‘Virtual radar’ system raises security concerns

 - September 19, 2006, 8:19 AM

The popular but, some would say, odd pastime of planespotting has recruited new high-tech help, a “virtual radar” hooked to a personal computer that allows spotters to decode transponder signals and track aircraft in real time.

Developed by Kinetic Avionic Products of London, the SBS-1 Real-Time Virtual Radar is also useful for ATC training, monitoring compliance with airspace and noise-restricted areas, flight-school fleet tracking, analysis of traffic pattern operations and for small airports to have ATC-like functionality at a much lower cost.

The SBS-1 receives mode-S and ADS-B signals and displays available aircraft information on a radar-like display on a computer screen. The system consists of a receiver box that weighs about a pound and connects to a computer via a USB cable, a magnetic-mount antenna and Kinetic’s Basestation software.

The system is portable, according to Kinetic, and can be powered through the USB cable when away from an electrical outlet. Range is as much as 250 miles, depending on antenna location, and the only limit to the number of targets that can be tracked is the size of the user’s hard drive.

As mode-S and ADS-B become more prevalent, the ease with which anyone can capture these signals raises the question of whether products such as the Kinetic SBS-1 pose security risks. This is, of course, similar to an issue security authorities raised in the wake of 9/11 and that resulted in sporadic restrictions against planespotter activity near airports.

Data on aircraft movements is easy to obtain through the Aircraft Situation Display to Industry (ASDI) system flight trackers use. Operators can choose to keep their registration numbers private by using the blocked aircraft registration request (BARR) process available at NBAA (see www.nbaa. org/asdi). But BARR can’t block ADS-B or mode-S information because those signals are transmitted from the aircraft and then captured by a receiver on the ground. BARR relies on data that is first detected by a radar system and then disseminated by computers.

Judging from some chatter on Kinetic’s Web site forum, spotters are using their SBS-1 systems to watch some possibly unknowing operators. On February 24, for example, one forum member wrote, “I spotted an ADS-B-equipped Gulfstream yesterday.” Last October, a spotter had this to say: “Had one today N1090X, Hex A02891 CL604, my very first track-in to near-by R.A.F Northolt, could possibly have been U.S. gov’t, though some civvy traffic goes in there.” Another spotter Googled the registration and explained that this Challenger belonged to Xerox.

“We block our tail numbers,” Xerox chief pilot John Mastrocinque told AIN. “We’re concerned about this, like all the Internet [tracking] programs, but there’s not much I see we can do about this.” He suggested there ought to be a way to encrypt the identification information.

One spotter’s use of the SBS-1 suggests a feature that could be helpful during an emergency. This spotter asked, “Did anyone catch the Kalitta AL B742 (N713CK) squawking 7700E this morning?” Presumably, if hijacked aircraft had mode-S or ADS-B that couldn’t be shut off by hijackers, more eyes looking at targets might help alert authorities earlier.

ASDI information is much more comprehensive than what a single SBS-1 can provide because ASDI includes flight-plan information, and tracking companies can use this to show where the aircraft originated and its destination. SBS-1 users have the option of networking their systems to create wide-area tracking capability, so even though flight-planning information is not available via mode-S, Virtual Radar users could figure out where an aircraft ends up.

For now, not many business aircraft are equipped so that they can be detected by systems such as the SBS-1. “I haven’t heard about this technology,” said Steve Brown, NBAA senior vice president for operations, “but from looking at what little information is available, it appears able to detect only ADS-B and mode-S aircraft, which are a minority of those in the system.”

In the U.S., mode-S exemptions end for Part 121 and 135 operators after March 1 next year (when mode-C transponders can no longer be repaired). And if proposals to make airspace use more efficient pan out, it is likely that mode-S and ADS-B will become ubiquitous, in which case products such as the SBS-1 Virtual Radar might come under closer scrutiny.