The Stereo Channel (STC) is a double wide-angle camera developed to be one of the channels of the SIMBIO-SYS
instrument onboard of the ESA BepiColombo mission to Mercury. STC main goal is to map in 3D the whole Mercury
surface.
The geometric and radiometric responses of the STC Proto Flight model have been characterized on-ground during the
calibration campaign. The derived responses will be used to calibrate the STC images that will be acquired in flight. The
aim is to derive the functions that link the detected signal in digital number to the radiance of the target surface in physical
units.
The result of the radiometric calibration consists in the determination of well-defined quantities: i) the dark current as a
function of the integration time and of the detector temperature, nominally fixed at 268 K; ii) the Read Out Noise, which
is associated with the noise signal of the read-out electronic; iii) the Fixed Pattern Noise, which is generated by the different
response of each pixel; iv) once these quantities are known, the photon response and the Photo Response Non-uniformity,
which represent the variation of the photon-responsivity of a pixel in an array, can be derived.
The final result of the radiometric calibration is the relation between the radiance of an accurately known and uniform
source, and the digital numbers measured by the detector