8. Ground Truthing
In the previous page I have marked some zones (from 1 to 5), it is necessary to
validate them by a direct visual control noting if the vegetation status described in
the map is correct.
Especially zone 4 can be the result of an erroneus exposition of the picture or due
to high sun reflectance when the airplane was turning.
9. Ground Truthing Results
Zone 1: The color of the leaves light green and leaves quantity is a
bit less then normal
14. Ground Truthing vs Map, possible
problems
The ground controls have detected some inconsistencies versus the map prepared:
- either zone 4 and 5 have been swapped as pictures and description or the effect
of the sparse pictures and lack of vignetting correction has created an erroneus
Map for those part of the parcels.
More sofisticated analysis on the pictures has detected a sensible vignetting
Problem in NIR, due mainly to filter positioning and optical zoom.
See the following example where i have put emphasis on the vignetting problem:
→ with adequate
Processing →
(before and after)
15. Optical/Lens Distorsion Correction
The image was used for
calculating the K1,K2,K3
parameters for lens distorsion
correction. Vignetting is strongly
visible due to white balance
settings
