Technical description

Because the performance of CanariCam depends on the quality of the entrance window, a window-imaging mode shall be implemented to permit monitoring of the outer surface of the window. One should be able to inspect the window surface for the presence of dust or other contaminants that can block and/or scatter light and emit infrared radiation that contributes to the thermal background. This mode is set up by inserting a special double-lens assembly near the telescope focal plane.