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North Korean ICBM launch detected using GPS

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Re: North Korean ICBM launch detected using GPS

#2
>Missiles make ionospheric disturbances that GPS records. The yellow ripple is the ionospheric disturbance.

Where can I read more about the meta level concept of "isopheric disturbances"? (Because I suspect I'll find this has been done by military intelligence for a long time then rediscovered by so called "arms control" wonks who insist on putting their code into the public domain.)

Re: North Korean ICBM launch detected using GPS

#3

>Missiles make ionospheric disturbances that GPS records. The yellow ripple is the ionospheric disturbance. Where can I read more about the meta level concept of "isopheric disturbances"? (Because I suspect I'll find this has been done by military intelligence for a long time then rediscovered by so called "arms control" wonks who insist on putting their code into the public domain.)

The second tweet in the linked thread links to the paper which inspired them:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

> who insist on putting their code into the public domain

You say that as if there is something wrong with that.

Re: North Korean ICBM launch detected using GPS

#4

>Missiles make ionospheric disturbances that GPS records. The yellow ripple is the ionospheric disturbance. Where can I read more about the meta level concept of "isopheric disturbances"? (Because I suspect I'll find this has been done by military intelligence for a long time then rediscovered by so called "arms control" wonks who insist on putting their code into the public domain.)

If you follow the thread, there’s a link to https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201... which contains this introduction:

======== It is widely recognized that rocket launches can be an anthropogenic source to trigger traveling ionospheric disturbances (TIDs) by generating acoustic-gravity waves (Afraimovich et al., 2002; Arendt, 1971; Bowling et al., 2013; Calais & Minster, 1996; Chou et al., 2018; Ding et al., 2014; Kakinami et al., 2013; Li et al., 1994; Lin et al., 2014; Lin, Chen, et al., 2017; Lin, Shen, et al., 2017; Noble, 1990). The rocket-induced long-distance propagating TIDs associated with shock/ducted gravity waves and internal gravity waves were observed by using Arecibo incoherent scatter radar (Noble, 1990) and ground-based Global Positioning System total electron content (TEC) observations (Calais & Minster, 1996). Lin, Shen, et al. (2017) first reported the rocket-induced shock waves and concentric TIDs (CTIDs) subsequently using Global Positioning System TEC over California-Pacific region. They suggested that the CTIDs are the manifestation of concentric gravity waves that were originated from the mesopause region. ====

The effect seems to be proven quite a while ago. Using GPS receivers to make that widely accessible seems to be new, but I honestly doubt that military intelligence would rely on that - I’m confident they have more direct methods to detect launches such as (radar) satellites.

Re: North Korean ICBM launch detected using GPS

#8
post #6

I'd like to see the amount of false positives/negatives, rather than just data of one day.

They don’t really seem to have a detector. They have a thing which makes visualisations, and it seems it should be possible to build a detector on top of that, but that doesn’t seem to be done yet.

Re: North Korean ICBM launch detected using GPS

#9

>Missiles make ionospheric disturbances that GPS records. The yellow ripple is the ionospheric disturbance. Where can I read more about the meta level concept of "isopheric disturbances"? (Because I suspect I'll find this has been done by military intelligence for a long time then rediscovered by so called "arms control" wonks who insist on putting their code into the public domain.)

Ham radio is actually where you’ll find a lot on the subject. “Band conditions” are determined by the amount of ionospheric disturbance present. For example, meteors entering the atmosphere produce a disturbance that can reflect radio—there are ham radio techniques that exploit this to communicate.

Re: North Korean ICBM launch detected using GPS

#10
post #7

Is it possible someone could explain as if to a small child what data can be collected from GPS which shows this effect. I don't understand.

I don't think I could explain it to a small child, given that I don't have a great understanding of it myself. But here's what I could scrape together based on a linked paper[1]:

You use GPS receivers to detect ionospheric disturbances. Ionosphere, coming from the word "ionized", means it consists of charged particles, positive or negative. (Missile) exhaust is mainly neutral molecules, creating a "hole". These ionospheric holes can be detected through the Faraday Effect[2]. By measuring the Faraday rotation of radio signals (like GPS), you can detect these holes. I think this is similar to how polarized light 3d cinema systems work, except it's the radio spectrum instead of light.

[1] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

[2] https://en.wikipedia.org/wiki/Faraday_effect

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