ate first 
position 
manual 
eration. 
s of the 
gs from 
ringing 
regular 
ta bases 
n to the 
tion for 
nmetry, 
ational. 
ges and 
Romuald Kaczynski 
COMPARISON OF SEMI - AUTOMATIC AND AUTOMATIC DIGITAL AERIAL 
TRIANGULATION 
Romuald KACZYNSKI*, Jan ZIOBRO** 
Institute of Geodesy and Cartography, Warsaw, Poland 
*rom@igik.edu.pl 
**ziobro@igik.edu.pl 
Working Group III/2 
KEY WORDS: Aerial triangulation, Automation, Accuracy 
ABSTRACT 
Two aerial blocks (93 and 56 photos) taken in different scales and of different qualities have been tested at the Institute 
of Geodesy and Cartography in Warsaw with two methods: semi-automatic with the use of ISDM INTERGRAPH and 
automatic with MATCH-AT Inpho. The results of comparison of two methods concerning their accuracy and usefulness 
in case of different quality of aerial photographs are presented. 
1 INTRODUCTION 
The comparison of results of Automatic Aerial triangulation with semi-automatic triangulation was the main task of the 
work. The comparison has been done on the basis of two blocks of aerial photographs taken without signalized GCP's. 
Independent check accuracy of aerial triangulation has been done. Also exterior orientation parameters have been 
compared. The usefulness of applying Automatic AT using duplicate diapositives with poor radiometric quality instead 
of originals of aerial photographs has been tested. Moreover, the study area was densely populated and covered by lush 
vegetation. 
Two blocks have been used with natural GCP's identified with accuracy about 0.5 pixel and measured in the field. 
Aerial photographs have been scanned on PhotoScan PS-1 Zeiss/INTERGRAPH with pixel size 22.5 um including 
photoalignment and compression by JPEG. Only Red band has been used for digital aerial triangulation. 
2 DATA USED 
Block No.1 consisted of town and residential area. As the LMK Zeiss camera was used - radiometric and geometric 
quality of the photographs were good. There were 17 natural, not signalized GCP's and 44 check points which have 
been identified and measured in the field with accuracy in X and Y - 9 cm, Z- 15 cm. The 93 photos were taken in 9 
strips with end lap 60% and side lap 37 %. As the orthophoto maps of town were to be elaborated - LMK Zeiss camera 
with focal length 305 mm has been used. 
Block No.2 was a part of a larger block, where photographs have been taken N-S/S-N in the framework of Phare project 
conducted in Poland in last few years. The strips have been taken in different times of the day. Duplicate diapositives 
that have been scanned were found to have radial deformation of up to 19 um. Leica RC-20 camera has been used with 
focal length 152 mm and with end lap 60 % and side lap 30%. The block consisted of 56 photos taken in 4 strips. Block 
No.2 consisted of five towns and partly covered by forest. There were 16 natural GCP's and 16 checkpoints. 
Coordinates of all of these natural points have been identified in the field and measured by GPS technique with overall 
accuracy X, Y about - 45 cm and Z about - 30 cm. 
All photographs have been scanned on the PS-1 PhotoScan Zeiss/INTERGRAPH with photoalignment, compression by 
JPEG (Q=25) and with pixel size 22.5 um in Intergraph format. Only Red band was used for digital aerotriangulation. 
Description of the blocks is shown in Table 1. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000. 457