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How can one find LOCATION of such active jammer? EDIT: How can one find location of a jammer? I'm interested in the process and equipment needed to find locati

How can one find LOCATION of such active jammer? EDIT: How can one find location of a jammer? I'm interested in the process and equipment needed to find location of active jamming device in a geographic area. E.g. what police uses and how can an average person like me do the same.

astura 5y ago
Alibaba or any other sketchy importer.
wizzwizz4 5y ago
Your phone can detect the network signal strength. Flip the algorithm on its head: detect the network noise strength – how much radio noise is drowning out any signal. Then just keep walking in the direction of higher bars, and you'll find the jamming device.
GrumpyYoungMan 5y ago
See https://en.wikipedia.org/wiki/Direction_finding https://en.wikipedia.org/wiki/Direction_finding If you wanted to do it cheaply and crudely, you at least need a portable spectrum analyzer that covers the frequency range you're investigating and a rubber ducky antenna that covers the frequency range you're investigating and then drive around watching for where the signal strength increases. (Make sure the antenna is outside the car since the metal of the body will interfere with reception of signals.) Professional spectrum analyzers used for engineering are quite expensive (I'm told that Rigol's SAs are good for the price) but you might be able to get away with less expensive instruments like the RF Explorer or even an RTL-SDR and one of the software spectrum analyzer packages out there, assuming they cover the frequency range you're interested in. By definition, jamming needs to be powerful enough to drown out any competing signals so it should be obvious if jamming is occurring even to relatively low sensitivity instruments.
mindcrime 5y ago
Roughly speaking, you just need a mobile receiving unit, or multiple fixed receiving units, with a reorientable directional antenna. You find the heading where the signal has maximum strength from a few points, and then triangulate. There are relatively inexpensive Software Defined Radio devices to enable this sort of thing. See: https://www.crowdsupply.com/krakenrf/krakensdr https://www.crowdsupply.com/krakenrf/krakensdr https://www.rtl-sdr.com/ksdr/ https://www.rtl-sdr.com/ksdr/ Other related discussions here on HN: https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=27857290 https://news.ycombinator.com/item?id=27857290

astura 5y ago

Alibaba or any other sketchy importer.

wizzwizz4 5y ago

Your phone can detect the network signal strength. Flip the algorithm on its head: detect the network noise strength – how much radio noise is drowning out any signal. Then just keep walking in the direction of higher bars, and you'll find the jamming device.

GrumpyYoungMan 5y ago

See https://en.wikipedia.org/wiki/Direction_finding https://en.wikipedia.org/wiki/Direction_finding If you wanted to do it cheaply and crudely, you at least need a portable spectrum analyzer that covers the frequency range you're investigating and a rubber ducky antenna that covers the frequency range you're investigating and then drive around watching for where the signal strength increases. (Make sure the antenna is outside the car since the metal of the body will interfere with reception of signals.) Professional spectrum analyzers used for engineering are quite expensive (I'm told that Rigol's SAs are good for the price) but you might be able to get away with less expensive instruments like the RF Explorer or even an RTL-SDR and one of the software spectrum analyzer packages out there, assuming they cover the frequency range you're interested in. By definition, jamming needs to be powerful enough to drown out any competing signals so it should be obvious if jamming is occurring even to relatively low sensitivity instruments.

mindcrime 5y ago

Roughly speaking, you just need a mobile receiving unit, or multiple fixed receiving units, with a reorientable directional antenna. You find the heading where the signal has maximum strength from a few points, and then triangulate. There are relatively inexpensive Software Defined Radio devices to enable this sort of thing. See: https://www.crowdsupply.com/krakenrf/krakensdr https://www.crowdsupply.com/krakenrf/krakensdr https://www.rtl-sdr.com/ksdr/ https://www.rtl-sdr.com/ksdr/ Other related discussions here on HN: https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=27857290 https://news.ycombinator.com/item?id=27857290