During a recent visit with my folks, my mother was watching a series called NCIS, which apparently was playing "follow the leader" with all the CSI series. I don't know how good the series as a whole is, since I only have a sample of two episodes to go by, and boy was this one a stinker. Funnily enough, it falls into a subject I have taken classes for: Remote Sensing.
So, story involves a guy who worked at radiology at the local hospital, and has security clearance for the radioactive materials involved. He gets shot, and the investigation team finds this odd residue on him. They dig in, and meet up with a US intelligence officer who tells them it's a chemical marker they use to track terrorists by satellite.
Somehow, these spy satellites can even identify which individual is being tracked.
And tracking is "spotty" indoors.
And the satellites can track in real time on their monitors, which is how they track the guy (it turns out he wasn't a marked terrorist, just that a paranoid guy who designed the system was marking Americans he considered suspicious with a spray bottle.) when the terrorists who originally shot him steal his head to get past the retinal scanner to pick up the radioactive material.
Anyone who's paid the slightest bit of attention to middle school science should have some decent guesses with what's nonsense about this system.
1. The obvious one: Only geosynchronous satellites can "hover" over an area to monitor it, and outside of a certain zone, the view gets too tilted to be all that useful. Thus, you can't track something in real time by satellite unless you specifically put it in orbit in the general area ahead of time. That lack of mobility would severely limit the utility of a spy satellite.
2. How does the satellite sense the chemical? The chemical would need to generate or reflect some form of electromagnetic radiation. If it generated enough energy to be seen by satellite, it would eventually run out of chemical energy for doing so. And for a small spray of the stuff to be seen from orbit, it would need to generate a LOT of EMR. Additionally, it would have to emit this EMR at some frequency that stands out against all the background noise. Gamma/X-ray radiation? Would poison the terrorist and the people around him, and raise the chemical energy demands straight into nuclear reactions like radioactive decay. Ultraviolet? Would have trouble getting a clear signal out of the atmosphere, much less through the roof of a building. Visible light? Yeah, a glowing spot is going to be unnoticed. Near Infrared? How does the satellite tell the difference between that and plant life?
Middle infrared? Moisture. Far infrared? Would get lost in any heat source, not to mention it'd be a warm spot on the body. Microwaves or Radio waves? It would generate interference with other devices and be lost in the noise of those devices. You might as well start inventing Minovsky particles to explain it.
3. How does it tell one marked target from another, assuming you could get some magical signal? If it's just a chemical, I don't see how you could get it to emit a unique signature unless you tailor made each mixture for each target. Supposedly, you could get around that by telling the system "this spot is terrorist X, and this spot is terrorist Y." and it could track the spots as they change positions over time. But what if X and Y get close to each other? Then their "spots" would blend into one.
This nonsense goes off the deep end of "Big Brother" scenarios. They put a little token objection to the use of this sort of monitoring ability, but it comes across as half-hearted, even with the paranoid control freak, who decides to help them gain access to it to solve the case. This episode was just a wish fulfillment exercise, treating technology as if it were a magic tool that solves problems without any mental effort on the part of the humans. The computers do it all. The computers and satellites will catch the terrorists for us, and the only work we have to do is punch a few buttons instead of, you know, outsmart the people who avoid security for a living.
I'm glad my mother knew enough about science to be embarrassed by the show.