Procedure for Surveying a Station in the U.S. Army Research Laboratory Transonic Experimental Facility Spark Shadowgraph Range

Abstract : The indoor instrumented spark range at the U.S. Army Research Laboratory Transonic Experimental Facility was designed for firing various-caliber projectiles to establish their free-flight characteristics. The in-flight position and orientation of the projectile is measured using 25 orthogonal pairs of spark photography stations, providing a set of shadowgraphs. An intrinsic part of the spark range instrumentation is the complex fiducial system that resides within the facility. This report presents the step-by-step method used to survey one of the 25 orthogonal fiducial stations using specialized equipment and techniques. Such a survey may be conducted to measure and record the position of an existing fiducial bead, reattach a bead to an existing fiducial wire, or be part of a larger effort to replace a broken or damaged fiducial wire or other system component.