Principle of Guidance (semi-active Version)
The launching aircraft will illuminate the target with its radar. In radars of the 1950s these were single target tracking devices using a nutating horn as part of the antenna. This caused the beam to be swept in a small cone. Signal processing would be applied to determine the direction of maximum illumination and so develop a signal to steer the antenna toward the target. The missile detects the reflected signal from the target with a high gain antenna in a similar fashion and steers the entire missile toward closure with the target. The missile guidance also samples a portion of the illuminating signal via rearward pointing waveguides. The comparison of these two signals enabled logic circuits to determine the true target reflection signal, even if the target were to eject radar-reflecting chaff.
Read more about this topic: AIM-7 Sparrow
Famous quotes containing the words principle and/or guidance:
“We have been here over forty years, a longer period than the children of Israel wandered through the wilderness, coming to this Capitol pleading for this recognition of the principle that the Government derives its just powers from the consent of the governed. Mr. Chairman, we ask that you report our resolution favorably if you can but unfavorably if you must; that you report one way or the other, so that the Senate may have the chance to consider it.”
—Anna Howard Shaw (1847–1919)
“Even healthy families need outside sources of moral guidance to keep those tensions from imploding—and this means, among other things, a public philosophy of gender equality and concern for child welfare. When instead the larger culture aggrandizes wife beaters, degrades women or nods approvingly at child slappers, the family gets a little more dangerous for everyone, and so, inevitably, does the larger world.”
—Barbara Ehrenreich (20th century)