Artillery observer

A military artillery observer, spotter or FO (forward observer) is responsible for directing artillery and mortar fire onto a target and may be a Forward Air Controller (FAC) for close air support and spotter for naval gunfire support. Also known as Fire Support Specialist or FISTer, an artillery observer usually accompanies a tank or infantry manoeuvre unit. Spotters ensure that indirect fire hits targets which the troops at the fire support base cannot see.