Artillery: News & Discussion

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Bharadwaj
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Re: Artillery Discussion Thread

Post by Bharadwaj »

The ALL FAT with the neptune engine will have no issues dragging a extra couple of tonnes up a mountain...
ramana
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Re: Artillery Discussion Thread

Post by ramana »

More videos of the PGK fuze

PGK Over view



and sequence of operations

Not how the fuze is set



I think India should import 5000 fuzes as part of Mountain Strike Corps Artillery M-777.
This will be a huge force multiplier.

Meantime ARDE can accelerate their verrsion.
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Re: Artillery Discussion Thread

Post by shiv »

The fuze is only one half of the thing isn't it? Something has to mark or illuminate the target.
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Re: Artillery Discussion Thread

Post by Singha »

ppl are also moving enmasse to laser guided rockets for helicopters than just up the round count. the launch heli can rotate its optronics ball to the side and keep lasing for the <=5 seconds it take in flight
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Re: Artillery Discussion Thread

Post by Indranil »

shiv wrote:The fuze is only one half of the thing isn't it? Something has to mark or illuminate the target.
No illumination required. It is GPS guided.
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Re: Artillery Discussion Thread

Post by Singha »

i assume some form of laser device + laptop + radio or spotter with digital map + radio gives the GPS co-ordinates to the firing crew ? a mere mortar will not be attacking with the benefit of pre loaded GPS ords unlike a JDAM
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Re: Artillery Discussion Thread

Post by abhik »

Singha wrote:ppl are also moving enmasse to laser guided rockets for helicopters than just up the round count. the launch heli can rotate its optronics ball to the side and keep lasing for the <=5 seconds it take in flight
...
There are at least half a dozen companies that have developed such rocket guidance kits, and same for fuze based artillery guidance kits. We as usual are late to the game, though looks like 70mm laser guided rocket may be taken care of by a 'Make in India' programme :x .
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Re: Artillery Discussion Thread

Post by ramana »

shiv wrote:The fuze is only one half of the thing isn't it? Something has to mark or illuminate the target.

It's GPS guided. So some sort of binoculars that give the GPS coordinates of the target by a spotter. And these are passed on to the fuze setter before the round gets ready for use.

At least for the M777 guns for use in the mountain these fuzes would help the ammo logistics trail.

Mean time ARDE developed fuzes can be the long term solution.

Now I understand the strange tender from OFB to have multiple requirements all in one fuze that other suppliers were complaining.
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Re: Artillery Discussion Thread

Post by darshhan »

Singha wrote:i assume some form of laser device + laptop + radio or spotter with digital map + radio gives the GPS co-ordinates to the firing crew ? a mere mortar will not be attacking with the benefit of pre loaded GPS ords unlike a JDAM
You are right. It is mostly the special forces/ghatak type who exploit the gaps between the lines and identify the targets for the PGMs delivered by artillery, mortars or airforce. If it is a laser guided munition they have to illuminate using laser designator. If it is a gps guided weapon they have to feed the coordinates. They do the same for JDAMs.

The coordinates have to be sent carefully. Hamid karzai himself survived a friendly fire accident that resulted from wrong coordinates being sent to a JDAM. Three US special forces were killed in the incident. This is from 2001 when US dislodged taliban after sept 11 attacks
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Re: Artillery Discussion Thread

Post by Aditya G »

SBajwa wrote:Can we use PGM against specific targets like house of JEM chief in Bahawalpur or house of Hafiz suar at Muridke?
We can achieve that even today with Popeye/Crystal Maze, KH-59 etc

I dont think this is a question of technology, but more of will.
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Re: Artillery Discussion Thread

Post by shiv »

Pardon my stupidity. Even ordinary unguided mortars and artillery are guided by spotters. As per the recollection of a special forces operative who saw action in Sri Lanka - the correction that can be applied for mortars is as little as 25 meters.

The GPS coordinates have to be produced first and then fed in to the individual artillery/mortar shell after which it could probably hit a static pinpoint target with the level of accuracy of GPS - which is (as per what I read for SDBs) a CEP of 10 meters - that means 50% outside 10 meters

So exactly what does this achieve if it requires a spotter/GPS marker and is barely more accurate than standard artillery with a spotter. I am guessing that this has to go hand in hand with at least a UAV.
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Re: Artillery Discussion Thread

Post by brar_w »

Shiv, the operational test verified CEP of the Excalibur is much better than the 10 m. Regardless, you are correct forward positioned observers will constantly adjust/direct the fires being provided based on observations but the CEP for conventional artillery shells is still significantly larger which is not desirable if you are in a danger close situation or you are in an urban environment and need to provide fires support in close proximity to civilians or friendly forces. On top of this these fuzes have 'fail safes' built into them in case there is a greater than anticipated error (for PGK it is 150 meters) or if the fuze fails to acquire a GPS signal. Under such cases the round will follow a ballistic trajectory and impact as a dud. This has allowed them to confidently employ the system with very close proximity to friendly forces. In Iraq, the M982 was used in instances where friendly infantry was within 50 meters of the target. With conventional rounds it is unlikely that they would consider bringing artillery fires in such a dense environment unless they can move the troops further back.
The most significant Western purpose-designed guided artillery projectile on the market is the 155 mm M982 Excalibur (a joint project between Raytheon and BAE Systems Bofors), which costs in the region of five times as much as a PGK-equipped shell but officially has a CEP of about 5 m (in practice it is said to commonly strike within 2 m of the target). As a result, US forces prefer the Excalibur where high precision is required.
Excalibur is an extended-range, autonomously guided projectile using a combination of high-glide-ratio, lifting-body airframe and tightly coupled GPS/inertial measuring unit (GPS/IMU) guidance to achieve ranges of up to 37.5 km with a high degree of precision from both the US Army's M109A6 Paladin SP gun and 155 mm/39-calibre M777 towed artillery system. LINK
Excalibur Testing: Threshold, Objective requirement, and the demonstrated performance in testing -

Image

As for the PGK, below are excerpts from its operational test and evaluation -
PGK is accurate. It demonstrated a circular error probable (CEP) of 13.0 meters during IOT&E and 10.0 meters when data from the lot acceptance testing are included with an upper 90 percent confidence bound of 20.9 meters. These results are better than the threshold and objective accuracy requirements of 50 and 30 meters, respectively. Further, PGK is more accurate than conventional HE projectiles at all ranges and PGK accuracy increases with range because of the longer time of flight in which guidance corrections can be made.

The lethality of M795 HE projectiles and M549A1 HE RAP, when fuzed with PGK, remains unchanged from the lethality of these projectiles when fuzed with conventional artillery fuzes. The employment of PGK fuzes on these projectiles improves achieved effects on the target by guiding each projectile closer to its intended target, thus making more efficient use of the projectile’s current lethality.

Image
The portion in bold probably runs opposite of what happens with conventional artillery where miss distances are likely to be larger at the very extreme of the range envelope given the shells have no ability to adjust while in flight. A forward observer will provide input, allowing adjustments but the rounds themselves do not have any way to correct for errors or adjust while in flight. On the previous page are some estimates of how many rounds are required for different target sets depending upon the accuracy of the round.
darshhan wrote:
Singha wrote:i assume some form of laser device + laptop + radio or spotter with digital map + radio gives the GPS co-ordinates to the firing crew ? a mere mortar will not be attacking with the benefit of pre loaded GPS ords unlike a JDAM
You are right. It is mostly the special forces/ghatak type who exploit the gaps between the lines and identify the targets for the PGMs delivered by artillery, mortars or airforce. If it is a laser guided munition they have to illuminate using laser designator. If it is a gps guided weapon they have to feed the coordinates. They do the same for JDAMs.

The coordinates have to be sent carefully. Hamid karzai himself survived a friendly fire accident that resulted from wrong coordinates being sent to a JDAM. Three US special forces were killed in the incident. This is from 2001 when US dislodged taliban after sept 11 attacks
Class I and II UAS's play a significant role in the modern battlefield :
In the first scenario, the Raven B was flown to a suspected target area. Once positive identification (PID) of the target was confirmed via video feed into the GCS, the operator centered the crosshair available in the UAS viewfinder on the target and took a snap shot of the target. He explained that once this snapshot was taken, the software in the GCS took the position of the Raven B at the time the image was taken and using the laser range finder calculates the distance from the Raven to the target based on where the crosshairs were centered when the snapshot was taken. The slant range or slope from the UAS to the target was calculated. The calculation provided a 10-digit grid to the target itself or where the crosshairs were centered when the snapshot image was taken. The target location and a description of the target were then sent to the CAS platform via voice communications. Due to airspace collision potential between the manned and unmanned aircraft, the UAS was flown out ofthe CAS attack area. Once the target was attacked by the manned CAS platfol1n, the UAS was then flown back over the target area for battle damage assessment (BDA).

The second scenario involved the identification ofthe target by the Raven B and like in the first scenario, a 10-digit grid was provided after a snapshot was taken of the target. This 10-digit grid was then sent to the fire direction center (FDC) at the artillery unit. The artillery unit sent one adjusting round. There is no area de-confliction required during artillery fire when utilizing the a Group I UAS according to DeVeau; therefore, when the forward observer or unit controlling fires receives "splash"from the artillery FDC, the operator of the UAS starts looking for the impact of the adjustment round. When the impact becomes visible,·another snapshot is taken with the crosshairs placed over the center of the impact. There are two options from this point.

In the first option, the UAS operator passes the grid of the round impact to the FDC as a laser adjustment mission and lets the Advance Field Artillery Tactical Data System (AFATDS) do the calculating to provide the new data for the next round to the gun-line. Thls is how full size manned aircraft would conduct the call for fire if they were doing laser spotting from the air. The second option is for the UAS operator to acquire the 10-digit grid provided by the UAS for the adjustment round and let software in the GCS make the calculations to provide the appropriate left, right, add, or drop corrections to be passed back to the fire direction center as a normal adjustment mission correction. Either way, DeVeau states that a second round fire for effect was the norm. When asked if all students taught by the Etchey Training Group received this training concerning the conduct of CAS and calls for fire, he replied, "It is apart of the training syllabus!"
The problem of providing GPS coordinates in support of forward deployed troops is not a unique one for field artillery or infantry with Precision guided mortars. This is something that was addressed primarily for CAS when requirements for CAS through weather became a priority and LGBs could no longer be the sole providers of PG - CAS. This is how aircraft with the J series would be working with ground troops, and UAS operators .
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nam
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Re: Artillery Discussion Thread

Post by nam »

I can probably understand the need for a Precision Artillery in places like Afghanistan where US wants to have 24/7 CAS and keep the cost down.

Precision Artillery, rocket, propeller aircrafts are all towards that goal.

I am recalling the story by Col Rai in Kargil. He was out of ammo and Pakis was advancing towards his position. The spotter was on another peak. The advancing Pakis was plastered with something like 108 rounds at once. Nothing was left of the Pakis. It must have been some sight to watch 108 rounds land. Co Rai, got to tell the story, the Pakis didn't.

In scenarios like this, artillery units would know the accuracy issue and would probably fire rounds with various left/right/up/down combination to increase area of effect. Even if an artillery round has a CEP of 100m, other rounds would probably cover it up.

No one will fire a highly accurate single round in a mass battle. May be the videos you watch of impacts are done LOS, however every one I have seen has rounds covering impacts on wide area. Never 10-15 rounds falling in the same place.
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Re: Artillery Discussion Thread

Post by brar_w »

nam wrote:I can probably understand the need for a Precision Artillery in places like Afghanistan where US wants to have 24/7 CAS and keep the cost down.

Precision Artillery, rocket, propeller aircrafts are all towards that goal.

I am recalling the story by Col Rai in Kargil. He was out of ammo and Pakis was advancing towards his position. The spotter was on another peak. The advancing Pakis was plastered with something like 108 rounds at once. Nothing was left of the Pakis. It must have been some sight to watch 108 rounds land. Co Rai, got to tell the story, the Pakis didn't.

In scenarios like this, artillery units would know the accuracy issue and would probably fire rounds with various left/right/up/down combination to increase area of effect. Even if an artillery round has a CEP of 100m, other rounds would probably cover it up.

No one will fire a highly accurate single round in a mass battle. May be the videos you watch of impacts are done LOS, however every one I have seen has rounds covering impacts on wide area. Never 10-15 rounds falling in the same place.
Correct, these are assets that provide additional capability to field artillery units and are not a "one size fits all" solution, to be used indiscriminately regardless of the type of target and mission need. Even in Syria, USMC is seen having a mix of M1156 equipped, and conventional rounds and not all the rounds being fired were precision guided. The three classes allow you to dial your artillery support to the mission need as required.

https://www.youtube.com/watch?v=TuAuWnK5uF4

At the top of the page, there is an estimate on number of rounds required per target set. It is a good gauge of how precision support can aid in some environments, particularly when you require a large logistical trail to support troops deployed halfway across the world. Irrespective the deployed environment, anytime you can reduce the need to forward supply troops in terms of munition replenishment it is a good thing as it increases combat effectiveness and allows them to maneuver with a smaller footprint which usually translates to more agility.

Image
No one will fire a highly accurate single round in a mass battle.
I don't know what you mean by "mass battle" but if it is referring to providing area fires then yes, conventional artillery will be used to provide that effect on target. Precision artillery will continue to aid in missions that require more efficient support and into pinpoint strike where you cannot go in and pepper a large area with artillery strike.
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nam
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Re: Artillery Discussion Thread

Post by nam »

I hope they speed up ATAGS roll out. One of the side effects of upgrading ourself to medium artillery is on LOC.

So far we use 105 guns to respond to Pakis, which is deployed in large numbers. Once 155 replaces 105, IA would have no option other than open up with 155MM!

Right now we have the nonsense of 155 MM is escalation yada yada, need permission from spot boy in south block etc.

If Pakis survive for another 5 years and continue with their LOC acts, I would like to hear about how they feel, when 155 MM rains on them on a regular day CFV.

This might have been one of the reason for deliberately delaying IA medium artillery rollout. Must be one of those discreet CBM by the babus.
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Re: Artillery Discussion Thread

Post by vasu raya »

http://timesofindia.indiatimes.com/indi ... 448096.cms
Though Major Tango chose the best men for the job, one thing was bothering him - the de-induction or the return.

"That's where I knew I could lose guys," the book quotes him as recalling.

"Even the actual attack was not something that flustered the commandos. It was the return, an uphill trek to the LoC that was the truly daunting part."

"Their backs would be facing a blaze of fire from Pakistan Army posts, belatedly roused from their slumber. And the dominant position held by the posts would make the escaping warriors easy targets to spot and kill," the book says.
wouldn't artillery be used in these situations? the more the precision the better
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Re: Artillery Discussion Thread

Post by Gyan »

Re Shiv

Theoretical accuracy of howitzer is 0.5% of range and practical around 1%

Mortar 2% and 2-4%.

Now you can make estimate of how to hit a bunker at 25-35 km by howitzer and or 8km by mortar.

PGK fuse around 25-50m
Excalibur around 10-20m
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Re: Artillery Discussion Thread

Post by Gyan »

ramana wrote:
Gyan wrote:At US$ 100,000 a pop, an economic question arises, which is, why not use Guided MBRL? which is in the same price range but double the range and 5 times the bang. Therefore at present economic argument is made only by screw-in fins/gps.
Excuse me please stop and smell the roses. Who in India has the $100,000 artillery shells?
Why keep the continuous bs?
I think you have a tendency to fly off the handle without reading my posts or the thread. If you read the post it will be obvious that I am ALSO making the point that Excalibur type shells are too costly. Are you trying to replace Rohitvats nowadays?
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Re: Artillery Discussion Thread

Post by brar_w »

Gyan wrote:Re Shiv

Theoretical accuracy of howitzer is 0.5% of range and practical around 1%

Mortar 2% and 2-4%.

Now you can make estimate of how to hit a bunker at 25-35 km by howitzer and or 8km by mortar.

PGK fuse around 25-50m
Excalibur around 10-20m
As noted in the PGK's OT report, the demonstrated median CEP is much below the 30-50 m Objective and Threshold requirement. Same with Excalibur which as per the DOD's chief tester has demonstrated sub 10 m CEP as also noted in the test data cited by me earlier.

viewtopic.php?f=3&t=6651&start=3440#p2211344
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ramana
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Re: Artillery Discussion Thread

Post by ramana »

nam, In the newbie thread I posted links to youtube of a German analyst who looks at battles and wars. He concentrates on numbers to dispel myths and how wrong strategy is picked based on bias and improper assessment.

One take away is logistics since Napoleon's Russian campaign. Anything that reduces the trail or demand is good.

I agree IA wont use Excalibur type shells which cost an arm and a leg. But something that adds accuracy and shell safety is very much needed.

As borne out by the Dhanush trials and reports trickling in there have been numerous instances (including Bofors) of barrel burst, premature initiation. Both these are the shell functioning after fuze is armed.

Now the CEP of an M107 shell is about 260 m. This is acceptable for troops in the open and not for bunkers etc. Think of how many shells have to be fired to get any results. Unless accurate artillery fire is just a morale booster and good only for massed troops. I give two examples:
- Battle of El-Alamein. The 25 pounder gun was fired at German tanks in large numbers to break up tank assault. Later battle damage showed it didn't hit many tanks unless shell fragments hit the tank tracks or personnel with hatch open. The time fuze that fired the shell at a height was useful.
- Battle of Asal Uttar. I am still trying to get actual number of Pattons destroyed by artillery fire and not by tanks nor RCL. Turns out about 3 were damaged. Mind you 2000 shells from 25 pounder and 5.5 inch medium were fired and Maj. P.K. Jesus memoirs mention the quantum of fire but not the damage. The shelling did kill the Paki troops in the open.

155 mm is a great shell as the quantum of explosive is closer to the 5.5 inch medium gun of yesteryears and M107 on average costs quite low ~$400. The M592 fuze costs $50. But this combination needs a lot of shells to be fired. To take out a platoon in open it needs
43 rounds i.e. (43*450 = ~$20K) versus PGK. I agree the M107 with a proximity fuze (ECIL makes them) would be need much less shells.
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Re: Artillery Discussion Thread

Post by shiv »

Gyan wrote:Re Shiv

Theoretical accuracy of howitzer is 0.5% of range and practical around 1%

Mortar 2% and 2-4%.

Now you can make estimate of how to hit a bunker at 25-35 km by howitzer and or 8km by mortar.

PGK fuse around 25-50m
Excalibur around 10-20m
I saw a video of US soldiers shooting some of these smart rounds. It's a fairly long process of programming the round, cross checking the coords and firing. As brar pointed out - if the round finds itself outside the bounds of its coords it lands as a dud. The problem that I still see is accuracy of GPS - for Indian army. US mil GPS is for US mil. The other thing is secure comm from front line soldier to artillery gun. What does the US use?
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Re: Artillery Discussion Thread

Post by brar_w »

Shiv, fires support C2 is done through the Advanced Field Artillery Tactical Data System - AFATDS at all levels and across the Army and Marine Corps.

Here is a brief description of how the PGK is employed :
To fire a PGK-fuzed projectile, the unit Fire Direction Center (FDC) computes and transmits a digital firing solution to the howitzer section using AFATDS. The howitzer Section Chief then uses the DFCS on the firing platform to compute a PGK reference trajectory from the howitzer to the aimpoint. A cannoneer attaches the PGK with its protective canard cover to the projectile by hand and then tightens it using a PGK fuze wrench. The Enhanced Portable Inductive Artillery Fuze Setter (EPIAFS) sets the PGK by transferring the GPS key, fuze function mode, and reference trajectory data to the PGK. Once PGK is set, the canard cover is removed and the projectile is fired . When fired, PGK acquires a GPS signal and receives GPS data throughout the flight to update the projectile’s position. PGK then maneuvers the projectile along its reference trajectory toward its aimpoint. Should PGK fail to acquire a GPS signal or lose the signal during flight, PGK will not maneuver the projectile toward its aimpoint and the projectile will follow a ballistic trajectory to impact without detonation.
For additional information of how this is done in more complicated scenarios where the coordinates are being calculated through UAS employment, refer to my previous post that describes the process.

On the Excalibur the EPIAFS takes roughly 30 seconds to transfer the GPS data. I assume it would be a similar duration for the PGK.
The other thing is secure comm from front line soldier to artillery gun.
The security of the communication links would be required even for conventional artillery shells that are adjusted with the aid of forward observers. They would be either communicating target data or providing aids over the radio. This can be done here too.
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Re: Artillery Discussion Thread

Post by ramana »

Shiv, India will use GAGAN.

Hence the ARDE project for in house PGK type fuze.
What I find clever is the fixed canards which are more like forward vanes that add control authority to the shell via open feedback.
The GPS tracks and controls the vane spinning in the opposite direction to the shell spins direction. And power the whole whole thing while travelling to the target!

brar, Thanks works as I imagined. How is the trajectory corrected? Does the spin slow down or resume based on the trajectory to target?
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Re: Artillery Discussion Thread

Post by brar_w »

ramana wrote:
brar, Thanks works as I imagined. How is the trajectory corrected? Does the spin slow down or resume based on the trajectory to target?
The best understanding I have been able to develop is through this presentation. Haven't done a search to see if anyone in the US Army or ATK published research but will look for something to see if more details are available.
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Re: Artillery Discussion Thread

Post by Picklu »

It is 2D guidance, not 3D

My understanding is the lift generated gets altered due to the spin and any deviation in range gets corrected (within limits)

However the sidewise errors can't be.

But that's ok for the most part since based on currect dispersal pattern (there is one in Brar's ppt as well), range correct is required more
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Re: Artillery Discussion Thread

Post by Thakur_B »

Ramana, I cannot find any reference to ARDE's PGK type fuse for 155 mm shells, other than Dr. Avinash Chander's interview to bharat defence kavach from back in 2013. Can you redirect me towards any link ? Thanks.
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Re: Artillery Discussion Thread

Post by ramana »

ramana wrote:
ramana wrote:Kanson, ARDE and a group are working on Smart Fuzes like the US GPS Fuze and another. Will move away from mechanical fuzes is the goal.
In fact the pitch has same photo as the US GPS Fuze. Will link it on Saturday. Its on internet.

Link here:

http://ofb.gov.in/download/make_in_indi ... a_AMMN.pdf
Here hope they hurry up.

Looks like plan is to develop for 155mm guns and onwards.

Thakur

Look at pdf.
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Re: Artillery Discussion Thread

Post by ramana »

brar_w wrote:
ramana wrote:
brar, Thanks works as I imagined. How is the trajectory corrected? Does the spin slow down or resume based on the trajectory to target?
The best understanding I have been able to develop is through this presentation. Haven't done a search to see if anyone in the US Army or ATK published research but will look for something to see if more details are available.
Brar_W
Thanks. Slides 9,11, 12, & 13 make the compelling case for the PGK fuze.
The interesting thing is it works on 155mm, 105mm, and the mortars. Truly innovative dispersion reduction device,

Slide 9 defines the forces. I forgot the body lift which causes so many headaches. Wonder if there is coupling between the rotating canards and the fuze body. I still think you need to control how much de-spin you want.

Let me think on it.

BTW in the footnotes, the author explains why this won't work on fin stabilized rounds. The de-spin forces are additive to the body lift and counter productive.


I will try to locate the gripe from fuze vendors about so many features in one fuze which keeps them out. It's posted in the mil forum.

-----

OK found it in this thread only on Page 80

LINK

Essentially there is a plan to consolidate fuzes with ECIL and replace mechanical fuzes with electronic for tube artillery.
Note the CAG reports that M572 PD fuze has zero delivery.

I did not understand when I first read it.
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Re: Artillery Discussion Thread

Post by ramana »

A video that explains artillery usage in WWI which was the first artillery war



This video will focus on how the use of Artillery changed throughout the war and cover some of the many major innovations. Artillery tactics changed to a large degree from 1914 to 1918, whereas in 1914 the use of artillery in tactics and techniques had still a strong resemblance to the Napoleonic era, in 1918 the foundations of a modern artillery is clearly recognizable. Although the basic principles of indirect fire, massed fire, counterbattery fire, calibration and meteorological corrections and combined arms were known, they were usually not applied on the field in 1914, yet in 1918 these principles were used consistently and to a large degree by all sides.
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Re: Artillery Discussion Thread

Post by ramana »

The Dhanush has fired over 3000 rounds in the trials.
It would be good to know what is the approximate dispersion for the shells?
And what type of Fuzes were used so far : M572 fuze and the Proximity fuze?

Is it better than the 260m for the M107 shell?

The ARDE should develop their version of the PGK in two phases :
Phase I incorporate GPS and/INS to function the fuze in the vicinity of the target.
Phase II: Incorporate error correction with the rotating fins etc.

Phase I is suggested to give functionality to the Fuzes.
Dhanush dispersion with all its modern computer should be better than the Bofors gun.
The proximity fuze already has a battery section.
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Re: Artillery Discussion Thread

Post by Kanson »

^ Don't have numbers on dispersion, but Danush is established as more consistent. Consistency is proved beyond doubt. Fired over 4000 rounds in trials, another first, and a record in terms of trials held so far.

Regarding PGK, IA is listening/talking to various players including european, non-american entities. Gives the impression they too want such solution.
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Re: Artillery Discussion Thread

Post by Indranil »

This PGK solution is absolutely great. Its simplicity is its elegance. I expect every country to field their version shortly.
ramana
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Re: Artillery Discussion Thread

Post by ramana »

Indranil Its great for US allies as it relies on GPS.

The Indian version will have two other enhancements: Gagan and INS.
As the range is less than 50 km the INS will give good results.
As you are aero type, tell me how they control the de-spin process to shape the trajectory?

I am thinking the coil acts as a regenerative brake and controls the de-spin rate of the canard

The ATK presentation says shell aerodynamics is complex but once understood the concept is simple.
nam
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Re: Artillery Discussion Thread

Post by nam »

Wonder if rockets(MBRL) can be fitted with the PGK. Would make a deadly precision weapon,cheap and larger warhead.
Last edited by nam on 12 Sep 2017 01:30, edited 1 time in total.
ramana
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Re: Artillery Discussion Thread

Post by ramana »

nam wrote:Wonder if rockets(MBRL) can be fitted with the PGK. Would make a deadly precision weapon and cheap.
Yes. US wants to use PGK on mortars to GMLRs.
The caveat is the projectile should be spin stabilized.
The reason is the canard lift is additive to the body lift for fin stabilized bodies.
In plain language wont work for fin stabilized rockets.

I will post some links in a few minutes.
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Re: Artillery Discussion Thread

Post by Bart S »

nam wrote:Wonder if rockets(MBRL) can be fitted with the PGK. Would make a deadly precision weapon,cheap and larger warhead.
Well, there is already stuff like the Israeli TCS and APKWS for smaller rockets so its certainly doable.
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Re: Artillery Discussion Thread

Post by ramana »

PGK Links:

1) PGK Pitch from ATK 2008 ATK Pitch
Gives a very good cost benefit summary of using a precision guidance on artillery shells and they system wide benefits

2) Aerodynamics of PGK shell LINK

This one is study by a South Korean University. Only the abstract.

3)Aerodynamics of course corrected spin stabilized shells

This one is a lab study by Bofors and has two additional bells and whistles.
Indranil
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Re: Artillery Discussion Thread

Post by Indranil »

Ramana sir, slides 7 and 8 in the slide deck posted by brar answers it.

By placing the control canards at the correct orientation (in the plane perpendicular to the longitudinal axis of the projectile), you can change the net lift on the projectile. As the CL is in front of the CG, this creates the moment. The stepper function is achieved using adaptive braking using a simple alternator.
Picklu wrote:It is 2D guidance, not 3D

My understanding is the lift generated gets altered due to the spin and any deviation in range gets corrected (within limits)

However the sidewise errors can't be.

But that's ok for the most part since based on currect dispersal pattern (there is one in Brar's ppt as well), range correct is required more
Incorrect sir, the nose can be moved "left, right, top, bottom". That is the 2D guidance.
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Re: Artillery Discussion Thread

Post by Kakarat »

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