Steering
If there is an "S" in the antenna's designation, then it is steerable. This might be achieved electronically by adjustment of the phases of the signals fed to the columns of dipoles, or physically by mounting the entire array on a gigantic rotator. An example of this can be seen at NRK Kvitsøy, where a short circular railway carries a pair of wheeled platforms at opposite ends of a diameter-arm. Each platform has one of the support towers for the curtain array standing on it, the curtain is slung between the towers.
Another physical rotation technique is employed by the ALLISS system where the entire array is built around a central rotatable tower of massive strength.
Electrically steered arrays can usually be steered about ±30° from the antenna's physical orientation. Physically rotated arrays can obviously manage the full 360°. Electrical steering is typically done in the horizontal plane, with some adjustments being possible in the vertical plane.
Read more about this topic: HRS Antenna
Famous quotes containing the word steering:
“Behind the steering wheel
The boy took out his own forehead.
His girlfriend’s head was a green bag
Of narcissus stems. “OK you win
But meet me anyway at Cohen’s Drug Store
In 22 minutes.””
—John Ashbery (b. 1927)
“In our most trivial walks, we are constantly, though unconsciously, steering like pilots by certain well-known beacons and headlands, and if we go beyond our usual course we still carry in our minds the bearing of some neighboring cape; and not till we are completely lost, or turned round,—for a man needs only to be turned round once with his eyes shut in this world to be lost,—do we appreciate the vastness and strangeness of nature.”
—Henry David Thoreau (1817–1862)
“The boat is made of dry reeds, and a monkey is steering it.”
—Punjabi proverb, trans. by Gurinder Singh Mann.