Measuring projectile velocity (1987)
After the establishment of TNO-FEL in 1984, the Army Material Testing Department 1 (MBA1) commissioned a project to TNO to investigate whether it is possible to measure the speeds of large-calibre projectiles at very high passing heights using optical detection, for example, to take an image of a 105 mm projectile at 70 metres height. For the research, a two-meter photo beam was built with two optical detectors (according to the proven principles) which have the best possible signal-to-noise ratio. Signal processing is applied to the detected signals so that a reliable signal-to-noise ratio can be reliably detected. This project was named “Measurement Equipment Speed Projectile” (MUSP).
The signals from the optical detectors are stored in computer memory as a function of time. These signals represent the shadow profiles of the projectiles that passed. By measuring the time interval between the signals, the flight time over the measuring base of the photo bar is known. Given the known distance between the two detectors, the flight speed can be calculated. Correlation technology was used to determine this flight time. This method can be used very well in case of poor signal/noise or interference ratios, which makes it possible to measure under more difficult conditions.