Optomechanical Design of Fragile Multispectral Camera for Remote Sensing Satellite

Abstract

The report furnishes the concurrent design approach to arrive a configuration of multispectral camera having requisite optical performance with minimization of mass. The multi spectral camera consists three bands with modular configuration having individual optics, detector assembly and electronics separately for each band. This report consist of detailed design and analysis of all the components of multispectral camera under launch, on-orbit and storage loads. The report also highlights on the design requirements for all the components of multispectral camera. Optomechanical lens assembly for spectral imager contains ten brittle lens elements made out of schott glass including one thermal filter made out of fused silica. Design and optimization have been carried out of the structure, which is held in various lens elements in proper axial and radial alignments under various environmental conditions. Each of the three bands has a separate and identical detector head assembly (DHA), which essentially consists of a linear array charged coupled device (CCD) and a printed circuit board (PCB) mounted on mechanical housing. The design modification of lens mount and CCD mount is carried out to minimize interfacial stresses, which in turn enhances the storage life of the components. The strength of all optical lenses has been computed analytically and co-related with literature. Detailed design and structural analysis of full lens camera assembly are carried out to meet the design requirements with minimum structural weight and high stiffness using finite element analysis software. The optomechanical analysis is carried out to ascertain radial and tilt alignment under assembly and on-orbit environmental condition.