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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
aerial photographic surveys to study details of ice-drift in the open sea. 
This is quite feasible through graphical reconstruction of the original form 
of ice fields by the mosaic method. The processing of each mosaic aligned with 
a respective photograph to close the mosaic with the unbroken part of the ice 
field will enable us to obtain families of vectors characterising the direction and 
the path traversed by certain characteristic points of the mosaic (fig. 11). 
By summazising the vectors of one family and determining the resultant, we 
can transfer this resultant onto a report chart of the aerial ice patrol. Several 
such resultants in combination with the line of general drift, plotted on the 
chart according to the data provided by radio survey stakes on ice-floes, will 
reveal the most minute details of the drift and help to give a better explana 
tion of its mechanism. 
This is necessary if only for the reason that up to now it seemed impossible 
to employ aerial photographs in the study of ice-drift in the Central Polar 
Basin. The aerial methods used today for such studies [8] are effective only for 
observations in the coastal area, not more than 100 km off shore. 
We hope in the near future to obtain tangible proof of the above thesis. 
References 
1. Avgevich, V. I. Air Survey and Stereophotogrammetry. The collection of “The Soviet 
Geography” Geographgiz, Moscow, 1961. 
2. Avgevich, V. I. Interpretation of the Snow Cover of Sea-Ice on Aerial Photographs and 
Further Prospects for the Use of Aerial Photographic Survey in the Science of Snow. 
Collection of the Geographical Institute, U.S.S.R. Academy of Sciences “The Role of 
Snow Cover in Natural Processes”, Moscow 1961, U.S.S.R. Academy of Sciences Publish 
ing House. 
3. Avgevich, V. I. New Trends in the Use of Aerial Photograph Survey and Photogram- 
metry in Hydrological Investigations of Ice Regimes of Seas and Rivers. Paper submitted 
as Doctor’s thesis. Geographical Institute, U.S.S.R. Academy of Sciences, Moscow 1956. 
4. Gonin, G. B. Interpretation of Ice on Aerial Photographs Obtained with a Slit Camera. 
“The Problems of the Arctic”, Leningrad 1957, No. 2. 
5. Gonin, G. B. Evaluation of Hummocky Aggregations by the Statistical Processing of 
Aerial Photograph Survey Materials “The Problems of the Arctic and the Antarctic”, 
Leningrad 1960, No. 3. 
6. Loshchilov, V. S. The Method of Underwater Stereophotography in Oceanographic 
Explorations. “Problems of the Arctic”, Leningrad 1957, No. 2. 
7. Rekhtzamer, G. R. The Methods of Aerial Photograph Survey and Interpretation of 
Aerial Photographs of Sea Ice. “Transactions of the Leningrad Hydrometeorological 
Institute”, Leningrad 1961, Issue 10, Coll. I. 
8. Rekhtzamer, G. R Determination of Ice Drift by Aerial Methods. Ibid.