This was detected with VLF radio, but I wonder if this kind of event also has an effect on GPS signals? The time-of-arrival of astrophysical gamma rays isn't uniform across the earth.
What I wonder about is all of the technologies that go into ICBM's with nuclear weapons. My layman's guess is that there is active support and collaboration of the NK nuclear program from outside. North Korea is a headache for the US and other western powers, one more thing to consume policy bandwidth and military preparedness. This would seem to be in the interests of China and Russia, and perhaps others. I don't worry too much about the threats that periodically emanate from North Korean; if they start to exceed their utility from the perspective of China and Russia, the needed resources to maintain a viable nuclear program can be quickly shut off. I do hope that I will live to see a "1989" moment in which the North Korean regime is overthrown, and relegated to a horrible and sad footnote in human history.
While Russia and China don’t want to see North Korea collapse as existing nuclear powers they don’t especially want to see other countries acquire nuclear weapons.
Active support and collaboration came from Pakistan, Iran and Libya who were all trying to develop nuclear weapons of their own.
Remember that it took about 10 years for North Korea to go from it's first nuclear weapons test (which fizzled) to something that's probably a deliverable nuclear weapon, and they had spent decades before that to get to the first test. Nuclear weapons require great precision but they're not especially complicated devices. Any nation state, even the very poorest, should have no difficulty designing a nuclear weapon. It's the refinement of the design and the acquisition of the materials that is difficult, and even then the challenge is more in doing it clandestinely. Even then, the cost of the manhattan project, which not only developed two different nuclear weapons in 4 years, but also discovered a lot of the basic underlying physics from scratch, all in secret and with 1940s era equipment cost about $23 Billion adjusted for inflation. Similarly, the development contract for first American ICBM cost about $4 Billion in todays dollars. North Korea benefits from decades of scientific and technological advancement since that time, and it doesn't cost much to employ someone when you can throw their family into a camp, but even if we assume that it nevertheless would cost them as much to develop such technologies, over the course of 30 years that still represents a reasonably small fraction of North Korea's GDP. North Korea's long history of failures are pretty clear evidence that they were not given the design and manufacturing capability necessary to produce working nuclear weapons or missile systems. While no doubt there has been communication with other state actors over the decades, the idea that they are receiving active support is not at all supported by evidence, and indeed the embarrassingly long development time implies that either there is a great deal of incompetence in the development effort, active sabotage, or likely both.
GPS signals go through the ionosphere on their way from the satelites. The ionosphere causes distortions in the signal. If you want to achieve the best navigational accuracy you need to account for these distortions.
These distortions are not constant. They change from time to time. There are many different ways to account for them. One of the most accurate solution is to keep a GPS receiver on a well known location. Since you know that this receiver haven’t moved you can use the signal measured to estimate the parameters of the ionosphere between that station and the satelite.
Normally these signals are used to correct GPS navigational solutions. You take the closest station to your moving receiver and assume that whatever way the ionosphere was distorting for that station will do the same for your receiver too. This is valuable so there are network of such GPS stations in a lot of places.
Here they use the data collected by these stations differently. Instead of correcting a navigational solution they visualise the measured state of the ionosphere as seen by a bunch of these stations.
GPS receivers work by figuring out how far away they are from a number (>3) of GPS satellites. The receiver knows where the GPS satellites are (since the satellites broadcast their orbit parameters) so if a receiver knows how far it is from several satellites it can work out where it is itself.
Now, as the GPS satellite signals travel through Earth's atmosphere, they can be slowed down by different atmospheric effects. A slower signal will cause the receiver to think it's farther away from a satellite than it really is, so the receiver might estimate that it's position has changed a little bit. However, if you know the receiver's position hasn't change (maybe it's fixed in place to a big rock), then you can attribute the receiver's measured "change in position" to a change in atmosphere characteristics.
In this paper, they seem to have lots of fixed GPS receivers all over the place. By looking at all of them together, they can make a sort of map of the atmosphere characters in a part of the sky that's affected by rocket launches. The authors see these big ripples emanating from a Falcon Heavy launch in the US and this tweet shows those same ripples emanating from a launch site in North Korea.
Fun house mirrors are curved and distort your reflection.
Some fun house mirrors are flexible so they can get pushed or pulled which will make you look taller or shorter or fatter or skinnier than you know you are.
By observing the difference between how you appear compared with how you are;
you can learn something about how the flexible mirror is being curved.
How this works in the fun house is there is you the mirror and LIGHT.
Both you and the light are well known and easy to predict; light will travel straight(ish) and you will not suddenly become very very short, so the thing that is changing your appearance is the flexible mirror.
In the GPS rocket case,
the GPS satellites are the illuminating source corresponding to the light in the room sending out radio (electromagnetic radiation same as light just at longer wavelengths)
The ground station GPS receivers correspond to your eyes (they know what they *should* see).
The earth's ionosphere corresponds to the flexible fun house mirror.
taken together, the same way you could tell if something we can't see behind the mirror flexed it, the author of the post showed they can tell if, when and where
an unannounced rocket goes through the ionosphere.
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.
As you walk past a school you yell with your voice, your friend nearby knows what you sound like but he hears you differently because your voice also bounces off the school wall. He adjusts the sound based on what you should sound like, the leftover bit is the shape of the wall.
You can figure out if someone moved a brick (or launched a missile) because your voice changes when it reaches your friend and he needs to apply a new change to get your voice back.
We can see the signal changes the rocket causes to the ionosphere and know that it's happened.
Isn't the ionosphere already past the burn-out phase of a ballistic missile? I.e. by the time the rocket gets there it is just a glorified harpoon. Or perhaps that doesn't matter as anything of this size travelling at this speed would cause detectable disturbance?
Fun fact: the arecibo radio telescope was funded to study ionosphere disturbances so the US military could explore the possibility of detecting ICBMs passing through the ionosphere. To my knowledge no such system was actually built but apparently it wasn't as ridiculous a proposal as I thought.
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.
The problem is that NK has thousands of traditional artillery pieces stationed along the DMZ that are capable of hitting Seoul and other large population centers [0]. They also have short range ballistic missiles [1] which can reach much of South Korea.
So negotiating with them has been dicey. Especially since they have figured out that "If we do this thing the west doesn't like, we can go to the negotiating table and get them to send us food."
I do want to point out that the war never ended in 1953 - there was just an armistice signed, so technically North and South Korea are still belligerents.
So far as the DPRK leadership acting rationally - by their standards, they are. From talking with people who have visited there - the North Koreans have a world view that is substantially different from everyone else on the planet.
Even assuming it's not already too late for that: what could they do? NK is already sanctioned to the max. And the few leavers that they can still pull probably wouldn't be enough to stop them at this point. And them being so close to China and SK makes any direct military action against them likely to trigger WW3.
They very likely already have that.. they’ve detonated >50kt nukes and have mobile ICBM launchers that have demonstrated rockets with thousands of miles of range.
They could almost certainly detonate a nuclear weapon in Korea or Japan. I’d put even odds on a strike on Guam, but probably not quite capable of hitting Western US.
>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.)
========
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.
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.
perihelions|3 years ago
https://gcn.gsfc.nasa.gov/gcn3/32744.gcn3 ("GRB221009A: Detection as sudden ionospheric disturbances (SID)")
https://www.qsl.net/df3lp/grb221009/KLM_grb221009a_magnitude... (from the above link)
http://abelian.org/vlf/grb221009a-DHO.png
http://abelian.org/vlf/grb221009a-NAA.png
http://abelian.org/vlf/grb221009a-NSY.png
[0] https://news.ycombinator.com/item?id=33215572 ("Record-breaking gamma-ray burst possibly most powerful explosion ever recorded")
This was detected with VLF radio, but I wonder if this kind of event also has an effect on GPS signals? The time-of-arrival of astrophysical gamma rays isn't uniform across the earth.
gregfjohnson|3 years ago
laurencerowe|3 years ago
Active support and collaboration came from Pakistan, Iran and Libya who were all trying to develop nuclear weapons of their own.
https://rusi.org/explore-our-research/publications/commentar...
walrus01|3 years ago
https://www.google.com/search?client=firefox-b-d&q=aq+khan+p...
https://en.wikipedia.org/wiki/Abdul_Qadeer_Khan
Yes there was a great deal of outside help with their enrichment and weapons design.
aredox|3 years ago
They don't need outside help.
jjk166|3 years ago
krisoft|3 years ago
beardyw|3 years ago
krisoft|3 years ago
These distortions are not constant. They change from time to time. There are many different ways to account for them. One of the most accurate solution is to keep a GPS receiver on a well known location. Since you know that this receiver haven’t moved you can use the signal measured to estimate the parameters of the ionosphere between that station and the satelite.
Normally these signals are used to correct GPS navigational solutions. You take the closest station to your moving receiver and assume that whatever way the ionosphere was distorting for that station will do the same for your receiver too. This is valuable so there are network of such GPS stations in a lot of places.
Here they use the data collected by these stations differently. Instead of correcting a navigational solution they visualise the measured state of the ionosphere as seen by a bunch of these stations.
thatcherc|3 years ago
GPS receivers work by figuring out how far away they are from a number (>3) of GPS satellites. The receiver knows where the GPS satellites are (since the satellites broadcast their orbit parameters) so if a receiver knows how far it is from several satellites it can work out where it is itself.
Now, as the GPS satellite signals travel through Earth's atmosphere, they can be slowed down by different atmospheric effects. A slower signal will cause the receiver to think it's farther away from a satellite than it really is, so the receiver might estimate that it's position has changed a little bit. However, if you know the receiver's position hasn't change (maybe it's fixed in place to a big rock), then you can attribute the receiver's measured "change in position" to a change in atmosphere characteristics.
In this paper, they seem to have lots of fixed GPS receivers all over the place. By looking at all of them together, they can make a sort of map of the atmosphere characters in a part of the sky that's affected by rocket launches. The authors see these big ripples emanating from a Falcon Heavy launch in the US and this tweet shows those same ripples emanating from a launch site in North Korea.
tejtm|3 years ago
Some fun house mirrors are flexible so they can get pushed or pulled which will make you look taller or shorter or fatter or skinnier than you know you are.
By observing the difference between how you appear compared with how you are; you can learn something about how the flexible mirror is being curved.
How this works in the fun house is there is you the mirror and LIGHT.
Both you and the light are well known and easy to predict; light will travel straight(ish) and you will not suddenly become very very short, so the thing that is changing your appearance is the flexible mirror.
In the GPS rocket case, the GPS satellites are the illuminating source corresponding to the light in the room sending out radio (electromagnetic radiation same as light just at longer wavelengths)
The ground station GPS receivers correspond to your eyes (they know what they *should* see).
The earth's ionosphere corresponds to the flexible fun house mirror.
taken together, the same way you could tell if something we can't see behind the mirror flexed it, the author of the post showed they can tell if, when and where an unannounced rocket goes through the ionosphere.
chmod775|3 years ago
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
jvm___|3 years ago
You can figure out if someone moved a brick (or launched a missile) because your voice changes when it reaches your friend and he needs to apply a new change to get your voice back.
We can see the signal changes the rocket causes to the ionosphere and know that it's happened.
ilyt|3 years ago
H8crilA|3 years ago
jjk166|3 years ago
amelius|3 years ago
krisoft|3 years ago
noobhack|3 years ago
[deleted]
ransom1538|3 years ago
[deleted]
chiph|3 years ago
So negotiating with them has been dicey. Especially since they have figured out that "If we do this thing the west doesn't like, we can go to the negotiating table and get them to send us food."
I do want to point out that the war never ended in 1953 - there was just an armistice signed, so technically North and South Korea are still belligerents.
So far as the DPRK leadership acting rationally - by their standards, they are. From talking with people who have visited there - the North Koreans have a world view that is substantially different from everyone else on the planet.
[0] https://en.wikipedia.org/wiki/M-1978_Koksan
[1] https://en.wikipedia.org/wiki/KN-25
samus|3 years ago
jasonwatkinspdx|3 years ago
rafael09ed|3 years ago
ravenstine|3 years ago
https://www.youtube.com/watch?v=vEgE4R_6fLU
mikeyouse|3 years ago
They could almost certainly detonate a nuclear weapon in Korea or Japan. I’d put even odds on a strike on Guam, but probably not quite capable of hitting Western US.
vkou|3 years ago
Neither the Iraq nor Ukraine conflicts would have happened if they were nuclear states.
An armed society is a polite society, or so I've been told many, many times.
darepublic|3 years ago
dontbenebby|3 years ago
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.)
krisoft|3 years ago
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.
Xylakant|3 years ago
======== 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.
teeray|3 years ago