Back at the command-and-control center a few hours later, I found myself on the other side of that camera, studying the same stretch of the river. The shift in perspective was dizzying. Twenty large screens lined the front wall of the control room and flickered from one surveillance camera to another; a television in the middle of the wall had been tuned to Fox News. Agents sat behind desks, scanning the monitors and occasionally speaking on the radio with agents in the field.
The Rio Grande Valley sector employs dozens of Remote Video Surveillance Systems, most of which are on fixed towers. Each RVSS is made up of four cameras, two of which are infrared for night duty. The agents who are assigned to camera duty in the control room zoom and pan the cameras as needed. At night they can manipulate the contrast of the infrared video, shifting from “black hot” to “white hot,” rewinding and forwarding through the digital file as needed to identify what is often merely a fleeting glimpse of an unidentified animal, possibly human. Sources of thermal energy abound. Rocks, concrete blocks and even the plants radiate heat, but warm-blooded animals stand out most vividly, and they move.
A seismic sensor buried alongside an active trail detects foot traffic and transmits its radio signal to the command center. Such unmanned ground sensors have been used for decades, but engineers continue to reduce their size and increase their sensitivity. Border Patrol agents have placed some 11,000 sensors along the U.S. border, and they move them constantly in an effort to keep up with the ever-shifting traffic patterns along the infinitely forking paths that radiate outward from the line.
Agent Jose Mancillas demonstrated what happens when he receives a signal from a ground sensor. He glanced left to a small screen displaying the current locations of his “bugs” and quickly typed a few keystrokes. One of three large flat-screen monitors at his desk instantly displayed a river camera’s infrared image. Using a joystick controller, he panned the camera and zoomed in. There wasn’t much to see just then, so he pulled up a file of a recent incursion. Eight ghostly white bodies sprang out of the brush and sprinted in an awkward hunkered-down posture toward the steel pickets of the border fence. They had activated the sensor about 50 yards south of the levee, three miles away from the Rio Grande. As soon as he had confirmed that there was traffic on the move, Mancillas had hit the radio, alerting a unit he knew was standing by just around the bend. We watched several members of the group perch on the fence; then the agents came into view and the aliens retreated. One leaped all the way from the top of the fence and hit the ground hard. We all winced. But he got up and ran south, back toward Mexico, with the rest of his group.
Suddenly all motion stopped. The file ran backward as Mancillas worked the controls of the NetGuard-EVS video client. He wanted to show me additional footage of recent traffic. Often you get just a flash of white, and it takes an experienced eye to determine whether to respond. The cameras are a good tool, but they can’t see everything, and the harsh South Texas weather degrades their performance. In January, during a severe cold snap, the cameras simply froze in place.
Upriver from brownsville lies McAllen, a more affluent community where local conditions, both natural (thick brush) and political (height restrictions), have prevented the deployment of remote video surveillance towers. Here the Border Patrol employs mobile surveillance systems that can be moved to hotspots as needed. Agent Jaime Medina joined us in McAllen and led an excursion into the broad fields that run alongside the levees that crisscross the fertile floodplain next to the Rio Grande.
Driving along a levee in the dark is a disconcerting experience. The land drops away sharply into an abyss of chirping crickets, singing frogs and other loud, gregarious creatures of the subtropical darkness. As I traveled with agents Milian and Medina through a night in which all fields were black, I had to strain my eyes to find some landmark. I tried to imagine what it was like patrolling out here with nothing but flashlights and a good sense of direction. We finally came to a “scope truck,” a pickup with a 20-foot retractable camera tower mounted on its bed. As with the stationary tower systems, the scope truck can shift between daylight and infrared viewing. We were parked on a kind of promontory or juncture in the levee. In daylight we no doubt would have been treated to a spectacular view of South Texas’s agricultural production. Historically, most of these vast fields have been worked by Mexican migrant workers, many of them undocumented.
Border Patrol officers monitor this area day and night, using scope trucks and also personal night-vision equipment such as the TAM-14, a short-range thermal monocular, and the Recon III Lite, a heavy thermal binocular, often mounted on a tripod, that includes a laser targeting system. The laser can guide agents wearing night-vision goggles to a group by fixing them with a beam invisible to the naked eye but brightly apparent to anyone wearing the proper eyewear. Such equipment, which was in short supply in previous years, is now widely used. After an impressive demonstration of the scope truck’s long-range thermal camera, the agents offered to show me the laser; wearing night-vision goggles, I was able to clearly see the red beam as it targeted a spot near the river.
Airplanes, helicopters and drones can highlight targets using similar devices to even greater effect. I later rode in a helicopter equipped with a FLIR Star Safire HD camera that was sensitive enough to detect the heat signature left by a body in high grass long after the body itself had moved on. The Star Safire comes equipped with a laser targeting system and a powerful infrared spotlight that can be slaved to the camera, and thereby bathe groups of aliens in a light they cannot see. As Mancillas had told me in the Brownsville control room, “it makes a huge difference when you can see in the dark.”single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.