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:
“... it is not the color of the skin that makes the man or the woman, but the principle formed in the soul. Brilliant wit will shine, come from whence it will; and genius and talent will not hide the brightness of its lustre.”
—Maria Stewart (1803–1879)
“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)