International Archives of the Photogrammetry, Remote Sensing 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Point dN(m) | dE(m) | dR(m) | dh(m) 
RN02 0030 | 0.215 | 0216 | 0.085 
RN03 -0.215 | -0019 | 0.216 | 0.053 
RN08 -0.006 0.136 | 0.136 | -0.050 
RN09 -0.001 0.121 0.121 | -0.009 
RN12 0.321 -0.120 | 0.343 | -0.168 
RN14 -0.227 0.315 0.388 | -0.133 
RN21 -0.032 -0.397 | 0.398 | 0.013 
RN23 -0.169 1 -0:130 1 9.213 0.192 
mean -0.044 0.015 | 0.254 | -0.002 
s.d. 0.164 0214 | 0.102 | 0.100 
  
Table 1. LIDAR verification 
4.2 Triangulation 
Firstly, utilizing intensity image (Figure 5.3) and aerial image 
(Figure 5.b), thirty-five details that were identifiable in both 
images and that were in the necessary geometric position to 
carry out triangulation were selected, as shown in Figure 4. To 
meet the search criteria in the original Laser Scanner data, these 
points were always defined on the top of the objects selected. 
Utilizing the program ENVI 3.4 and the intensity image, the 
planimetric coordinates (approximate) of the points selected 
were extracted; 
- employing the same procedure used in item 4.1, the 
planimetric coordinates of thirty five points selected were 
determined in the original text file proceeding from the Laser 
Scanner; 
- exemplifying the procedure for Point 8, of approximate 
coordinates E — 677677.76 m and N = 7184398.63 m, one has 
in Table 2 the selected points in a 1 m ray circle. 
  
  
  
  
  
  
  
  
  
  
Point E(m) N(m) h(m) d(m) 
8.1 677677.540 | 7184398.420 | 924.310 | 0.304 
8.2 677678.230 | 7184398.830 | 923.660 | 0.511 
8.3 677677.210 | 7184399.140 | 914.750 | 0.750 
8.4 677678.520 | 7184398.320 | 923.560 | 0.821 
8.5 677677.690 | 7184397.800 | 924.470 | 0.833 
8.6 671611.660 | 7184399.600 | 919.830 | 0.975 
  
  
  
  
Table 2. Original coordinates researched for the Point 8. 
Table 2 shows that point 8.1 meets the criteria of proximity and 
highest altitude. 
Out of the group of thirty-five points, nine points of planimetric 
control in the periphery of the block were selected, twenty-one 
of altimetric control and five of verification. Employing the 
program ENVI 3.4, the manual reading of the photogrammetric 
points selected in the thirteen images taking part of the block to 
be triangulated was performed. The coordinates were obtained 
in the digital system and next transformed into the 
photogrametric system with proper corrections of systematic 
errors. Finally, the processing of triangulation with the program 
BundleH was conducted. As far as the ground control points 
   
  
and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004 
existing in the triangulated block are concerned, it was decided 
that the control points planialtimetrically constrainted occupied 
the periphery of the block, so as to be minimum in number and 
to leave the biggest area possible in the interior of this block 
occupied by point with altimetric constraint. 
The final distribution of the triangulated points and of 
verification (without any constraint), may be observed in Figure 
4. 
  
    
NORTH 
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FREE POINT —— ap NA 197  Z CONSTRAINT 
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STRIP 1 198 ‚MAGES 
; 199 
   
. Figure 4. Triangulated Block. 
     
   
  
International Archi 
POINT 8 
(a) 
Figure 6 — (a) LID 
central area); (b) det 
detail of the Point 8 
The results obtaine 
within the precisio: 
observations and fi 
Firstly, a global an 
considered utilizing 
on the a priori (1.0 
was verified that t 
conducted are all be 
the terrain. Compa 
altimetric constrain 
triangulation and the 
is verified in Table 
meters, with standarc 
of the points tested 2 
cm and 10094 of th 
displays the results o 
case, the planimetric 
significant considerir 
standard deviation o 
the planimetric accut 
is around 75 cm and : 
6. CONCLUSK 
The results obtained 
to the following conc 
- the methodology er 
and determination « 
control for triangulati 
- low-cost digital c 
aerophotogrammetric 
- the utilization of nor 
I$ promising for futur 
- the utilization of th: 
consistent and efficier 
- the integration of I 
with small-format dig 
considering the prog 
sensors of these came 
surveyed with LIDAR