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I am not sure where to ask this question but here it is. There is the company that is making Inertial Navigation Systems for submarines and it claims to have a position accuracy with no aiding of 1Nm/12h so 1 Nautical meter every 12 hours.

That seems insanely good and they even have one which is apparently 1Nm/360h, now I should mention that the device is military grade quality and is 40kg heavy.

I'm not an expert thus the question, but this is pretty much sufficient to even considering removing GPS from the geolocalisation process no?

Transistor
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stefan
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INS needs to be calibrated so it knows what the initial velocity is before it can start to accumulate the acceleration it's measuring. Verifying that velocity in the open ocean is easier when you have a known position.

Even if you solved that what would you actually save by not having a GPS module on board? They can be had for less than $10 for something civilian grade. You only need some way for it to receive the satellite's signal.

If you mean pulling all gps satellites out of orbit because the original goal of them is no longer needed?

First not all there are a few extra sets of GNSS each managed by another entity. So there's going to be satellite-based positioning information available regardless of what the US wants.

Second other industries use gps extensively. They will get very angry if their GPS modules stop working all of a sudden.

ratchet freak
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This is not an engineering issue, it is a navigation issue.

Military-grade inertial navigation systems (like an ESGN) have been meters-over-a-month accurate for at least 40 years. In practical terms, a vessel so-equipped would not need an external fix (determination of position) over an entire voyage, even one months long. That, however, does not remove the requirement for obtaining external fixes. Failure to take external fixes is what led to the USS Atlanta (SSN-712) verifying that fixed objects (like Gibraltar) are stronger than even nuclear submarines. They thought the specifications of their inertial navigation was sufficient; it was not.

Submarines must use their inertial systems and dead reckoning to determine their position while submerged. These are vessels traveling at 10-25+ knots while essentially blindfolded, because sonar only keeps you from hitting things that make noise. Navigation standards do not allow using solely internal sources to set the vessel's position. There are too many ways errors can creep into any internal system, and the result of being wrong can be catostrophic. So the ship's inertial position is periodically reset via external systems, such as GPS. GPS is extremely accurate, but is not the only method available, Satellite Navigation (SatNav) being the other primary method (uses doppler calculations from moving satelites). These will be used to reset the ship's inertial systems to the latest fix. In the absence of electronic aids, celestial navigation is also available, along with terrestrial (visual) fixes if close to land.

So no matter how good commercially available inertial navigation systems are, a source for external fixes is always required.

Source: my US Navy officer's qualification in submarines (gold dolphins).

Tiger Guy
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Inertial Navigation Solutions for navies lists Marins M3 INS at 1NM/12hrs (note capital M) accuracy. Best being Marins M11 at 1NM/360hrs.

Marins Series enables stealth autonomous navigation for submarines, providing very accurate heading, roll, pitch, speed and position. These products also uniquely address the need for advanced naval surface vessels, operating under severe GNSS-denied environment.

The NM stands for nautical mile, not nautical meter, which does not exist, 1 NM = 1.852 km.

Optical based INS systems to navigate if GPS systems are jammed.

StainlessSteelRat
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