SiC Scanning Mirror Assembly Design And Research

Aerial and astronautical camera play an increasingly important role in economicconstruction and national defense. In topographic mapping, resource survey, roadconstruction, water conservancy and agricultural planning, military reconnaissanceand many other fields, they have been widely used. The images gained from thecamera can provide the basis for urban planning and construction. In naturaldisasters they can help the command department to seize the opportunity to make adecision.Based on the research and development of a new camera, scanning mirrorwas placed before the entrance pupil in order to reduce the size and moment ofinertia. The camera needs to set two-dimensional scan. One was along the flightdirection and the other was perpendicularly to the flight direction. The scanningmirror and lens swings to achieve side-view imaging and expand ground coverage.When the camera is working, optical surface of the scanning mirror needs toensure high-quality (RMS130,λ=632.8nm). Meanwhile enough stiffness wasneeded. To meet these requirements, the form of composite triangle and quadrangle and the combination of open and semi-closed back was explored in the scanningmirror lightweight design. Combined with the structural features of the camera, theform of side face support was chosed. The environment changes when the camera isworking. In the support structure design of the scanning mirror, a flexible structurewas considered to compensate for the mismatch of the thermal characteristicsbetween the scanning mirror and support structure. It can also reduce stress passedfrom the assembly process. The change of optical surface was analyzed undergravity load and temperature load. The design result meets using demand.