So, this question is inspired by the wire-guided FPV drones used in Ukraine. In Ukraine, to overcome jamming, missile wire spools are mounted to the drone so that just like you can have a wire-guided missile, you can use this same wire to connect video and controls to the drone, so that you can fly your FPV drone into a jamming-rich environment and as an added bonus you do not create any video transmission to be intercepted, which can be used to detect drones. So even if there is no jamming, the wire-spools can be used to keep your flight a secret until the drone is very close.

But, I happen to be aware that there are instruments on spacecraft that are used to measure the magnetic fields of planets surfaces, or am I correct about this? So, It is possible to analyze the various dynamics of the magnetic fields of mars from space correct?

Could similar instrumentation be used to detect drones in flight, which power large motors creating magnetic fields?

 

In theory, yes. In practice, probably not at a useful distance, particularly in comparison to other detection methods, such as acoustic detection of the prop noise.

Keep in mind that any battlefield is a very chaotic and noisy RF/EM environment. In a sufficiently quite environment, you might be able to detect the switching transients related to the motor at a distance of a few hundred meters (guessing), but other RF sources, such as the local oscillator in the GPS receiver, might be easier. Also keep in mind that the operators of the drone are going to be taking measures, such as shielding, so make this harder (should it prove to be an exploitable vulnerability).

 

In theory, yes. In practice, probably not at a useful distance, particularly in comparison to other detection methods, such as acoustic detection of the prop noise.

Keep in mind that any battlefield is a very chaotic and noisy RF/EM environment. In a sufficiently quite environment, you might be able to detect the switching transients related to the motor at a distance of a few hundred meters (guessing), but other RF sources, such as the local oscillator in the GPS receiver, might be easier. Also keep in mind that the operators of the drone are going to be taking measures, such as shielding, so make this harder (should it prove to be an exploitable vulnerability).

I just have some remarks, for the sake of entertainment.

shielding motors is not a lightweight thing to do, and motors need to be as light as possible, because drones really need every gram. There's absolutely no way they're doing this right now, the motors will be engineered for performance and only performance. Also, the entire function of a motor is to be as powerful of an electromagnet as it can be, so containing the magnetic field would not be simple. It would have to house the entire motor and be heavy. A piece of tape is heavy with drones.

The battlefield is chaotic, but also presently it is huge. not everywhere is a constant target.

basically we would be talking about a compass that works like a seismograph. So I guess it would be like, some places are too noisy, but some places I would be imagining that the "magnetograph" would be able to spike to signal that a motor was in use?

 

wire-guided FPV drones

The 'wire' is actually an optical fibre, which has the advantage that there is no externally-detectable EM field.