ARCADE, A linear guide with nanometer accuracy

ARCADE (ARistoteles CAlibration DEvice) was developed for the on-board calibration of GRADIO, which is the core instrument of the Aristoteles satellite. GRADIO will measure the Earth gravity field with an accuracy of 5.10-5m/s2 and a resolution of 100 km x 100 km at the Earth surface. GRADIO consists of four accelerometers mounted on a square plate of 0.9 m x 0.9 m. The accelerometers are permanently calibrated by generating continuous (sinusoid) vibrations outside the measurement bandwidth. ARCADE is a specially developed linear guide system based on elastic elements. In ARCADE a mass of 0.76 kg moves with an amplitude of 3 mm and a maximum lateral deviation of 15 nm, while the required power is less than 2.5 Watt.