Since conical scanning systems depend on the signal growing or weakening due only to the position of the target relative to the beam, such changes in reflected signal can cause it to be " confused " about the position of the target within the beam's scanning area.
22.
Although conical scanning allowed accurate measurement of the angle of the target, it did not directly indicate which direction to turn the antenna to center it this could be seen in the rising and falling blip strength, but in practice this was far too fast to follow visually.
23.
To achieve high accuracy and measure both azimuth and elevation with one antenna, it used a conical scanning system, in which the beam is rotated around the antenna's axis to find the maximum signal point, thus indicating which direction the antenna should move in order to point directly at the target.
24.
The " W�rzburg D " was introduced in 1941 and added a conical scanning system, using an offset receiver feed called a " Quirl " ( German for whisk ) that spun at The resulting signal was slightly offset from the centreline of the dish, rotating around the axis and overlapping it in the centre.
25.
Whilst use of the lobe alone might allow an operator to " hunt " for the strongest return and thus aim the antenna within a degree or so in that " maximum return " area at the center of the lobe, with conical scanning much smaller movements can be detected, and accuracies under 0.1 degree are possible.
