What is field of regard?

The field of regard (FOR) is a term used in the context of vision and optical systems, referring to the area or angle of visibility that is accessible to an observer or a system. It is the maximum angle or area that can be seen or monitored by a sensor or camera. The FOR can vary depending on the type and application of the system, the location and orientation of the observer or sensor, and the presence of obstructions or limitations in the environment. It is an important consideration in fields such as aviation, military operations, surveillance, robotics, and virtual reality, where the ability to detect, track, and respond to objects or events in the surrounding environment is critical. The FOR can be measured and analyzed using various methods, such as optical scanning, imaging, and simulation, to optimize the performance and effectiveness of the system.