For this purpose some hyperspectral sensors have been utilized
over San Rossore among them MIVIS, VIRS-200 and the recently
developed HYPER/SIM-GA, whose main characteristics are reported
in Tables 4, 5 and 6 respectively. MIVIS is a whisk-broom imaging
spectrometer operating outside the atmospheric absorption bands
from the visible to the short wave infrared (0.4–2.5 mm) and into
the thermal infrared (8.2 12.7 mm). VIRS-200 is a push-broom imaging
spectrometer utilizing 20 narrow spectral bands selectable
among 240 placed between 0.4 and 1.0 mm. The newly developed
HYPER/SIM-GA is a system consisting of two push-broom imaging
spectrometers operating in the visible and near infrared with 512
spectral bands, and in the short wave infrared with 256 bands.
Due to the advanced characteristics of these systems and the
high accuracy of the data that have to be acquired by these instruments,
careful calibration has to be performed in the laboratory
before and after each campaign. If this is not possible, the calibration
together with the validation activity must be performed in the
field during the sensor overflights. For these activities ground
measurements are needed as well as some laboratory measurements
performed on collected samples. In addition atmospheric
measurements are required to improve the accuracy of the