Under the European
Unions field crop subsidy scheme each Member State is required
by the existing regulations to check 5% of the subsidy claims. In
Belgium the Ministry of Agriculture uses a computerised system to
check the acreages for which subsidies are claimed with data obtained
by remote sensing (satellite imagery and aerial photographs).
A geographic database
of the land under cultivation has been compiled from orthorectified
aerial photos. This database can be used to check the reported acreages.
satellite images taken at different times during the vegetative
growth cycle are classified automatically by their spectral signatures.
This makes it possible to identify the most likely crop class for
each plot of land. This result is then checked by photo interpreters
before going out into the field. In this way, the field checks can
be limited to dubious or contested cases.
The subsidies are checked mainly with the
help of remote sensing. Without satellite imagery it would be financially
and materially impossible to check the farmers declarations
effectively and, above all, within the required deadlines.