The Lure and Pitfalls of MIRV

[The Deterrent]

Yes, but dont you think that DGPS correction broadcast could be jammed, especially in the wider vicinity of a tentative target location. Also since the transmitters required will need to broadcast at higher power levels, DGPS broadcast stations could themselves become potential targets via aerial strikes ( SEAD or DEAD type).

Jamming in vicinity of targets doesn't really matters for strategic systems. Primary guidance of INS is always there, being corrected by GNSS, so the error won't amount to much as the system approaches its target.
Tri-services GNSS is a better alternative for a single constellation GNSS or DGNSS.

 

[Falgrine]

Jamming in vicinity of targets doesn't really matters for strategic systems. Primary guidance of INS is always there, being corrected by GNSS, so the error won't amount to much as the system reaches its target.
Tri-services GNSS is a better alternative then a single constellation GNSS or DGNSS.

Every INS has drift and biases, though for military grade IMUs these are comparatively lower. But still if we are talking of navigation over thousands of Km, a simple sensor fusion based on IMU measurements could still lead to a miss. In know GNSS derived pseudo ranges are used in the EKF together with the angle rates and acceleration measurements to correct the increased error in the co-variance matrix and the mean state vector. In the case of GPS loss, the measurement update is solely based on INS data which in the long run could lead to an increase in the estimation error.

What I wanted to provoke in the previous post was the thought that perhaps better solution might be sought after.

Another point with the DGPS is that it is meant to provide corrections for relatively slow moving objects (ships , vehicles). Can it be effectively used for ballistic missiles (speeding at Mach x.yz).

 

[The Deterrent]

Every INS has drift and biases, though for military grade IMUs these are comparatively lower. But still if we are talking of navigation over thousands of Km, a simple sensor fusion based on IMU measurements could still lead to a miss.
I know GNSS is used in EKF together with the angle rates and acceleration measurements to correct the increased error co-variance and the mean state vector. In the case of GPS loss, the measurement update is solely based on INS data which in the long run could lead to an increase in the estimation error.

Thats why I specifically mentioned "as it approaches the target", implying that the corrections to the INS errors will continue to be made by the GNSS till the system reaches the jamming corridor.

What I wanted to provoke in the previous post was the thought that perhaps better solution might be sought after.

By tri-services GNSS, I referred to a receiver capable of receiving GNSS updates from American GPS, Russian GLONASS and Chinese BEIDOU and using the mean results.

Another point with the DGPS is that it is meant to provide corrections for relatively slow moving object (ships , vehicles). Can it be effectively used for ballistic missiles (speeding at Mach x.yz).

Traditionally it is used for slow-moving vehicles, but it can also be used for high-velocity vehicles.

 

[Safriz]

Every INS has drift and biases, though for military grade IMUs these are comparatively lower. But still if we are talking of navigation over thousands of Km, a simple sensor fusion based on IMU measurements could still lead to a miss. In know GNSS derived pseudo ranges are used in the EKF together with the angle rates and acceleration measurements to correct the increased error in the co-variance matrix and the mean state vector. In the case of GPS loss, the measurement update is solely based on INS data which in the long run could lead to an increase in the estimation error.

What I wanted to provoke in the previous post was the thought that perhaps better solution might be sought after.

Another point with the DGPS is that it is meant to provide corrections for relatively slow moving objects (ships , vehicles). Can it be effectively used for ballistic missiles (speeding at Mach x.yz).

In missile firing the one most important thing is accuracy of initial position.
Once position of launch is ascertained accurately, the missile can find its way by using it.
Ballistic missiles will take star reading at apogee anyway and make corrections by steller navigation. After reentry RV cannot receive any signal due to plasma.
So Gps relevance is to find out initial position only.

About Cruise missiles GPS has far more relevance if available. As you may be aware there are two types of GPS signals, Civilian and military. The refresh rate of civilian signal is low and cannot be used for fast moving onjetcs accurately not even subsonic ones. Military grade signal is encrypted,has higher refresh rate and difficult to jam and one has to have permission and necedsary codes from owner country to use it. Pakistan does have military grade signal permission from chinese Beidou, but they have also said that they will shut fown the signal in case of india Pakistan nuclear exchange

 

[Falgrine]

By tri-services GNSS, I referred to a receiver capable of receiving GNSS updates from American GPS, Russian GLONASS and Chinese BEIDOU and using the mean results.

I hope the fusion is being done rather smartly (e.g. using covariance intersection ) than by just taking equally weighted estimates .

 

[Safriz]

I hope the fusion is being done rather smartly (e.g. using covariance intersection ) than by just taking equally weighted estimates .

such receivers are already available commercially which use more than one system. GPS+ GLONASS + some other , Beidou or Galeleo.

 

[war&peace]

We conclude that, based on past experience, and keeping in view the emerging imbalance in resources and access to technology, Pakistan’s most likely choice when faced with the prospect of Indian MIRVs and limited BMD will be the tortoise option.

And now reading the article after Ababeel's test we can see that Pakistan opted for the hare approach and thus the authors failed to encompass all the factor that are driving Pakistan's foray into the next level of weapon delivery systems and ensuring MAD...Pakistan will ensure MAD with India in not so distant future and that will be the new shift in the deterrence philosophy from FSD to MAD.

 

[PaklovesTurkiye]

Jamming in vicinity of targets doesn't really matters for strategic systems. Primary guidance of INS is always there, being corrected by GNSS, so the error won't amount to much as the system approaches its target.
Tri-services GNSS is a better alternative for a single constellation GNSS or DGNSS.

Off topic but...Israelis have developed shield for protecting GNSS systems

https://defence.pk/threads/iai-intr...hardening-gps-systems-against-jamming.475452/

 

[Hakikat ve Hikmet]

And now reading the article after Ababeel's test we can see that Pakistan opted for the hare approach and thus the authors failed to encompass all the factor that are driving Pakistan's foray into the next level of weapon delivery systems and ensuring MAD...Pakistan will ensure MAD with India in not so distant future and that will be the new shift in the deterrence philosophy from FSD to MAD.

You need to get MAD with the most calculative minds in the world...

 

[war&peace]

You need to get MAD with the most calculative minds in the world...

I think Pakistan has already surpassed many of their expectations / calculations with the grace of Almighty Allah

 

[Falcon26]

I had always wondered if Feroz H khan is the same, that is on Pakdef as well

No.

In missile firing the one most important thing is accuracy of initial position.
Once position of launch is ascertained accurately, the missile can find its way by using it.
Ballistic missiles will take star reading at apogee anyway and make corrections by steller navigation. After reentry RV cannot receive any signal due to plasma.
So Gps relevance is to find out initial position only.

About Cruise missiles GPS has far more relevance if available. As you may be aware there are two types of GPS signals, Civilian and military. The refresh rate of civilian signal is low and cannot be used for fast moving onjetcs accurately not even subsonic ones. Military grade signal is encrypted,has higher refresh rate and difficult to jam and one has to have permission and necedsary codes from owner country to use it. Pakistan does have military grade signal permission from chinese Beidou, but they have also said that they will shut fown the signal in case of india Pakistan nuclear exchange

Any evidence to substantiate this claim?

 

[Safriz]

No.



Any evidence to substantiate this claim?

It was widely reported on Pakistani news media a while ago. You can use ur googling skills.

 

[Falcon26]

It was widely reported on Pakistani news media a while ago. You can use ur googling skills.

Haven't been able to find. In the future, please post a link to such claims for the sake of the discussion. Not doubting you but just a friendly reminder.

 

[Safriz]

Haven't been able to find. In the future, please post a link to such claims for the sake of the discussion. Not doubting you but just a friendly reminder.

You can also go through this thread for further reference.
https://defence.pk/threads/pakistan...y-to-deploy-chinas-beidou-gps-network.315538/