An invisible fence is an electronically generated 3-dimensional boundary that may take any geometrical shape to enclose an area, as well as surround individual animals, but is unseen by the eye. Invisible fences control animals that are wearing radio frequency (RF) receiving devices capable of capturing electronic signals. The majority of signals used in invisible fences are between 3,000 hertz and 300 gigahertz. Invisible fences use sensory cues to invoke a change in an animal’s behavior or movement. Large animals can be controlled using audio cues, such as whistles, beeps, the human voice or any combination of them. Electric shock is also a cue used to control animal movement. Most commercial invisible fencing devices contain RF receivers that contain safety features aimed at preventing inhumane cuing, thus promoting an optimal animal experience. High frequency RF signals are emitted from a ground-based transmitter; however many invisible fencing systems will require many transmitters when the containment terrain is rugged and uneven.
Read more about Invisible Fence: History, GPS-Fencing, Disadvantages, Innovations in Cattle Herding
Famous quotes containing the words invisible and/or fence:
“the quicksilver art
Throws back the invisible but lightning mass
To inhabit the room; for I have seen it part
The palpable air....”
—Allen Tate (18991979)
“Processions that lack high stilts have nothing that catches the eye.
What if my great-granddad had a pair that were twenty foot high,
And mine were but fifteen foot, no modern stalks upon higher,
Some rogue of the world stole them to patch up a fence or a fire.”
—William Butler Yeats (18651939)