2. The service (2013)
Dataset and pre-processing:
![]() |
Fig. 1: input datasets. RGB and Infra-Red composite color images in June and July 2005. |
Pre-processing:
- Precise geo-referencing by matching to Landsat imagery
- Atmospheric correction
Method:
![]() |
Fig. 2: Root Mean Square Deviation image (or sum of the quadratic difference bands between bands). The changes are given by the highest values in RMSD. |
The changes due to the deforestation must be distinguished from the one due to other origins, such as:
- clouds, snow, haze, fog...,
- cloud or orography shadows,
- land use/cover changes
- changes of types of cultures
... in order to obtain a map where red pixels depict the area where a doubt has been raised on the ground exploitation, i.e. where forest might have been destroyed to be replaced by crops, as depicted in the following picture:
![]() |
Fig. 3: Remaining suspect areas after image processing: These selected areas are worse sending a ground station mission. |
Status of the development: the service is going to be tested by Primer users by the end of the first trimester 2012.
Notes: The precision of the ortho-rectification is 90 m, which corresponds approximately to one third of the spatial resolution of MERIS => this is the most part of the 4 hours of time required by CATENA to compute the result.