The results of tests conducted with helmet-mounted sights (HMS) and helmet- mounted displays (HMD) are presented. To compare the accuracy of the different HMS systems (on a magnetic, acoustic, or optical basis) the authors find and unify a test procedure for verification. The test conditions vary, depending on the principle of the HMS system. Magnetic systems should be tested with the influence of magnetic disturbances, ultrasonic systems with the occurrence of noise and changing characteristics of the dispersion medium, and optical systems under high luminance to check saturation effects of the sensors. Modern integrated helmets (IH) consist of CRTs for displaying binocular images of TV--or infrared--cameras and superimposed symbology and a second channel with image intensifier tubes (IIT). Important points for checking CRTs are the resolution, distortion, homogeneity, and brightness in day and night. The most important test for the IIT channel is the resolution measured as a function of luminance of the test pattern. Tests of the basic helmet regarding head fit, earphone, center of gravity, weight, etc., are also necessary because these properties have an influence on the performance of the complete man-machine system.
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