-— [Aa 
One of the centres of archeological aerial photo inter- 
pretation is the Hungarian National Museum. So far, 
significants results have been achieved in a research 
project involving the earthwork trenches discovered in 
the Great Plains. As thelr greater part had been comple- 
tely destroyed, a considerable section of about 120 km 
in length could be detected only by aerial photographs. 
At the same time another trench System was excavated in 
the western part of the country, on which rather un- 
certain historical data had been available so far. Here 
aerial photographs taken at a flying height of 5000 to 
4000 m were used, which revealed the 12 to 20 m wide 
trench lines quite clearly, illustrating the ploughed-in 
banks in the form of light soil Strips whereas the for- 
mer trenches as parallel dark lines. 
Such photographs have been similarly exploited with much 
success in other archeological projects as well, like in 
searching for the county seats of the 11th centruy, 
represented by 2-3 ha area earthwork fortifications that 
time. Their complete trench system could be clarified by 
these photos. The same method was adopted in looking for 
the original site of the village settlements belonging 
to the county capitals. 
Significant results have been achieved in the hilly 
regions where the thinner humus layer did not cover 
completely the archeological traces. Many findings could 
be discovered through aerial photographs, such as the 
tombs and graves in Szâszhalombatta, or the wall ruins 
of the Roman turret near Hatvan, buried a long time ago, 
etc. 
3. Photogrammetric research in Hungary 
As fundamental research institutions in Hungary, two 
establishments can be mentioned in the field of photo- 
grammetry: the Institute of Geodesy and Geophysics, 
Sopron, of the Hungarian Academy of Sciences which is 
dealing mainly with theoretical research problems, and 
the Surveyor Institute of the National Land and Cartog- 
raphy Office which is the authority mainly of applied 
research projects. Research is carried on, furthermore, 
by certain university and college departments, geodetic 
and cartographic enterprises, and some specialized 
organizations.