60 REPORT OF COMMISSION VII 
While strategic photo reconnaissance is generally carried out as vertical 
photography, both vertical and oblique photography are applied in tactical 
reconnaissance. Obliques have proved themselves popular with ground forces, 
owing to the fact that they give a survey of the terrain even behind protecting 
ridges and heights in a natural way. They are used with preference as annotated 
photos in intelligence, and at the same time successfully complement both topo- 
graphical maps and verticals. 
Through low obliques, one can give landing craft clear, eloquent information 
about the details on the beach which is to be used. Put together to form a 
panorama, such obliques give a surveyable picture of the coastline and the 
defenses which will be met during the advance in the terrain. 
The following section about photo-interpretation gives, through examples, 
some of the tactical intelligence one can get from photo analysis of the very 
detailed reconnaissance photographs of good quality. 
GROUND PHOTO RECONNAISSANCE 
Ground photo reconnaissance is chiefly an aid to the tactical intelligence 
service within the battle area, but, in the broader meaning of the word, can also 
be said to be a strategic intelligence organ with a place to fill even in peace time. 
Such reconnaissance can be carried out both ashore and at sea, and, in the former 
case, on targets either in the terrain or at sea. 
As a tactical aid, ground photo reconnaissance has been assigned certain 
definite tasks. One of these is fast reconnaissance with patrols behind the enemy 
front with the purpose of objectively ascertaining what an observer sees at a 
certain moment. Measurements can then be taken on the photos and the various 
targets such as artillery of different types and calibres, tanks, etc. carefully iden- 
tified by the photo-interpreters of the unit. It is worth mentioning that the 
terrain reproduced in the ground photos can often be localized accurately by 
comparing it with aerial photographs of the area in question. 
Another task for the tactical photo reconnaissance within the battle area is 
to photographically reconnoiter targets which cannot be fixed through mere 
visual reconnaissance or through field-glasses. Such detailed photo reconnais- 
sance is carried out on the front lines with the intention of ascertaining the types 
of the enemy fortifications, and revealing whatever camouflage may exist. 
Through keeping a continuous photographic watch over one and the same 
sector of the front, it is possible to ascertain what changes may be made in the 
enemy terrain, for example, newly erected, well camouflaged emplacements and 
machine-gun nests, etc., which, otherwise, might not be observed. These photos 
are also presented as stereo panoramas, and used at observation and fire- 
regulating stations and command stations and artillery centers respectively 
as a basis for making out reports and issuing orders and directing fire. Target 
fixing is made very much easier if ground photographs are available. 
In mobile fighting within one’s own area, panorama photos are used in a 
corresponding way for observation and fire regulating purposes, when keeping 
watch, report and order issuing, etc. but with the difference that the photos 
are taken over the battle area to-be, in front of the planned new positions. 
Ground photographs can be of great value for fire-directing purposes of 
mortar and artillery units. Panorama photos with coordinate scales already in 
the negative are most suitable for this, and should be taken when the situation 
permits. 
Ground photo reconnaissance within the battle area, is, however, carried 
out not only by day, but even by night; in the latter case, especially to accurate- 
ly fix the positions in the enemy lines of machine-guns and other automatic