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    "localId": "486498244",
    "label": "Report, OSI - 10-50, Central Intelligence Agency, Soviet Guidance and Control Development Particularly as Applied to Guided Missiles",
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    "contentType": "document",
    "title": "Report, OSI - 10-50, Central Intelligence Agency, Soviet Guidance and Control Development Particularly as Applied to Guided Missiles",
    "citationUrl": "https://catalog.archives.gov/id/486498244",
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        "President's Secretary's Files (Truman Administration)",
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    "productionDates": [
        {
            "day": 6,
            "logicalDate": "1950-04-06",
            "month": 4,
            "year": 1950
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{
    "seq": 33,
    "pageIndex": 0,
    "type": "photo",
    "url": "https://s3.us-east-1.amazonaws.com/NARAprodstorage/lz/presidential-libraries/truman/hst-psf/602196/875492/875492-02-033.tif",
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    "ocrText": "TOP SECRET\n\"The\npulse control systems though vulnerable to jamming,\nappear to be a considerable improvement in this respect over\nthe Strassburg-Kehl.\"\nC. Homing Systems\nIn addition to the several command guidance systems mentioned above, consider-\nable effort was expended by the Germans on the development and production of auto-\nmatic target-seeking devices and homing heads. The over-all problem of automatic\ntarget-seeking devices intended to bring the target within the field of view of a homing\nhead was known as Krucke.\nThe Krucke problem was a very difficult one to solve, and\nit should be emphasized that at the end of the war the associated equipment was in a very\nrudimentary stage.\nMost scientists in Germany thought it impractical to attach the homing head\nrigidly to the missile. Their reason was that, upon giving a command to correct an\nobserved error, the angle of attack (direction of the missile axis in reference to the\ndirection of the trajectory) changes and so the observed error is cancelled or perhaps\neven reversed in direction without appreciably changing the course.\nA possible solution was to affix the axis of the homing head to the direction of the\ntrajectory itself and not to the longitudinal axis of the missile. This could be accom-\nplished by having the axis of the homing head always point in the direction of the wind-\nstream by means of a device similar to a weathervane. When a target-covering, or\nline-of-sight, course was used to bring the missile to the vicinity of the target it was\nnecessary to recognize that the direction of the trajectory was different from the\ndirection of the line of sight from control operator to target. For speed ratios of\nmissile to target of two-to-one this angle might be as much as + 30 degrees. If the\naxis of the homing head was affixed to the direction of the trajectory, the field of view re-\nquired would be greater than + 30 degrees, and for automatic target-seeking devices this\nrepresented an all but impossible situation.\nThe maximum operating range of any homing device, whether optical, infrared,\nradio, or acoustical, is closely related to its field of view or beam width. As a first\napproximation the total energy received is proportional to the solid angle of the beam\nand also inversely proportional to the square of the range. For all homing devices under\ndevelopment at the time the angle of view was restricted to the order of + 6 degrees\nwith a usable range of several kilometers.\nIf this had not been true the homing device could have been set on the target prior\nto launching and no krucke problem would have existed, and furthermore, no other\nguiding scheme, such as remote control by the target-covering method, would have been\nrequired.\nAnother reason for restricting the field of view was the matter of target\ndiscrimination. Were several targets to appear simultaneously within the field of view,\nthe target-seeking device would become confused and seek the average path.\nThe method by which the homing head should direct the missile had also to be\nconsidered. The pursuit course, which is a type of homing course, was perhaps the\nsimplest and required the least amount of equipment within the missile. But it had a\nmajor disadvantage in that the missile would at all times be directed toward the target.\nThis procedure, as was well known, leads to a missile course of ever increasing\ncurvature (for straight-line constant-velocity motion of the target) and results in an\ninfinitely small radius of curvature for speed ratios of missile to target greater than\ntwo-to-one. A constant-bearing collision course was undoubtedly the best from the\nviewpoint of missile capabilities but was more complicated from the point of view of\nthe homing device and required more equipment.\nHUMA\nNARA\nTOP SECRET\n24"
}