The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B7. Beijing 2008 
Figure 3. April 19, 2007, 09:54 h, nadir, flying height 2500 m 
above ground, visibility 10 km, without BRDF correction (left 
to right): uncorrected pseudo reflectance, modified Song-Lu- 
Wesely method, Angstrom method. 
—♦—alpha N00 2500m 180° 
--•—alpha N00 2500m 0“ 
alpha N00 1500m 180° 
alpha N00 1500m 0° 
-»—ground measurement 
wavelength [nm] 
-rho_cwN00 2500m 180° 
rho_cwN00 2500m 0° 
rho_cwN00 1500m 180° 
rho_cwN00 1500m0° 
-ground measurement 
400 500 600 700 800 900 
Figure 5. March 28, 2007, 09:58 h, nadir, flying height 2500 m 
above ground, visibility 20 km, without BRDF correction (left 
to right): uncorrected pseudo reflectance, modified Song-Lu- 
Wesely method, Angstrom method. 
—•—alpha N00 2500m 181° 
-•-alpha N00 2500m 1° 
alpha N00 1500m 1° 
*• alpha N00 1500m 101° 
-»—ground measurement 
wavelength [nm] 
—rho_cw N00 2500m 181° 
—e— rho_cw N00 2500m 1° 
rho_cw N00 1 500m 1° 
rho_cw N00 1500m 181° 
-»—ground m easurement 
wavelength [nm] 
wavelength [nm] 
-angstromN00 2500m 180° 
angstrom N00 2500m 0° 
angstrom N00 1500m 180° 
angstrom N00 1500m 0° 
ground measurement 
angstrom N00 2500m 181° 
•— angstrom N00 2500m 1° 
angstrom N00 1500m 1° 
angstrom N00 1500m 181° 
»-ground measurement 
400 500 600 700 800 900 
wavelength [nm] 
wavelength [nm] 
Figure 4. April 19, 2007, nadir view, grass target on 4 images in 
opposite direction (heading 0° and 180°) and flying height 1500 
m and 2500 m above ground, visibility 10 km (top to bottom): 
uncorrected pseudo reflectance, modified Song-Lu-Wesely 
method, Angstrom method. 
Figure 6. March 28, 2007, nadir view, grass target on 4 images 
in opposite directions (heading 1° and 181°) and flying height 
1500 m and 2500 m above ground, visibility 20 km (top to 
bottom): uncorrected pseudo reflectance, modified Song-Lu- 
Wesely method, Angstrom method.