Hybrid Velocity Data for the Velocity Measuring System of the Supersonic Naval Ordnance Research Track

A system is described for measuring the velocity of test sleds on the Supersonic Naval Ordnance Research Track (SNORT) with an rms error of less than 0.1 ft/second over a velocity range of 200 to 2000 ft/second and a bandwidth of 50 cps. Instrumentation consists of two data sources: sled-position vs time is measured with a magnetic-pickup track-coil system, and sled acceleration vs time is measured with a sled-borne accelerometer and PDM telemetry system. The tape-recorded data are converted to digital form and entered into the IBM-704 computer by automatic assessment equipment. The two different sets of data are combined by a near-optimum digital filtering technique to provide a set of hybrid wide-bandwidth data.