High-Tech Borders

The border patrol in the San Diego area is using GIS, GPS and biometrics to help curb illegal immigration.

by / May 6, 2001
Until recently, the U.S. Border Patrol, San Diego Sector, was an underfunded, understaffed operation with inadequate resources. But over the last five years, the federal government has transformed it into a well-equipped security operation with over 2,000 agents. Before the Clinton Administration initiated Operation Gatekeeper in 1994, apprehensions of illegal migrants in the area ran well over a half million annually. Since then, the numbers have dropped by 75 percent.

Operation Gatekeeper provided extensive funding and resources to restore integrity and safety to the San Diego Sector. In addition to major increases in personnel, resources andinfrastructure, the sector recently acquired geospatial and IT systems to assist in covert detection and speedy identification of smugglers and migrant traffic. These applications have already advanced the sectors intelligence and surveillance capabilities well beyond what they were in the mid-1990s.

At that time, the 66 miles from Imperial Beach, Calif., to the Anza Borrego Desert in the east -- officially designated the San Diego Sector -- was the most vulnerable portion of the U.S. southern international boundary, accounting for nearly one-fourth of all illegal border crossings throughout the Southwest. As illegal traffic climbed to tens of thousands annually, crime rates and property damage in border communities soared, and the quality of life in neighborhoods deteriorated.

But soon after Attorney General Janet Reno visited the area in 1993 and saw the situation first hand, funding and resources poured in. By the end of the decade, wire fencing through urban and beach areas of the border were replaced with a wall and lit with powerful lighting. Today, a fleet of helicopters with forward-looking infrared systems provides continual aerial coverage, and Zodiac boat teams patrol the river and ocean approaches. Special units with vans, bicycles and ATVs and on horseback cover the sector from the heavily populated urban coast to the remote eastern terrain.

Tracking with Technology

To further counter the movement of illegal traffic, San Diegos technical division began developing applications using GIS to integrate and analyze data from GPS, remote sensing, false infrared aerial imagery, night-vision scopes, seismic and infrared detectors and digitally scanned fingerprints.

One of the first applications was a GIS-based network of seismic and infrared sensors placed in strategic locations to expand surveillance and detection capabilities. Persons or vehicles passing over, through or nearby these devices trigger signals that are picked up and relayed by repeaters to the dispatch center and to each of the sectors nine stations. The time and the coordinates of the alerting sensor are displayed on a 3-D map of the area, enabling the dispatcher to estimate the migrants rate of travel.

Supervisory Border Patrol Agent John Block said the technical division is also entering the GPS survey coordinates of U.S. roads and migrant foot trails in the sector into ArcView. "Were looking at how the trail networks are changing and at how our operations are impacting movements along the border," Block said. "An increase in the number of trails helps us gauge the effectiveness of our operations. It also tells us if the traffic is moving elsewhere along the border or out of our area."

Vegetation stress analysis is also being field-tested. The sector is evaluating the ability of ERDAS Imagine software to analyze modified infrared aerial photography for chromatic differences between healthy vegetation and vegetation stressed by the passage of people and the waste they leave behind. Patrol Agent Daniel Isenberg explained that stressed vegetation shows up as a different color in the infrared spectrum than that of healthy vegetation. "The difference in color may tell us where migrants and smugglers are forming new routes, where they are laying up during the day and something about the amount of traffic along that path. From that we can change our response patterns accordingly."

Isenberg said the orthographically corrected, two-meter infrared imagery, procured through a partnership with the San Diego Association of Governments, will be flown quarterly and cover a strip one kilometer wide from the beach to the eastern edge of the sector. Vegetation stress and other indications from one quarter will be compared with imagery from the previous quarter.

In 2001, the division will also use ERDAS Imagine in conjunction with GIS and GPS to classify trail networks according to the estimated physical cost of crossing a particular terrain. Each type of soil, ground slope, vegetation, season, fence line and detection device in a given area is assigned a numerical level of difficulty then translated into a color-coded, scalable impedence factor for that terrain. The higher the factor, the greater the physical cost of getting through the area. The impedence factor for a given area is overlaid with migrant foot trails that have been GPS surveyed, and two are superimposed on a 2-D or 3-D basemap. "The composite lets us see exactly where the traffic is going, the high-impedence areas they are trying to avoid and their estimated rate of march," Isenberg said. "It also helps us determine where to put sensors and other resources in the area."

Biometric IDs

GIS query functions also have a key role in the sectors automated fingerprint identification (IDENT) system. Able to digitally scan fingerprints into a database in seconds, IDENT dramatically speeds the process of identifying repeat arrestees. According to Senior Patrol Agent Brandon Steele, individuals with a high number of repeat arrests for illegal crossings are often smugglers.

The first time someone is arrested, his or her fingerprints are digitally scanned into an Oracle database and assigned a number from the Fingerprint Identification Number System (FINS). The entry also contains the arrestees photograph and biographical data. "After that," Brandon said, "we identify the subject by FIN, not by name, because subjects often give false names."

With each arrest, agents do a GIS query of the database for FINs matching those of the arrestee. They can use the GIS to query more than 1.5 million sets of FINs, photos and bios for those matching the person being held, or look for recidivists with the most arrests for a particular month or year.

When a match is found, a unique symbol assigned to the FINs is displayed on the sector map. "We can click on a symbol and bring up a dialog window with the subjects number, photograph and biographical data. We can see when and where the subject was apprehended in the past, the area he is operating in and, often, with whom he is operating," Brandon said. "The first indication that somebody may be a smuggler is the number of hits that come up with a particular symbol. If two subjects apprehended in the same event have a lot of hits, its a good indication theyre working together for the same organization."

Looking Ahead

Block said it is too soon to assess the effectiveness of GIS and other technologies in helping detect and apprehend smugglers and illegal traffic. "Were bringing the stations online now with these new systems, so we really havent had enough time to quantify what they are accomplishing in terms of countering migrant traffic."

For now, however, there is little doubt that the integration of advanced technologies in border patrol operations will significantly enhance the agents ability to interdict and limit smuggling and illegal migration in the San Diego Sector.