Electro-optical systems are used in a variety of applications such as imaging, targeting, ranging, tracking, surveillance, and reconnaissance, among other military and civilian applications. In many such systems, multiple imaging sensors sharing a common image plane each produce respective images of a target or scene. In certain multi-spectral, electro-optical systems, different imaging sensors within the system are receptive to different spectral bands of electromagnetic radiation or light. These different spectral images allow an operator to detect and identify target characteristics that may otherwise be concealed when viewing the target in a single, narrower spectral band. Mutual alignment of the various imaging sensors within the system is necessary for ensuring that the field of view (FOV) of each respective sensor is aligned.
Typically, misalignments in an electro-optical system are detected and cured with the use of targeting boards during an initial alignment process at the time of manufacture. Since alignment tends to drift over time, targeting boards are periodically used to realign the imaging sensors. In such systems, a targeting board is located at a distance from the electro-optical system and illuminated so that it is clearly visible to all sensors. By aligning the sensors with the common targeting board, misalignments in the optical system may be detected and properly addressed.