Calif. ranchers wield British radar to detect illegal border crossers.

• Author: Jean, Grace V.

LONDON -- Frustrated by trespassers attempting to cross into the United States illegally, ranch owners in southern California have purchased a British radar in an effort to protect their property and to help Border Patrol agents nab more intruders.

The Blighter B202 Radar, developed by Plextek Ltd., an electronics and communications design consultancy based near Cambridge, U.K., detects people walking or crawling through the rocky, hilly landscape from four kilometers away, says Nicholas Booth, manager of Blighter sales and marketing.

The man-portable, scanning radar is mounted on a tripod and runs on rechargeable lithium ion batteries. It has a 20-degree wide vertical elevation beam that permits the detection of targets in the distance as well as up close.

"You can see people walking up and down the mountain and on the plains at the same time," says Booth.

Traditional radars would require tilting to cover the same area.

When the Blighter radar detects movement, the target is displayed on a map with information on its exact location, size and speed. Other elements of the ranchers' surveillance system, including day/night cameras, acoustic and warning devices and unattended ground sensors, help to confirm whether the target is human. But the devices are subject to environmental factors that may hinder their effectiveness.

"We regularly experience early morning coastal fog that renders our [infrared] cameras useless," one of the ranch owners says in a company press release. "Of all the surveillance...