High Precision Optical Metrology System for the SMART-2 mission as precursor for the DARWIN Satellite Constellation

摘要

The presented paper reports on a conceptual design of a High Precision Optical Metrology (HPOM) system for SMART-2 with the emphasis of establishing and controlling the distance between the satellites. SMART-2 serves as a pre-cursor technology mission for DARWIN where critical technologies will be demonstrated. An overview about the DARWIN and SMART-2 mission and requirements is given. The HPOM system must take over from the Radio Frequency (RF) system at an inferometer arm difference of some cm and must establish and control an arm difference of smaller than 5nm at a 3dB bandwidth of 100Hz. A cascaded metrology system has been developed using different optical metrology methods such as time of flight, dual-wavelength and white light interferometry within one system to meet the ambitious requirement.