International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 International 
  
image of the water depth at the same resolution of the 
QuickBird data. Several tests have been performed into five 
different test sites (S.Erasmo littoral, Treporti canal, S. Felice 
canal, Canesa canal and Bari canal) where 18 radiometric 
transects were traced to study the lagoon bathymetry. For every 
testing site, depths points (DP) were estimated from the 
QuickBird data using the SGA algorithm described in (2.2). A 
final bathymetry estimation was obtained interpolating all the 
DPs extracted. 
Data on suspended sediment concentration and bottom 
composition materials were not available for reference. 
Depth (m) 
  
Figure : 
4.2 Treport 
Four radiom« 
traced at Tre 
  
Figure 2. Radiometric transects at S. Erasmo littoral with real bathyme 
lagoon depths overlayed. for the transe 
8 show result 
  
  
  
Real batymetry 
  
  
  
  
Depth (mj 
^ 
8 
      
Figure I. QuickBird multispectral image of the Lagoon of auixo 
Venice (May 16, 2002; 10:05:40 GMT). RGB composition. 
  
Distance (m) 
Figure 3. Bathymetry estimation at S. Erasmo littoral 
(radiometric transect nr.1). R°=0.96 
4. RESULTS 
4.1 S. Erasmo littoral 
Three radiometric transects (transects nr.1, 2 and nr.3) were D 
  
  
  
  
  
  
  
traced at S. Erasmo littoral (Figure 2). For transects nr.1 and gan Fiere. R 
nr.2 the correlation between the real bathymetry (derived from 20 5 * 
the sounding points) and the computed bathymetry with the on Ee 
SGA algorithm showed a very high correlation (R?-0.96 for ax E 
  
  
transect nr.l and R/-0.94 for transect nr.2), while for the 
transect nr.3 a correlation of 0.89 was obtained. Figures 3, 4 
and 5 show results. 
000 rr 
Depth (m) 
& 
= 
€ 
  
4,000 ++ 
  
  
-10,000 
Depth (m) 
Distance (m) 
Figure 4. Bathymetry estimation at S. Erasmo littoral 
(radiometric transect nr.2). R^-0.94 
  
Figure 7. B 
96