/sci/ - Science & Math

>>10421216
>>a katana will show up on radar.
hell fucking yes.
>> using this in warzone
Pic related. It's not a warzone, but I think detecting an elephant poachers rifle from an airplane certainly counts
It would be more surprising if a katana was for whatever reason undetectable on radar. In general, something is going to interact with radar waves when it's conductive and has a dimension at least more than one wavelength longer than that of the radar wavelength. A katana's like 60 cm long, that's like 5 wavelengths of 2.4 GHz. 2.4 GHz is about the frequency which wifi operates at, there are certainly radars that operate high than this. So a lot of things interact with radar waves, but what we can exploit here is that a katana will interact with radar waves in a particular manner. Because of this unique signature we can pick it out from the noise. You can detect quadcopters just from the fact that their spinning rotors have a distinct radio signature. Even though said rotors are made of plastic they still interact with radar enough that they can be detected:
https://www.semanticscholar.org/paper/Classification-of-small-UAVs-and-birds-by-Molchanov-Egiazarian/b9ff35d06b3b7a5664461a3257181473d5ec0dbb
You can even detect human through 9 meters of rubble just because a human breathing has a distinct radio signature:
https://www.dhs.gov/detecting-heartbeats-rubble-dhs-and-nasa-team-save-victims-disasters
For short range detection you can actually buy a radar capable of detecting katanas:
https://patriot1tech.com/solutions/patscan-cmr/
The technology to do this over longer ranges reliably and without human intervention is being investigated, although it is somewhat new. It might receive more funding though as it might be a way to prevent mass shootings:
https://news.umich.edu/after-newtown-a-new-use-for-a-weapons-detecting-radar/