GB1329838A - Detecting arrangement for indication of hits - Google Patents

Abstract

1329838 Teaching surface AAI CORP 23 Dec 1970 [29 Dec 1969] 61045/70 Heading F3C A detecting arrangement, for indication of hits, comprises a detector for a target signal, and an analog simulating digital filter signal transmission attenuating unit disposed in signal path intercepting relation to said detector, the attenuating unit having a digital filter signal transmission ratio which varies as a general function of transverse distance from a given selected zero position at the filter. The detector is a photoscope 11, Fig. 1, which detects the ability of an operator to aim at a target T, for example, a tank having a detectable signal generator such as a light beacon L. The photoscope 11 has an objective lens 21 which collects light from the light beacon L, a field mask 31, a filter mask 41, a field lens 51 and a photodiode 61, the light being masked by the field mask 31, filtered by the filter mask 41 and then passed from the photodiode 61 to an indicator 91, via a threshold trigger 71 and an amplifier 81. The field mask 31 has a triangular aperture 33 aligned with a digital-analog filter section 43, 45, Figs. 1 and 4, of the filter mask 41. In use the photoscope is aimed at targets which are a range of distances therefrom and, as the light beacon L is of constant intensity, the light received by the photoscope will vary inversely to the square of the distance of the target 7 from the photoscope. The primary variation of amplitude of the light signal reaching the photoscope 11 from the target 7 and its light beacon L is caused by the inverse square variation as a function of range of the target and this variation is conveyed to the indicator 91.