Design And Analysis Of The Multispectral Remote Sensing Imager

Formosat-5 is the first self-reliant remote sensing satellite of Taiwan. Remote sensing imager (RSI) is the primary payload on it. RSI is a multispectral imager which contains one panchromatic band with 2-meter ground sampling distance (GSD) and four multispectral bands with 4 m GSD. Optical design of the RSI is performed to meet the requirements. Cassegrain type of optical design has been selected. Several designs have been studied to reduce the alignment sensitivity and the effect of the orbital deformation according to the size restriction. The truss configuration of structural design has been selected, and an M2 support ring is designed to support the secondary mirror. Following tolerance, finite-element, and thermal analyses are performed. The tolerance of radius of curvature is one thousandth of radius. The first mode of the telescope is 81.3 Hz when the total mass is 85.7 kg, First mode of vibration occurs along the lateral direction that is perpendicular to the launch axis. TRASYS and SINDA model of RSI have been established for thermal analysis. Both hot and cold cases have been studied. The result shows that 39.4W of heater power is required in cold case.