Beutner, Sabine 
  
have a width of about 10 cm (compare Figure 1), could still be distinguished.The image overlap is 60% in both direc- 
tions. The control points are very sparse and signalized in Nasca and Palpa, while in San Ignacio natural features have 
been used. All GPS coordinates have been transformed into the Peruvian system UTM Zone 18, which is also the basis 
of the national topographic maps 1:50 000. 
There are aerial images around from previous missions of the SAN (Servicio Aerofotografico Nacional), but most of 
these blocks were flown for agricultural and land development purposes and cover mainly the valleys, which do not con- 
tain geoglyphs. Our oldest set of images dates back to 1944 and shows clearly the geoglyphs in a much better condition 
than today. Also, attempts have been made to take 70 mm format photos from a balloon and and a small airplane (Aveni, 
1990) over the pampa of Nasca, but these efforts failed because of either uncontrollable conditions for the balloon or too 
small image scales (1:24 000) for the airplane photos. Our photographs constitute the first complete set of aerial images 
over these areas at the right image scales that can be used for stereo processing. 
  
  
AB s nn 
  
Figure 3. Part of an aerial image of the Palpa block 
  
  
  
  
  
  
  
  
  
  
  
  
  
Area image number of planned C (color) or number of 
acquisition images image scale B/W (black and white) control points 
Nasca Apr/Mai'97 309 1:10 000 C neg 11 (signal.) 
Mai'98 309 1:10 000 B/W pos 0 
Palpa Apr/Mai'97 134 1:5 000 C neg 8 (signal.) 
Mai'98 134 1:5 000 B/W pos 0 
San Ignacio Mai’98 189 1:5 000 B/W pos 9 (natural) 
  
  
Table 1: Project parameters for Nasca, Palpa and San Ignacio 
3 PHOTOGRAMMETRIC DATA PROCESSING 
In the following we will only report about the processing of the block Palpa. This one had priority because all the excavæ 
tions took place in the Palpa area. Currently the block San Ignacio is in work. 
3.1 Aerial Triangulation 
  
Since it was anticipated that the automated measurement of tie points would cause serious problems because of lack of 
good texture in many regions, we decided from the very beginning to measure manually on the Analytical Plotters AC 
  
56 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 
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