ate tiepoint 
Juergen Oberst 
  
Table 4: 1 - o residuals after least-squares fit 
  
  
  
  
  
  
  
nages were GENE 
Image Manual Automated Autom. Measurements 
File Measurements Measurements after geom. correction 
ge area mj 
ito a mask. starcl013 1.1633 [15] 0.9018 [18] 0.6265 
ication was starcl021 0.7952 [16] 0.7970 [19] 0.3516 
Ve] / Ver, starcl071 0.8417 [15] 0.9097 [24] 0.6206 
mputed by starcl091 1.2454 [16] 0.8844 [27] 0.5683 
ues for the starcl141 0.8812 [14] 0.9809 [31] 0.6136 
starcl131 0.9322 [19] 0.7936 [26] 0.3932 
starcl151 0.9356 [16] *) 
(4a) starcl191 0.9071 [16] 0.6885 [22] 0.3268 
(4b) starcl201 1.2976 [18] *) 
(4c) nav04110 2.2501 [8] 0.5707 [8] 0.3456 
nav04112 5.4750 [12] 1.0577 [6] 1.0238 
nav04113 0.8481 [22] 0.9317 [19] 0.5628 
he star was nav04210 0.9254 [9] 0.6075 [14] 0.4356 
accuracy. nav04212 1.0809 [13] 0.8478 [13] 0.4617 
coordinates nav04213 0.8353 [21] 0.6735 [14] 0.4688 
ir positions nav04308 0.9462 [12] 0.7266 [13] 0.3443 
 Tespective nav04309 0.8798 [22] 0.3711 [19] 0.3871 
nav04408 0.8682 [13] 0.4257 [12] 0.4461 
nav04409 0.9188 [21] 0.5150 [13] 0.4270 
ogram was 
bright right Mean**) 1.07 0.75 0.47 
s were used 
€ shown in Numbers in brackets give the number of identified stars 
reduced to 
1rements is *) automated matching failed (very smeared images with overlapping star trails) 
acy of the sek) root mean square (after eliminating obvious outliers) 
of smeared 
1131, Fig. 
+ + 
== ^ 
y distortion “A 
ement (Fig. yf 
itions using 
0.47 pixels, AA Af 
tes that the "s d 
ght images; v : 
amera focal n s + 
nd which is s + 
nal value of x s 
ify possible T 
1 fits were : —— Ae 
siduals with te + acc Hl : 
Patter in the 
  
  
  
  
  
  
  
Fig. 6: Vector plots showing offsets between nominal and measured position of stars in the 1024 x 1024 image. Data 
from all 19 star images were combined. The plot shows data residuals before (left) and after (right) the best-fit 
distortion model (equations 1-3, Table 3) is applied. Compare magnitude and overall shape of the distortion pattern 
before and after the fit with the laboratory data in Fig. 3. The stars are unfortunately not evenly distributed over the 
image area. The lengths of the arrows are exaggerated by a factor of 50, as in Fig. 3. 
two sets of 
ple position 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000. 227