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:
“The sons of Judah have to choose that God may again choose them.... The divine principle of our race is action, choice, resolved memory.”
—George Eliot [Mary Ann (or Marian)
“Now narrow minds can develop as well through persecution as through benevolence; they can assure themselves of their power by tyrannizing cruelly or beneficently over others; they go the way their nature guides them. Add to this the guidance of interest, and you will have the key to most social riddles.”
—Honoré De Balzac (1799–1850)