If GPS system is completely disable what kind of weapon and sensors can still be used?

Submarines nowadays take a sonar image of the seafloor and compare that to their charts to correct for inertial drift but the Royal Navy has been trialling a Quantum gyroscope thats 1,000 times more accurate than a laser ring and only drifts by 1 meter every 24 hours. Its the size of a mini fridge though and reliant on freezing Rubidium gas to near absolute zero (where quantum effect kicks in and the Rubidium atoms stop acting as individual particles and instead act as a wave) so I doubt it will be miniaturised enough to work on missiles.
 
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Submarines nowadays take a sonar image of the seafloor and compare that to their charts to correct for inertial drift but the Royal Navy has been trialling a Quantum gyroscope thats 1,000 times more accurate than a laser ring and only drifts by 1 meter every 24 hours. Its the size of a mini fridge though and reliant on freezing Rubidium gas to near absolute zero (where quantum effect kicks in and the Rubidium atoms stop acting as individual particles and instead act as a wave) so I doubt it will be miniaturised enough to work on missiles.
Got any more details on that quantum gyro?
 
Submarines nowadays take a sonar image of the seafloor and compare that to their charts to correct for inertial drift but the Royal Navy has been trialling a Quantum gyroscope thats 1,000 times more accurate than a laser ring and only drifts by 1 meter every 24 hours. Its the size of a mini fridge though and reliant on freezing Rubidium gas to near absolute zero (where quantum effect kicks in and the Rubidium atoms stop acting as individual particles and instead act as a wave) so I doubt it will be miniaturised enough to work on missiles.
A gyro only measures attitude. It does not measure position, An INS has gyros and accelerometers. It is the accelerometers that do most of the position sensing.
 
Terrestrial/airborn radio beacons can replace GPS with lower cost and higher power, with only problems of coverage. At tactical ranges, unless you need a full passive solution it should be the easiest and cheapest option I'd think.
Nah, there is no replacing GPS. TACAN, VOR ands LORAN are all shells of themselves.
 
eLORAN eternally getting kicked down the road meanwhile Chayka just chugs along.
 
A gyro only measures attitude. It does not measure position, An INS has gyros and accelerometers. It is the accelerometers that do most of the position sensing.

Accelerometers only work in 2D, they can measure duration and force of acceleration to calculate distance of travel but are wildly inaccurate for measuring direction of travel, particularly when a craft has full freedom of movement across all planes, thats why you have Gyroscopes. The fun thing with a quantum gyroscope though is you dont need separate accelerometers as the probe laser can measure both direction and acceleration simultaneously from the same atom cloud.
 
Can you point me to any current systems so I could learn more?
They all basically cheap modern version for Satallite positioning, specifically cubesats. And work very similar to the star tracker on the like of ICBMs.

You can buy one for bout 5k to 35k depending the model and how long you want it to last in space.

Theres also star tracking programs you can get for you phone that recognize the stars just by pointing the camera at the night sky.

Lots of small things that make me believe that a modern A-INS be very small, simple, and cheap to make. Smarter people then me could likely make one out of an old smart phone since those have all types of gyros in them for measuring angles.
 
Accelerometers only work in 2D, they can measure duration and force of acceleration to calculate distance of travel but are wildly inaccurate for measuring direction of travel, particularly when a craft has full freedom of movement across all planes, thats why you have Gyroscopes. The fun thing with a quantum gyroscope though is you dont need separate accelerometers as the probe laser can measure both direction and acceleration simultaneously from the same atom cloud.
This is so wrong. There are at least 3 in every INS and they measure in all 3 axis. These are very accurate in any direction. This is what every rocket, missile, launch vehicle and spacecraft have. And I said they are paired with gyros in an INS.

Quantum gyros do not exist commercially nor do they sense acceleration (motion)
 
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NIST scientists are exploiting the effects of inertia on the atomic scale to develop exquisitely sensitive, intrinsically accurate motion sensors.

Initially, atoms are cooled and trapped within a glass vapor cell. When the trap is turned off, the atoms begin to expand outward and are excited by laser beams that put each atom into two quantum states at the same time. As the atoms disperse and interact while the cell is in motion, the atoms’ states change differently depending on the direction and strength of the forces caused by rotation or acceleration of the cell.
Each atom’s two quantum states can be imagined as rippling waves. The waves of the atoms reinforce or cancel each other out at various points in the cell to form new interference patterns. This interference determines the atom’s final quantum state and appears as “fringe” patterns projected onto a detector. From those patterns, researchers can deduce acceleration in one direction and rotation in two directions.


230517-quantum-accelerometer-navy-040-2_1685032688580_x2.jpg
 




230517-quantum-accelerometer-navy-040-2_1685032688580_x2.jpg
Sounds like the NIST sensor works a little bit differently than the Imperial one.

You'd still need 3x units mounted at 90deg to each other to cover the full sphere of movement, and the need for cryogenic cooling complicates matters for reducing the size of the overall package.
 



 
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If GPS is disabled, could the introduction of eLORAN be a remedy? Could this old venerable system with some modern anti-jam updates of its transmission protocols effectively substitute the GPS in the future? LORAN was used on aircraft in Nam for navigation and weapons delivery.
 
UK MoD is currently engaging with industry on an eLORAN system. But the understanding is its future role would be a domestic airspace backup, it wouldn't be suitable for an offensive role as the enemy could spoof it.
 
What's the status of the old long range navigation systems like LORAN-C? IIUC there's been a bit of renewed interest in eLORAN as a backup to GPS and I think there are still TACAN beacons at airfields, but what else is out there that could be added to on-board INS to increase the accuracy of navigation over longer ranges.

As an aside, what happens to INS when an aircraft receives and update from an outside navigation reference like GPS or eLORAN? Does the INS reset as if it was in the hangar at home base, and drift starts again.
 
No they dont alter its output. The aircraft/weapons computer will judge which it considers a more reliable out of available sources of INS/GPS/terrain imaging on a weighting system, and if they drift too far apart it will disregard one. E.g. If there was a slow drift of a few cm in GPS compared to INS it would consider the GPS more reliable, but if the GPS position suddenly jumped several km in less than a minute it would likely consider the INS data more reliable. If the GPS and terrain imaging positioning were closely aligned but the INS was suddenly way off it would disregard the INS, etc..
 
As an aside, what happens to INS when an aircraft receives and update from an outside navigation reference like GPS or eLORAN? Does the INS reset as if it was in the hangar at home base, and drift starts again.
Effectively, yes that's what happens normally.

You get a new fix that's more accurate than what your INS can be so you tell the INS "now at this location, restart positional drift".

I'm not solid on the details at the inside-the-box level, but operationally you reset the position and restart counting drift.
 

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