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New laser could cram GPS alternative into a shoebox

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Re: New laser could cram GPS alternative into a shoebox

#41

Post by jfengel »

KennyBlanken wrote: post #7
master_crab wrote: post #2

Sadly, the first applications of this will most likely be military.

More specifically, nuclear arms, where the budget is "there is no budget." Just the inertial guidance system of a 90's-era ICBM cost over six figures per missile. The ability to precisely place a missile without any external navigation (except for stars.) Once it gets cheap enough, it'll probably go into cruise missiles; it could eliminate or reduce the need for terrain contour matching, which requires radar transmis…

In Russia's case, there does appear to be "no budget". The weapons were intended as a last resort, and so they are a great target for diverting maintenance funds.

It's not quite so bad as "we are certain that they will not successfully launch any nukes" and so they're still being treated with caution. But the US keeps upping what it allows Ukraine to do as it loses its fear of World War III.

As it applies to the US... yeah, the sky is the limit for military spending.

Re: New laser could cram GPS alternative into a shoebox

#42

Post by horstbort »

master_crab wrote: post #2

Sadly, the first applications of this will most likely be military.

Thankfully, the same measurement technique can be used to measure e.g. gravitational fields, and there are already devices available on the market which surpass classical gravimeters in accuracy and precision. There are also satellite missions in the planning to map Earth's gravitational field with atom interferometry.

Re: New laser could cram GPS alternative into a shoebox

#44

Post by red75prime »

Majromax wrote: post #12
swayvil wrote: post #3

An ultra sensitive motion sensor. Intriguing. Could one derive the Earth's rotation? The motion of the solar system? By watching vibrations could it be a microphone?

> Could one derive the Earth's rotation? Yes, existing gyroscopes are sensitive enough for that. In 1966, one of the first Soviet attempts to launch the Soyuz failed on the pad because the guidance system remained active after a scrubbed launch attempt. After a couple of hours, the Earth had rotated enough such that the guidance system thought it was off-course, triggering the still-armed launch escape system. > The…

> that the galaxy's gravitational acceleration on the solar system is on the order of 10^-10 m/s

A free falling accelerometer (that is an accelerometer that moves along a spacetime geodesic) will detect no acceleration. And the solar system "free-falls". I don't see how we can detect that.

Re: New laser could cram GPS alternative into a shoebox

#45

Post by IshKebab »

2OEH8eoCRo0 wrote: post #23
ajuc wrote: post #20

The main application would obviously be missiles and autonomous military drones. If you can use GPS - you should. It's crazy cheap and it doesn't accumulate errors over time. But in a war GPS can be jammed. This can't.

Lot's of Western weapons already combine INS and GPS. I suppose this could be a better alternative to INS. https://en.wikipedia.org/wiki/AGM-158_JASSM > Guidance system: GPS, INS, IIR

This is inertial navigation. It's just much more accurate than existing systems.

Re: New laser could cram GPS alternative into a shoebox

#46

Post by roywiggins »

littlestymaar wrote: post #13
KennyBlanken wrote: post #7

Earlier quoted context omitted.

More specifically, nuclear arms, where the budget is "there is no budget." Just the inertial guidance system of a 90's-era ICBM cost over six figures per missile. The ability to precisely place a missile without any external navigation (except for stars.) Once it gets cheap enough, it'll probably go into cruise missiles; it could eliminate or reduce the need for terrain contour matching, which requires radar transmis…

Nuclear arms doesn't need as much accuracy as other weapons though: when using a cruise missile or a glide bomb with a few hundreds of kilograms of explosives, you need metric precision to get the military effect, when the payload is a 100kt bomb, then 100m is accurate enough. Unlike other bombs it must absolutely be 100% resilient to any kind of spoofing though, for obvious reasons, hence GNSS is a nonstarter for th…

It makes a difference for hard targets, see the new nuclear "super-fuzes."

It can take several warheads to destroy a missile silo with high probability, because even landing a little off-target can spare the silo. Greater precision means it takes substantially fewer.

https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...

Re: New laser could cram GPS alternative into a shoebox

#47

Post by hi-v-rocknroll »

master_crab wrote: post #2

Sadly, the first applications of this will most likely be military.

This is truism applicable to the vast majority of technologies. Space was once also a rival mother of invention.

If quantum INS can soon take out more Russian ammo dumps in spectacular fashion, then bring on improvements to lasers.

Re: New laser could cram GPS alternative into a shoebox

#48

Post by dgroshev »

jfengel wrote: post #41
KennyBlanken wrote: post #7

Earlier quoted context omitted.

More specifically, nuclear arms, where the budget is "there is no budget." Just the inertial guidance system of a 90's-era ICBM cost over six figures per missile. The ability to precisely place a missile without any external navigation (except for stars.) Once it gets cheap enough, it'll probably go into cruise missiles; it could eliminate or reduce the need for terrain contour matching, which requires radar transmis…

In Russia's case, there does appear to be "no budget". The weapons were intended as a last resort, and so they are a great target for diverting maintenance funds. It's not quite so bad as "we are certain that they will not successfully launch any nukes" and so they're still being treated with caution. But the US keeps upping what it allows Ukraine to do as it loses its fear of World War III. As it applies to the US..…

There is no fear of WWIII, that's part media invention, part political excuse, part useful idiots. A "World War" requires an opponent worthy of a world-wide conflict, and Russia is anything but, being stuck in Ukraine for three years and losing most of its army in the process. Conventionally, Russia is no match for NATO, with enough political will it'd be a Desert Storm-like curb stomp. The only way it's not is the US abandoning NATO, then it can be quite painful, but even then Russian economy is no match for the EU.

As for nuclear weapons, they are practically useless. Anything but strategic use would have little impact on the battlefield, but will immediately alienate China and India. They have their own border conflicts and do NOT want the nuclear taboo to be broken, and they are holding the leash, being the only economic and technological lifeline Russia has. A strike against the US would be suicidal for obvious reasons.

Also, notice how Putin and his officials talk about nuclear use a lot, but there is still zero evidence of any action (such as dispersal of road-based ICBMs or 12th GUMO taking warheads out of storage). Rhetoric is cheap and not credible.

The only real fear of escalation here is "horizontal" escalation: Russia stirring shit elsewhere. Advanced anti-ship missiles to Houthis, handing nuclear technology to North Koreans or submarine technology to China, that kind of thing. But that's already seem to be happening, and there isn't much more that Russia can do.

Re: New laser could cram GPS alternative into a shoebox

#49

Post by hi-v-rocknroll »

2OEH8eoCRo0 wrote: post #23
ajuc wrote: post #20

The main application would obviously be missiles and autonomous military drones. If you can use GPS - you should. It's crazy cheap and it doesn't accumulate errors over time. But in a war GPS can be jammed. This can't.

Lot's of Western weapons already combine INS and GPS. I suppose this could be a better alternative to INS. https://en.wikipedia.org/wiki/AGM-158_JASSM > Guidance system: GPS, INS, IIR

INS incl. LRG has been a thing for decades. The modern problem is over-reliance on GPS (military coded and commercial). QINS would solve many issues but GNSS is also still needed to calibrate the system at least initially (at launch) and opportunistically mid-course. The other thing that is being fielded, despite its downsides and vulnerabilities, is wire guidance a-la TOW.

Re: New laser could cram GPS alternative into a shoebox

#50

Post by talldayo »

KennyBlanken wrote: post #31
ceejayoz wrote: post #24

Earlier quoted context omitted.

Yes, but until they’re autonomous the drones are still heavily subject to jamming of their radio controls. This won’t fix that. HIMARS, on the other hand, will enjoy the improvements.

"Until"? They've been in use for years now in that war. The Shahed drone, for example, was used by Russia. About two years ago Ukraine was using autonomous drones to down Shahed drones. AI targeting came out in the Gulf war, friend. 35 years ago, Tomahawks could use rudimentary AI to match preprogrammed terrain profile and target imagery to get more precise targeting.

The Shahed drone can't use it's INS system to communicate with a ground operator or reprogram itself. As the other comment says, it's basically a glorified cruise missile that has the autonomy of a Roomba. Disabling a Shahed with another drone may have happened, but it's certainly not the primary threat to the Shahed when compared to CIWS or SAMs.

AI targeting was debuted in the Patriot missile system, which does technically field the required elements of a hands-off kill chain. But TERCOM is not AI nor was it debuted in the 90s with the TLAM. The original BLOCK-I variants of the Tomohawk (and many versions released afterwards) were no more autonomous than the Shahed-136.

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