-— A E 
  
Figure 6. VNIR sensor image 
  
  
  
  
  
   
    
EE i ccm 
Figure 7. The full screen of VNIR program 
Spectral information was able to be extracted by pixel from 
photographed imagery by using ENVI software. Spectral 
information, which was shown on the spectral profile window 
as shown in Figure 8, was saved in ASCII file form and then 
processed in Excel with reference to the reflectance of 99% 
white pannel like the case of GER-3700 
Figure 8. Spectral Profile 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
  
-— Sth22Map 
-—— Sih27Map 
ses Sth:37Map 
- Sth:38Map 
50% 
75% 
Reflectance 
  
ANS #55 585 E 293 253 253 
Wavelength(nm) 
  
Figure 9. Spectral characteristics of reflectance panels and 
concretes extracted by VNIR camera 
Figure 9 shows reflectance according to wavelength for four 
different specimens and four different reflectance pannels. 
Reflectance rates were computed by dividing into the value of 
99% reflectance pannel. In interior experiment, the results of 
the spectrometer showed more consistent reflectance curve in 
SWIR range than VNIR range and appeared high reliability 
compared with those of the VNIR hyperspectral camera. 
3. EXPERIMENT ON ACTUAL CONCRETE 
STRUCTURES 
The GER-3700 spectrometer and the VNIR camera were 
applied to the actual concrete structures such as a bridge slab 
and pier in a road construction site. The experimments were 
conducted for the upper side of pier of Daejongchun Bridge and 
the decks surface of Yangbuk Bridge. 
The result values of GER-3700 shows high absorption at 
1950nm against those of interior experiment on concrete 
specimens. However it can't be considered as an error because 
all of spectral data which were collected in the construction site 
appear high absorption or reflectance in 1950nm. And results in 
VNIR (visible and near infrared) wavelength range show almost 
similar pattern with those of interior experiment. 
    
  
Figure 10. Data Collection using GER-3700 on Yangbuk 
Bridge