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ry, agriculture, engineering projects, architectural works, archeology, the research 
of the distortion of buildings, in astronomy etc. In order to solve such diverse 
problems different instruments and methods, which satisfy the requirements of 
accuracy, economy and efficiency, are used. 
Airphotography is done from airplanes of different speed. The flight height 
is 200 meters and more. For photographing the terrain soviet cameras T. E. 1 
are used. The picture size is 18 X 18 cm and the focal lengths are 500, 350 
200, 100, 70 and 55 mm. The angle of view of cameras varies from 20° to 136°. 
In these cameras the flattening of the film during the exposure time is secured 
with great accuracy. The flattening of the film is checked. 
The connection of the mechanism of the magazine and the shutter is ac 
complished by electrical means. In this way the camera T. E. differs from 
other aerial cameras and this is the cause of its reliability and of its having 
very few movable details. The photographic lenses used in T. E. cameras are 
of the Russar type. Their characteristics are: a large angle of view, optical 
distortion 0.02 mm and a resolving power approximately 30 lines per mm. The 
change of luminance from the central part of the picture to its marginal parts 
is proportional the cosine of the angle of incidence taken in power of 2.5, and 
not in the fourth power, as is due to the Lambert’s law. 
For photographing aerofilms of 60 meters length are used. The resolving 
power of the light-sensitive layer is about 100—120 lines per mm. The pictures 
are black and white, achromatic, colored or spectro-zonal, as they are called 
in Russian. The latter are pictures made on special color-films, which do not 
render the object-image in natural colors. The use of convergent photography 
is quite restricted. 
In addition to the camera some airborne instruments are used. They are: 
the radio-altimeter RWTD 2 and the statoscope. The radio-altimeter permits 
to determine the distance from the airplane to the nearest point of terrain with 
an error of about 1 meter. The determination of the absolute height of flying 
is done indoors by means of specifical stereo-grids. The readings of the radio 
altimeter are recorded by an additional photo-camera, which is synchronized 
with the aerial camera. 
The differences of the flying-height are obtained barometrically with the aid 
of aneroids or statoscopes. The error of the flight-height-differences determina 
tion in fine weather conditions is about 1 meter. The having of the radio- 
altimeter records enables us to get the relative elevations of the terrain along 
the strip. So for the airsurveying in USSR such things are characteristic: the 
tendency of airborne fixation of the elements of exterior orientation, the 
using of wide-anglers and the high quality of images. 
Le Prof. Dr. M. Konchine donne quelques renseignements sur le développement en Union 
Soviétique de la photogrammétrie aérienne et sur ses diverses applications. Certaines de ces 
informations sont très vagues. Il précise cependant que les chambres de prise de vues T. E. 
(Topographique Electrique) ont un format 18 X 18 cm et des tirages de 500, 350, 200, 100 et 55 
mm, correspondant à des angles de champ allant de 20 à 136°. Il indique que la planéité du film 
est contrôlée. Les objectifs Russar à grand champ ont une distorsion de 2/100 mm et un pouvoir 
résolvant de 30 lignes par millimètre. La loi de l’éclairement est en cos 2 > s 0, 0 étant l’angle de 
champ. Les vues sont prises sur film de 60 mètres, ayant une définition de 100 à 120 lignes par 
mm. Deux instruments aéroportés sont utilisés: le raclio-altimètre RWTD et le statoscope. Le 
radio-altimètre détermine la distance de l’avion au point du terrain le plus proche avec la précision 
du mètre. L T n couple stéréoscopique de réseaux quadrillés permet la détermination au laboratoire 
de l’altitude absolue. Des anéroïdes de précision ou des statoscopes mettent en évidence des varia 
tions d’altitude d’un mètre. Les trois traits caractéristiques de la photogrammétrie aérienne en 
Russie sont: la tendance à l’enregistrement des éléments d’orientement externe au moyen d’ins 
truments aéroportés, l’emploi d’objectifs à très grands angles de champ et la haute définition des 
photographies. 
2 RWTD is the abbreviation of Radio Altimeter Topographical Decimal Wave lengths.