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PostPosted: 11 Apr 2012 03:36 
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MEMS based accelerometers and gyros (that I am aware of) available today have too much 'drift' to be useful over the long durations that are needed for 3500km/~15 minute flight range. What MEMS sensors can be useful for, is providing robustness against jamming over a shorter duration of time. RLGs are much more accurate, but also heavier.


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PostPosted: 11 Apr 2012 03:53 
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Wondering if GAGAN can do laser satellite communication. I am sure the khaans are way up there with this. This can prevent jammming too. of course, protecting the satellite is another aspect, and reducing the bandwidth, with LPI burst mode communication could correct signals with jamming.

Re/something on the lines of AESA:[German satellite TerraSAR-X and US satellite NFIRE] / though


Last edited by SaiK on 11 Apr 2012 03:55, edited 1 time in total.

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PostPosted: 11 Apr 2012 03:55 
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Sudeep
True. That's why they are in the back-up device to the more accurate RLG, with Glonass update possible. Doubtful any device can jam an ICBM from receiving Glonass update?


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PostPosted: 11 Apr 2012 06:38 
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An ICBM is yet to be launched in anger. For a weapon invented 40 years or so ago, thats an impressive record. If it comes to ICBMs being launched in anger, its almost a given that Satellite Navigation systems will also be attacked (regardless of any treaties), or access to those signals can be selectively denied over theaters and regions based on the then interests of the nations that control that SatNav system.

It will be a blunder for your doomsday capability to rest on technologies and platforms that you dont fully control. Without a common war fighting treaty, without common identified enemies and friends, without common interests, and without a symmetry in the relationship that goes beyond "Ill buy your weapons" - how can you rest your most critical, most potent weapon on RF that another country transmits? You can buy yourself some warm fuzzy feeling by saying, OK - Ill rely on both GPS and Glonass.. both cant be denied at the same time.. right? going further along the same logic, even China is launching a SatNav constellation, called Compass/Beidou. They have even launched a few Satellites, they are further along than Galileo. Why not integrate Beidou RF into MINGs? Its laughable...

IMO, for strategic weapons, there is no alternative to high accuracy INS systems, (which Angi 4 has, with its RLGs). Everything else, you will achieve 40 meters accuracy in tests, but who knows how much when its really needed.


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PostPosted: 11 Apr 2012 07:06 
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as I mentioned earlier, khan has used GPS in icbm tests but does not rely on it in a real war. they have dual INS and star sensor pkg and thats it.
star sensor pkg probably got its first breakthrough for deep space probes. we need to implement it if not already...said to correct minor drift in the INS.


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PostPosted: 11 Apr 2012 07:33 
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ms Pulsars can be used for navigation.. but I am not sure if the electronics for these can be shrunk to small size required. At least, no one will have the technology to take those down with out alien deathstars :-D


http://www.sbir.nasa.gov/SBIR/abstracts ... -9013.html
Quote:
The primary non-NASA XNAV applications would be to provide primary or secondary navigation services for DoD missions. For MEO, GEO, HEO, and even cis-lunar missions where GPS has limited availability, XNAV can provide primary autonomous navigation capability. In addition, XNAV could provide an essential backup navigation capability for missions which normally rely on GPS but have a need for continuity of operations in the event of loss or denial of GPS. These applications are being actively studied through DARPA's XNAV program, and the Microcosm team has strong ties to that program.


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PostPosted: 11 Apr 2012 18:01 
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Another round of Nag trials in June-July


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PostPosted: 11 Apr 2012 21:07 
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lock on (infrared) before launch sounds very interesting.. it would be really interesting to find infra jammers for 7km range walas. is there one?


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PostPosted: 11 Apr 2012 22:23 
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^ something like a moving target with BAE Adaptiv tiles could create difficulties.

Unless I missed out something.


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PostPosted: 11 Apr 2012 22:37 
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SaiK wrote:
lock on (infrared) before launch sounds very interesting.. it would be really interesting to find infra jammers for 7km range walas. is there one?


In this case it has to be an Imaging Infra red jammer.


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PostPosted: 11 Apr 2012 22:47 
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they should test out of a few of these nags at night during new moon days.

nags out during new moon midnight sounds scary enough


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PostPosted: 11 Apr 2012 23:14 
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There are no countermeasures to Imaging Infra Red seekers. They are immune to any kind of jamming.


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PostPosted: 11 Apr 2012 23:19 
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^^^ DIRCM


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PostPosted: 12 Apr 2012 01:16 
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^^ DIRCM uses arc lamp or lasers to flash a high intensity beam and dazzle conventional IR seeker. It doesnt work against IIR that gets a heat image like this http://www.ausairpower.net/000-AIM-9X-F ... -300-S.jpg It analyses the target image, and rejects any dazzling.

This is why IIR is unbeatable today.


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PostPosted: 12 Apr 2012 01:46 
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High powered, laser based DIRCM is being evolved further to handle IIR seekers as well.

Page 16, USN S&T Development plan

IIR seekers: A laser based DIRCM and kinematic flares to defeat I2R (IIR) seekers for FY13.

http://www.paxpartnership.org/Knowledge ... tation.pdf

The ex Soviet Union used to be a leader in laser tech. It will be interesting to see what DIRCM the FGFA/PAKFA has & the threats it can handle.


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PostPosted: 12 Apr 2012 07:29 
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Can Brahmos have its control surfaces folded?
http://img826.imageshack.us/img826/7093 ... o20122.jpg
http://www.militaryphotos.net/forums/showthread.php?210753-Defexpo-India-2012/page20


Last edited by Gerard on 15 Apr 2012 04:33, edited 1 time in total.
removed inlining


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PostPosted: 12 Apr 2012 09:32 
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The answer to that is yes. look closely.
http://4.bp.blogspot.com/-ZRiSC9hp1gE/T ... 770494.JPG


Last edited by Gerard on 15 Apr 2012 04:33, edited 1 time in total.
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PostPosted: 12 Apr 2012 13:09 
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Crucial tests of three Agni missiles soon
http://ibnlive.in.com/news/crucial-test ... 0-117.html
Quote:
Preparations are on at the Wheelers Island off the Odisha coast for a series of tests of three Agni missiles, including the maiden test of India’s longest-range ballistic missile Agni-5. They will be held shortly. Prior to the first development trial of 5,000-km range Agni-5, the DRDO has planned to conduct two user trials of 700-km range Agni-1 and 2,000-km range Agni-2 missile.
As India is attempting its first intercontinental missile test, scientists are leaving no stone unturned for a successful mission. A defence official said the three missiles would require three separate range configurations.
Hence, they would be test-fired on three occasions between April 18 and April 25.


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PostPosted: 16 Apr 2012 03:05 
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FIRST GLIMPSE OF AGNI V ON LAUNCHPAD IN THE LINK BELOW: (NO VENTED INTERSTAGE) :twisted:

Quote:
TRIBUNE EXCLUSIVE
India’s most potent missile Agni V all set for launch
By Raj Chengappa

SNEAK PEAK: Agni V being readied for launch at Wheeler Island

In the remote Wheeler Island off the Odisha coast, the countdown has begun for the first test of India's most sophisticated and powerful ballistic missile ever built, Agni V.

If all goes well, the Defence Research and Development Organisation (DRDO) which built the missile, is expected to launch Agni V on Wednesday, April 18, from the Island.

With a planned range of 5,000 km, the Agni V will traverse 2,000 km more than any Indian missile has ever done. Wednesday's launch will see the missile first power its way to a vertical height of 500 km in the atmosphere before following a ballistic trajectory that will see it splash down in the Indian Ocean way beyond Indonesia.

A commercial jetliner would take over six hours to traverse such a distance. But Agni V, travelling at 24 times the speed of sound and 30 times faster than a commercial jet, will traverse that distance in just 18 to 20 minutes. In doing so, it will become not just the longest range ballistic missile in India's strategic armoury but also its fastest. Most importantly, Agni V would put most of China's major cities, including Beijing and Shanghai, within Indian missile range.

Speaking exclusively to The Tribune, Vijay Kumar Saraswat, DRDO Chief and Scientific Adviser to the Union Defence Minister, said, "In terms of performance, Agni V is the ultimate step for India in terms of ballistic missile technology. It is pushing at the outer limits of the Intermediate Range Ballistic Missile (IRBM) class."

What Saraswat is unwilling to explicitly state, is that a successful test of Agni V would give India the capability of building long-range Intercontinental Ballistic Missiles, ICBMs or missiles that can reach targets of 8,000 km or more. (Meaning its probably got a range of 8,000 km depending on the payload)

With a warhead weight of 1,500 kg (1.5 tonne) Agni V will ultimately be capable of carrying multiple nuclear warheads giving it deadly strike capability. :twisted:

Agni V would be a significant step up from the range of Agni missiles that India currently has in its armoury. Agni I goes to 700 km and Agni II, 2000 km. Both these are primarily meant to target Pakistan, giving India a capability to strike its neighbour from any part of the country.

Agni III and Agni IV are missiles in the 3,000 km class meant for China and other regional neighbours. The distance though is a limitation as these classes of missiles would be unable to strike many of China's strategic cities or locations. So the need for Agni V.

Speaking exclusively to The Tribune from the Wheeler Island, where final tests are being done for Agni V, Avinash Chander, DRDO's Chief Controller R&D (Missiles and Strategic Systems), said, "There are many firsts we are incorporating in Agni V, these include two all new composite motors that would propel the missile to distances bordering ICBM capabilities."

At 17 metres in height, Agni V is almost 5 stories tall and has a diameter of two meters - similar to that of the giant main sewage pipelines that are laid in most Indian cities. Agni V is short and squat as compared to India's space rockets.

Almost three years in the making, Agni V is a three-stage rocket that, Chander says, has one of the most highly developed guidance systems that the DRDO has ever built to enable it to strike targets at great distance with stunning accuracy.
:mrgreen:

While the first stage motor is similar to the one used in Agni III, the second and third stage motors are brand new and built of light composite materials that are being flight tested for the first time. "It reduces weight and gives the missile greater punch,'' says Chander.

Though the first launch would be from a static harness at the Island, Agni V would have tremendous road mobility once it is fully developed. These include a canister launch which means that it gives India "stop and launch" capability from any part of the country. 8) "Once we successfully test Agni V we would have broken the barrier of long range ballistic missile systems,'' says Saraswat.



Missile Muscle

n With a range of 5,000 km, Agni V will traverse 2,000 km more than any other Indian missile

n Travelling at 24 times the speed of sound, Agni V will traverse 5,000 km in just 20 minutes

n If successful, it will give India the capability of striking all major Chinese cities, including Shanghai

n The technology being used in Agni V will ultimately give India the capability to build Inter-Continental Ballisitic Missiles (ICBMs)


Image

http://www.tribuneindia.com/2012/20120416/main2.htm


Last edited by RoyG on 16 Apr 2012 06:48, edited 1 time in total.

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PostPosted: 16 Apr 2012 05:56 
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RoyG, Some quick points:
- There are interstages between the first an second and second and third stages. Its just below the band where the TEL holds the vehicle.
- No truss structure between the F/S and S/S. Means they have mastered the timing issue between separation and SS motor ignition i.e the bottle type igniter is being use for reliability. So no need for the vented structure.
-Most likely the separation is by shaped charge and not MDF type cutting charge.
- Third stage is a frustrum of a cone!
- The payload is a unitary one like in AIII and not a bus with MIRVs yet.

I haven't seen conical motors except on the Sprint ABM which made it go hypersonic in just a few secs. The conical motor has static stability and needs much less control margin.

So the T/S and RV section are traveling at very high speed but still in atmosphere.


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PostPosted: 16 Apr 2012 06:48 
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Ramana,

Thanks for pointing out the error. I meant vented interstage. WRT the conical motor, is it possible that the unitary warhead could be a hypersonic skipper to evade ABM defenses? It def has the range to pull it off. I'm thinking it could be a derivative of the agni IV warhead.


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PostPosted: 16 Apr 2012 07:07 
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Mach24 is good - matches the best out there.
I was hoping for a cansister launch from day1, it is a must for true road mobility.
could be a while before we get to FOC with cansister - perhaps around 5 yrs.

for MIRV, the conical motor will need to be cylindrical again to support the ogival nosecone. indicates it will be A5-mk2 later. I was hoping that would go that route from day1.


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PostPosted: 16 Apr 2012 07:11 
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http://www.eurasiareview.com/10042012-what-missiles-are-threatening-europe-analysis/


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PostPosted: 16 Apr 2012 09:22 
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Agni-5 looks good , no interstage , nice clean missile perfect for wooden round.


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PostPosted: 16 Apr 2012 09:59 
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No Vented interstage.

You need an interstage to connect the motors.

No other way.

Look up "Design of Missile Structures" E. Bruhn. dated book but still very essential.
The materials have changed from Al based alloys to composites with their own issues.


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PostPosted: 16 Apr 2012 10:32 
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ramana wrote:
No Vented interstage.

You need an interstage to connect the motors.

No other way.


Yes i mean Vented Interstage , they would probably use some kind of rocket motors to prevent interia during stage separation hitting each other , while vented inter-stage may not be of great use for ground launched missile , this approach will be very useful when they design bigger slbm to be fitted on confined spaces of future ATV with its own premium on space.

Quote:
The materials have changed from Al based alloys to composites with their own issues.


That being true but the benefit of getting payload vs range advantage is best served using composite stage , all stage composite motor has been in use for long time with Soviet first deploying all 3 stage composite motor with SS-25 in early 80's


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PostPosted: 16 Apr 2012 10:36 
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Looking at the TEL size both Agni 3 and Agni 5 seems to have same height!

"If" that is true then scientists were able to increase range within same dimensions or Agni 3 had "similar" range as Agni 5 from the beginning?

ImageImage


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PostPosted: 16 Apr 2012 10:37 
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There is something called range partials. ie delta range for delta weight increase. The most range partials is for the upper stages. IOW the lighter the upper stages the higher is the range gain. What this means is one can use Al interstage between the SS and FS as that would be quite economical.


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PostPosted: 16 Apr 2012 10:40 
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the vented interstage length has been used for the conical section keeping length about same.
also to me, the blue cone looks smaller relative to black cone in both length and width-at-base.

Austin, unfortunately it looks like Russia is not willing to txfer their composite casing tech for the 1st stage...thats the biggest challenge.

the fat 1st and 2nd stage with tapering cone shape from there gives it the look more of a ABM interceptor than a ICBM.
http://www.aipac.org/NearEastReport/ima ... -Med-2.jpg


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PostPosted: 16 Apr 2012 10:50 
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GD, There is a taper from the top to bottom. The SS will be slightly smaller in dia than FS and so and so forth.

It prevents missile bow. Eg like a flying banana.


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PostPosted: 16 Apr 2012 11:09 
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Singha wrote:
also to me, the blue cone looks smaller relative to black cone in both length and width-at-base.


The size and resolution of picture when comparing might play a trick there


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PostPosted: 16 Apr 2012 11:09 
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mach24 is true ICBM territory....the topols and tridentD5 of the world. whatever fig leaf of this being a meek IRBM++ gets blown off by that statement alone.


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PostPosted: 16 Apr 2012 11:18 
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Also nice to see Raj Chengappa's name beside the article. Haven't seen much of him since his acclaimed "Weapons of peace". A real bright spot, together with T.S Subramaniam of Frontline, on Indian defense reporting. Very uplifting and richly detailed, so different from the sour, negative stuff from the pens of Sawhney, Thapar, Bedi et al.


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PostPosted: 16 Apr 2012 11:24 
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Quote:
mach24 is true ICBM territory....the topols and tridentD5 of the world. whatever fig leaf of this being a meek IRBM++ gets blown off by that statement alone.



Quite. but how does that sit with the 500 km apogee. :twisted:


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PostPosted: 16 Apr 2012 11:28 
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I guess some of the US satellites and dedicated assets like Cobra Ball would monitor the test and try to suck in as much as telemetry data as possible and that of RV.

There was a report in AW&ST some time back that was detailing some history of cobra ball , it mentioned every time india tested its BM ,cobra ball would find its way in bay of bengal.


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PostPosted: 16 Apr 2012 11:37 
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ramana wrote:
The payload is a unitary one like in AIII and not a bus with MIRVs yet.

Can you explain this saab.


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PostPosted: 16 Apr 2012 11:48 
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D Roy wrote:
Quote:
mach24 is true ICBM territory....the topols and tridentD5 of the world. whatever fig leaf of this being a meek IRBM++ gets blown off by that statement alone.

Quite. but how does that sit with the 500 km apogee. :twisted:

To add, how does it compare with the 900 km apogee achieved by a 3000 to 3500 km ranged Agni-IV?


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PostPosted: 16 Apr 2012 11:56 
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Bus is similar to the multi satellite launch during civilian sat launch

Each unit will be launched in a serial manner once the desired space location is reached


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PostPosted: 16 Apr 2012 12:04 
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Folks is there any news on Nirbhay launch, supposed to be tested in the middle of this month?


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PostPosted: 16 Apr 2012 12:17 
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Wow sounds like it was launched in a depressed trajectory.


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