Software-only IR image generation and reticle simulation for the HWIL testing of a single detector frequency modulated reticle seeker

Hardware-in-the-Loop (HWIL) testing of seeker systems usually requires a 5-axis flight motion simulator (FMS) coupled to expensive hardware for infrared (IR) scene generation and projection. Similar tests can be conducted by using a 3-axis flight motion simulator, bypassing the seeker optics and injecting a synthetically calculated detector signal directly into the seeker. The constantly increasing speed and memory bandwidth of high-end personal computers make them attractive software rendering platforms. A software OpenGL pipeline provides flexibility in terms of access to the rendered output, colour channel dynamic range and lighting equations. This paper describes how a system was constructed using personal computer hardware to perform closed tracking loop HWIL testing of a single detector frequency modulated reticle seeker. The main parts of the system that are described include: * The software-only implementation of OpenGL used to render the IR image with floating point accuracy directly to system memory. * The software used to inject the detector signal and extract the seeker look position. * The architecture used to control the flight motion simulator.