekämpfung eingesetzt werden kann, bevor sich die Lage geändert hat. 
Eine der wesentlichsten Neuheiten in einem Krieg, wo Atomwaffen verwendet werden, oder wo 
es zu befürchten ist, dass solche benutzt werden, ist die grössere Verbreitung der Verbände. Dies 
gilt besonders angreifende Streitkräfte. Das grössere Aufklärungsgebeit bewirkt eine grössere Anzahl 
Bilder. 
Der Anspruch auf schnelle Ergebnisse wird in einem Atomkrieg betont, in dem es gelten kann, 
eine günstige Gelegenheit zwecks Einsatz eigener Atomwaffen auszunützen oder den Gegner zu 
hindern, von den seinigen Gebrauch zu machen. 
Die Ausnützung der Erklärungsresultate, um die vom Gegner angewendete Taktik festzustellen, 
wird von grösster Bedeutung, da es von vitalem Interesse ist, darin schnellstens einen Einblick zu 
bekommen. 
Diese Verhältnisse werden wahrscheinlich beträchtlich erhöhte Forderungen auf den Beobach- 
tungs- und Erklärungsumfang zur Folge haben. 
R. Thorén: Naval 
Photo Interpretation. 
(Pubi. VII T 2) 
Capt. R. Thoren of Sweden, read his paper, on Naval Photo Interpretation: 
In my report to the Seventh Congress of Photogrammetry, Commission VII, 
in Washington, in September 1952, entitled »Photo Interpretation in Military 
Intelligence» I also presented some examples of Naval Photo Interpretation, 
illustrating its strategical and tactical application. There I mentioned, that the 
most important and sometimes the most arduous task, when interpreting re 
connaissance photographs of naval targets, is identifying the different types of 
vessels, their classes and units. The difficulty is that the scale of the photo 
graphs is often considerably smaller than that normally necessary in order to 
be able to analyze the details of the various craft. 
Many times, however, a close study of wave systems and wake patterns of the 
ships will give the interpreter all information needed for ascertaining type as 
well as class. This subject, therefore, seems to be of special interest and worth 
closer examination. 
The disturbed body of water behind a moving ship, which is set into motion 
by the passage of the vessel, is called wake, wake current or stern wake. This 
forward-moving water has a certain influence on the effect of the propeller. Its 
characteristic pattern, however, is not caused by the propellers, as is often 
believed, but depends on the design of the hull of the ships, especially the stern. 
The wake varies with the speed, every different hull design and stern shape, 
however, will present its own characteristic wake pattern. This fact is of great 
importance when analyzing aerial photos. By an intimate knowledge of such 
characteristics it is possible to state what ship it is, even if the hull perhaps 
does not appear in the picture, only her wake. 
The photo interpreter in World War II seems not to have practised such a 
thorough-going fashion when analyzing reconnaissance pictures. Mostly, distinc 
tive wakes were studied for estimating speed by visual reconnaissance only. 
Through series of experimental tests with vessels of different types and classes 
as »targets» it has been possible to state the usefulness of wave and wake patterns 
as decisive factors when analyzing verticals, even as regards relatively small 
scale ones. Low obliques may offer good possibilities as well. High obliques, on 
the other hand, are as a rule more or less unsuitable for the purpose.