An instrumentation system has been developed which rapidly measures and records the elevation of the runway. The profile data are recorded in a form which can be used directly by existent data processing facilities at WADD.nThe system consists of two parts, the collimator which projects a highly collimated light beam down the runway, and a profilometer equipped with a photoelectric sensor. As the profilometer is towed down the runway, the sensor is held centered on the light beam by a servo system. A simple direct drive introduces the profile variations between the surface and the sensor position into a shaft-position-to-digital encoder. The output of the encoder is punched on paper tape.nAccuracy and repeatability tests have shown that the profile instrumentation system is capable of accuracies which are well within run-way data requirements.
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