Number Of Factors May Impede Situational Awareness
Situational awareness cannot be taken for granted, and anything that adversely impacts the performance of GPS signals and satellite navigation equipment needs to be watched closely.
In mid-April, the U.S. Air Force Research Lab Space Vehicles Directorate will launch the Communication/Navigation Outage Forecasting System (C/NOFS) satellite to demonstrate a technique for locating and forecasting scintillations in the ionosphere. Ionospheric scintillation is a phenomenon involving irregularities in plasma density and the impact that these irregularities have on the amplitude and phase of a radio signals including satellite signals. They occur in a belt extending out roughly 20 degrees latitude on either side of the equator and can be compared to a moderate to severe shockwave triggered by solar wind. This turbulence in the Earth’s ionosphere can disrupt, impede and even block L-band GPS signal transmissions as well as UHF satellite communications.
Today, scintillation sensors scattered around the world alert satellite operators one or two hours in advance of an event. A scintillation and tomography receiver payload carried into orbit in March 2007 aboard the Space Test Program Satellite-1 is helping to better our understanding of the impact of ionospheric scintillation and refraction on radio wave propagation.
C/NOFS is designed to take this understanding to yet another level as well as provide even more advanced warnings. Among its six payloads, C/NOFS will carry a GPS dual-frequency occultation receiver and an electromagnetic radio tomography beacon linked to ground receivers in order to measure multi-frequency scintillation, according to Laila Jeong, C/NFOS program manager at the Laboratory’s Space Vehicles Directorate’s Battlespace Environment Division. It is intended that these sensors will increase both the geographic coverage zone and warning time to three to six hours as well as provide 36-hour outlooks.
While these scintillations can create problems for satellite navigation users, some experts also are concerned that false and misleading displays on some satellite navigation receivers could be the result of human and not natural sources of interference.
A presentation by Andrea Barisani and Daniele Bianco at the CanSecWest Applied Security Conference held in Vancouver, April 2007 — “Unusual Car Navigation Tricks: Injecting RDS-TMC Traffic Information Signals” — created quite a stir.
Barisani, the chief security engineer at U.K.-based Inverse Path Ltd., and co-worker Bianco remotely hacked an in-car satellite navigation system, exposing a potential vulnerability in the radio data system–traffic message channel (RDS-TMC) standard.
Barisani and Bianco simply took control of the traffic message channel signal by injecting false information into the datastream and subverting “real” messages. In other words, without disrupting the flow of GPS data, they created a false sense of situational awareness.
Barisani and Bianco were able to manipulate the in-car display to show roads, bridges and tunnels as closed when they were open. They could create non-existent accidents and even display a phony plane crash site on-screen. Such a scenario would no doubt leave a victimized driver bewildered and searching for an appropriate alternative route.
This drew an immediate response from the TMC Forum, which backs the FM-based dynamic traffic information solution for in-car display systems used throughout Europe and North America and questioned the validity of Barisani and Bianco’s research in an attempt to negate it.
“We did it but not to shed a bad light on [the TMC Forum]. We just wanted to raise the issue,” says Barisani. “We are a security consulting company, and we [like to] demonstrate that security is a concern pretty much everywhere and not only on your desktop. We do not think hacking [the standard] is a real threat. This is simply a warning for the future.”
Barisani is urging vendors to evaluate and implement a suitable form of encryption.
So when it comes to your degree of situational awareness whether on the road or elsewhere, be aware that a lot is happening or might be happening behind the scenes.