The MERTIS instrument design is based on a highly integrated and miniaturized concept, featuring low mass of only about 3kg and a sophisticated design developed by the DLR Institute of Robotics and Mechatronics, Department Optical Informationsystems.
MERTIS is an imaging spectrometer obtaining hyper-spectral data in the thermal IR wavelength range with a medium spatial resolution to determine the mineralogical composition of the Mercury’s surface. An un-cooled micro-bolometer array provides spectral separation and spatial resolution according to its 2-dimensional shape and operates close to room temperature. Sharing the same optical path a pushbroom micro-radiometer is integrated allowing measurements of the Mercury surface temperature and obtaining the thermal inertia of the regolith.
The operation concept principle is characterized by intermediate scanning of the planet surface and 3 different calibration targets – deep space and two on-board black body sources.
The general instrument architecture comprises two separate parts - the Sensor Head including optics, detectors, shutter and proximity sensor electronics and the Electronics Unit containing the instrument control unit, power supply as well as calibration sources. This highly integrated measurement system is completed by a pointing/scanning device which orients the optical path to the planet view and the calibration targets.
DLR develops the system design, integrates the instrument sub-units and verifies the overall performance based on laboratory investigations including instrument calibrations. The MERTIS development is done in close cooperation with scientific and industrial institutions, the Principle Investigator of the University - Münster, the DLR Institute of Planetary Research - Berlin, Kayser Threde – Munich, Astrofeinwerktechnik – Berlin, the Polish Space Research Center - Warsaw and the Ingenieurbüro Ulmer – Frankfurt/Oder.