Hi
I am hoping to find an SDR that could not only detect IMSI but also providing signal strength information to figure out directions. I would really appreciate any advice on this.
We’re trying to capture cellphones on 3G and 4G/LTE networks and then perform radio location finding for each detected device.
I’m looking to perform a direction finding of a given smartphone with at least some degree of accuracy. Small places ~10m radius.
Has this been tested by Othernet for phones?
Thanks,
Dil
it would be easier with the shorter 900mhz+ freqs but back in the day we needed to have the 121.5 tuned antennas at the tips of wing on SAR aircraft to get a good DF on a crashed plane’s ELT.
If I recall correctly the circuit inverts one signal combines and cancels out the weaker pushing the needle left or right; then take a heading when you get a zero and get that several times on a map grid to triangulate your signal.
No reason you cant do that in software vs analog clash of antenna rx; probably need one SDR pulling GPS for accurate timing.
This tech kinda sucks though from a privacy standpoint, though something similar is already nearly universally long in place by cell companies and shared with the state, but private snooping is not great either.
I would refer you to the blog post of finding intermittent signals since the phone is not continuously transmitting
https://www.rtl-sdr.com/forum/viewtopic.php?f=9&t=4602