Our dependency on GPS requires no further comment. That is fact. The six ways of crippling GPS are:
1.) Direct laser or rocket attacks against the GPS satellites. This is a ‘tough shot’ from the ground, and requires more money and technology than any of our currently perceived enemies possess. An attack like this is easier from space, but that still requires years of technological effort, of which no evidence has surfaced, and easily $100 million to execute. This is a low probability event.
2.) Nuclear or EMF radiating explosions near the GPS satellites might neutralize them with a planned near-miss. This is even more expensive and technically daunting, the ‘hardening’ of the GPS satellites means close proximity is required. The probability here is even lower.
3.) Launching a ton of gravel into the GPS satellites paths could shatter the solar panels within a few days. This might be done with a single rocket. The missile would be detected but its mission could only be guessed, until GPS goes dark. The budget for this, converting an eastern European rocket, probably runs below $20 million for a single shot, and $40 million for three launches to insure success. The probability of this occurrence in the next five years might be one in four. The dispersion of Al Queda, and their high fanatical, but lower technical orientation, suggests it’s out of reach for them. The next Chinese regime could easily accomplish this. The current North Korean regime might want to, but would need technical help. If Asian politics become more volatile, this has a 50:50 chance of occurring. It is a tiny budget item, even for a North Korea. Yet this causes so much upheaval, without direct confrontation, that the temptation to cripple GPS this way seems high.
4.) Guerilla attacks on GPS ground stations could impair the system. These stations, however, have been reinforced, but a ground assault by suicide squads could have effect. But since the terrestrial assets can be rebuilt in months this has no point unless coordinated with larger-scale military moves by an enemy. Suicide attacks rarely combine with coordinated military maneuvers, so the probability here is low.
5.) Spoofing GPS may be the most lethal of any approach. Since GPS signals are weak, and passive or non-interactive, over-riding the transmissions is easy. This sends ships into shoals, missiles into hospitals and troops away from battle lines. A backup system, however, would detect this and reverse the surprise for an enemy. Many in the military are concerned about spoofing. Blanking out and replacing the GPS transmissions is easy, but substituting credible counterfeit signals is challenging. This suggests only a technically advanced opponent could attempt spoofing, and it would need to be part of a larger military conquest. The probability, therefore, is lower for this approach, but the consequences could be disasterous.
6.) Jamming GPS across battlefields with a hundred mile radius is simple. The Russians market a jammer for $5000 that does this, and fits in a coat pocket. Deploying twenty could bring down a continent. The probability of malicious use is quite high, although should always be detectable.
Related:
- Intro to GPS Apps GPS Policy Studies
- HOW GOOD IS GPS?: The Civilian – Military Relationship and the Impact on GPS Performance