Nirbhay cruise missile to be tested by next month finally

[Bratva]

It depends strictly on the user what method they want to use for a particular purpose.In this case Pakistan has chosen DSMAC,India chose to use SAR seekers.
Yes these are RF SAR seekers and not the kind of regular RF seekers used in Anti ship cruise missiles.I hope you know what SAR means.But still let me explain the rational behind this.
You see,in DSMAC,you feed the missile's guidance computer with pre reckoned images of the target and the an onboard camera on the missile takes images of the target and the guidance computer then correlates the pictures with the prefed images.
Now Nirbhay LACM also uses a similar technique that it correlates SAR imagery with the prefed target images.Only difference is,in older DSMAC method you use a camera......instead in this case we use a SAR seeker.
A SAR seeker has several key advantages over a camera like for example:
1.The efficacy of a camera or any other optical sensor is significantly degraded in cloudy or adverse weather but weather has got very little effect on SAR.
2.A camera can be fooled by using smoke,aerosaul or optical camouflage systems,but a SAR can not be fooled that way.

So you see,it's not something to laugh at.Just because you do not use it or (rather can't given the fact that Pakistan still can not develop radars or seekers on its own) doesn't mean it's a bad idea or it can not be made to work out successfully.

Several Indian companies like Datapatterns and VEM Electronics in collaboration with the LRDE has developed a range of SAR seekers for Prithvi 3,Prahaar and Shaurya NLOS BSMs,Brahmos 1 LACM variants and subsonic cruise missiles.

I was surprised because, if you are putting active seeker in LACM, it means you have the ability to go after moving targets as well. Officially, did GoI or DRDO said they are using active seeker in Nirbhay or is it speculations from Blogs yet?

Every LACM up to this day used the hierarchical approach. First they build a LACM which go after static targets, then they build active seekers. Likewise, Tomahawk block IV last year attained the active seeker and capability to go after moving targets.

Active seeker in Brahmos makes sense. But I was surprised, on it's first maiden flight, they are putting active seeker in LACM. Perhaps that was the cause of failure because DRDO was too ambitious?

 

[Omega007]

Similarly to this particular query Mr Prasun gave this particular reply ...quite informative !

" None of the world’s long-range cruise missiles use IR seekers. They all use RF sensors that making use of DSMAC techniques. Even the BrahMos uses such RF sensors & DSMAC techniques for inertial navigation & terminal homing"



" Optical co-relation & scene matching technique is used ONLY by man-in-the-loop guidance systems of the type used by PGMs like Taurus KEPD-350, Delilah, Popeye, Spice, etc. Here, a two-way data-link transmits the image of the target constantly to the launch-aircraft’s pilot, which means that the missiles are NOT autonomous but are guided all through their flight profile by human intervention. Cruise missiles like Nirbhay, CJ-10, TLAM, Babur, etc on the other hand make use of active on-board RF sensors—SAR seeker—for terrain profiling & then using the scene-matching technique by comparing the profile of the scanned image with those that are stored in the cruise missile’s on-board mission computer (these images being obtained earlier by SAR sensors mounted on various recce platforms). That’s why on TLAMs there’s always an avionics LRM called DSMAC illuminator, i.e. an active RF sensor. In this arena, the Soviets were the technological pioneers. DSAMAC illuminator is by no means an optronic sensor as many would like to believe or assume.
1-metre accuracy has never been attained to date by any autonomous cruise missile, but only by those man-in-the-loop tactical PGMs making use of IR sensors & two-way data-links. Even the BrahMos-1 has 3-metre accuracy thanks to its on-board SAR seeker making use of DSMAC technique. For nuclear-armed Nirbhay, even a 100-metre accuracy is excellent, given the fact that its nuclear warhead will be highly destructive. "

Contrary to what many believe,Prasun is actually a very knowledgeable person with a no-nonsense attitude.But with all due respect to him,he made some factual errors while writing this comment.
Like he says optical scene correlation is used only by those man-in-the-loop pgms like Delilah or Taurus but it's the half truth only.

You see,the man in the loop pgms do make use of this but they are not the only ones.Even LACMs with complete autonomous guidance system make use of optical DSMAC sensors.You see,there is simply no proof that LACMs like CJ 10,YJ 82 or Babur uses SAR RF seekers for DSMAC,in reality all the above mentioned LACMs make use of onboard cameras mounted on the lower fuselage for DSMAC scene correlation.
From reading his comments,it seems like he got the radar altimeter used in majority of LACMs (like Babur,YJ 82,Tomahawk etc) for their TERCOM confused with a SAR based DSMAC.The problem with radar altimeter is that it can be easily picked up by passive radar finger printing systems like India's Divya dristi or the Vera E which has been widely deployed by now by many countries.That is why both the Indian Armed Forces and DRDO has planned to replace them with laser altimeters in all the cruise missiles.

So let me clear the confusion for you.Here is the thing,the LACMs like Babur,Cj 10,Tomahawk etc make use of RF sensor namely radar altimeter for TERCOM but NOT DSMAC.They use optical sensors of some form for DSMAC purpose.
On the other hand,LACM version of Brahmos,Nirbhay and the under development supersonic ALCM (also known as Air Delivered Munition or ADM) are among the pioneer missiles that would make use of laser altimeter - RLG-INS - GPS combo for TERCOM and Radio Frequency SAR seekers for DSMAC purposes.I hope now it's clear for you.

Besides,Brahmos Block 2 did achieve 1 meter CEP,atleast the anti ship version did.It's been posted on youtube and seeing is believing.....don't you think??

 

[Indo-guy]

Contrary to what many believe,Prasun is actually a very knowledgeable person with a no-nonsense attitude.But with all due respect to him,he made some factual errors while writing this comment.
Like he says optical scene correlation is used only by those man-in-the-loop pgms like Delilah or Taurus but it's the half truth only.

You see,the man in the loop pgms do make use of this but they are not the only ones.Even LACMs with complete autonomous guidance system make use of optical DSMAC sensors.You see,there is simply no proof that LACMs like CJ 10,YJ 82 or Babur uses SAR RF seekers for DSMAC,in reality all the above mentioned LACMs make use of onboard cameras mounted on the lower fuselage for DSMAC scene correlation.
From reading his comments,it seems like he got the radar altimeter used in majority of LACMs (like Babur,YJ 82,Tomahawk etc) for their TERCOM with a SAR based DSMAC.The problem with radar altimeter is that it can be easily picked up by passive radar finger printing systems like India's Divya dristi or the Vera E which has been widely deployed by now by many countries.That is why both the Indian Armed Forces and DRDO has planned to replace them with laser altimeters in all the cruise missiles.

So let me clear the confusion for you.Here is the thing,the LACMs like Babur,Cj 10,Tomahawk etc make use of RF sensor namely radar altimeter for TERCOM but NOT DSMAC.They use optical sensors of some form for DSMAC purpose.
On the other hand,LACM version of Brahmos,Nirbhay and the under development supersonic ALCM (also known as Air Delivered Munition or ADM) are among the pioneer missiles that would make use of laser altimeter - RLG-INS - GPS combo for TERCOM and Radio Frequency SAR seekers for DSMAC purposes.I hope now it's clear for you.

Besides,Brahmos Block 2 did achieve 1 meter CEP,atleast the anti ship version did.It's been posted on youtube and seeing is believing.....don't you think??

Agree Mr Prasun is an extremely knowledgeable guy ....

and also that he too can make mistakes at times ...although most of the times he tends to be correct !

Thanks once again for clearing so many things ...

Yes I saw brahmos videos ... one can be very certain about it's CEP given the accuracy with which it hit its target in those videos ....

Contrary to what many believe,Prasun is actually a very knowledgeable person with a no-nonsense attitude.But with all due respect to him,he made some factual errors while writing this comment.
Like he says optical scene correlation is used only by those man-in-the-loop pgms like Delilah or Taurus but it's the half truth only.

You see,the man in the loop pgms do make use of this but they are not the only ones.Even LACMs with complete autonomous guidance system make use of optical DSMAC sensors.You see,there is simply no proof that LACMs like CJ 10,YJ 82 or Babur uses SAR RF seekers for DSMAC,in reality all the above mentioned LACMs make use of onboard cameras mounted on the lower fuselage for DSMAC scene correlation.
From reading his comments,it seems like he got the radar altimeter used in majority of LACMs (like Babur,YJ 82,Tomahawk etc) for their TERCOM with a SAR based DSMAC.The problem with radar altimeter is that it can be easily picked up by passive radar finger printing systems like India's Divya dristi or the Vera E which has been widely deployed by now by many countries.That is why both the Indian Armed Forces and DRDO has planned to replace them with laser altimeters in all the cruise missiles.

So let me clear the confusion for you.Here is the thing,the LACMs like Babur,Cj 10,Tomahawk etc make use of RF sensor namely radar altimeter for TERCOM but NOT DSMAC.They use optical sensors of some form for DSMAC purpose.
On the other hand,LACM version of Brahmos,Nirbhay and the under development supersonic ALCM (also known as Air Delivered Munition or ADM) are among the pioneer missiles that would make use of laser altimeter - RLG-INS - GPS combo for TERCOM and Radio Frequency SAR seekers for DSMAC purposes.I hope now it's clear for you.

Besides,Brahmos Block 2 did achieve 1 meter CEP,atleast the anti ship version did.It's been posted on youtube and seeing is believing.....don't you think??

There were some queries on his blog as to why India is using monopulse X band SAR which no other countries seem to be using for similarly ranged cruise missile ....
He couldn't give satisfactory answer .

He quoted example of some Russian missile with range of 60 km using similar X band SAR

Do you have any info as to why India is using this monopulse X band SAR in Nirbhay ?

 

[Omega007]

I was surprised because, if you are putting active seeker in LACM, it means you have the ability to go after moving targets as well. Officially, did GoI or DRDO said they are using active seeker in Nirbhay or is it speculations from Blogs yet?

Every LACM up to this day used the hierarchical approach. First they build a LACM which go after static targets, then they build active seekers. Likewise, Tomahawk block IV last year attained the active seeker and capability to go after moving targets.

Active seeker in Brahmos makes sense. But I was surprised, on it's first maiden flight, they are putting active seeker in LACM. Perhaps that was the cause of failure because DRDO was too ambitious?

Oh in that case I'm extremely SORRY and I apologise to you from my heart.

Coming to your post,although GoI and DRDO is yet to make any comment on the nature of terminal guidance mechanisms to go onboard Nirbhay LACM,but available information directs us to believe that it's gonna be SAR seeker.
Why?You see,in Defexpo 2014,the only optical seeker that was displayed was the passive imaging infrared sight for Nag ATGM,there was no other optical seeker on the display.But there were atleast two SAR seekers shown in that event.One by Datapatterns and the other being of VEM Electronics and there were brief infos about the seekers which reveals that the Datapatterns one is to replace the original Russian seeker from Agat for Brahmos LACM variant and the VEM Electronic one for Nirbhay.
So as you can see,although it hasn't been officially disclosed by DRDO or GoI yet,but it's pretty much known secret by now.
WRT to the failure of the first test flight,it couldn't have been due to faulty SAR seeker because the SAR seeker is there for DSMAC terminal guidance purpose.But the missile had deviated from its pre-planned waypoints after flying only about 300 km,so it can not have been due to faulty SAR seeker.Most probably the Ring Laser Gyro had malfunctioned.

And yeah,it does sound like a bit over ambitious but you have to also take it into account that DRDO has started much much later in the subsonic LACM race than other countries there is simply no time left for applying the universal crawl - walk - run - sprint - jump approach and they had no other option but to straight go for the "jump".It's been already too late and it's now make or break situation for us.

 

[Omega007]

Agree Mr Prasun is an extremely knowledgeable guy ....

and also that he too can make mistakes at times ...although most of the times he tends to be correct !

Thanks once again for clearing so many things ...

Yes I saw brahmos videos ... one can be very certain about it's CEP given the accuracy with which it hit its target in those videos ....



There were some queries on his blog as to why India is using monopulse X band SAR which no other countries seem to be using for similarly ranged cruise missile ....
He couldn't give satisfactory answer .

He quoted example of some Russian missile with range of 60 km using similar X band SAR

Do you have any info as to why India is using this monopulse X band SAR in Nirbhay ?[/quiet]


Look bro,it's almost certain that Nirbhay is gonna make use of a X band frequency agile SAR seeker as its DSMAC illumination device for terminal guidance.But WHY??One could only speculate for the time being.I've already posted my opinion in this thread in response to @mafiya.
I'm posting my opinion again.But this is just my speculation and shouldn't be taken as Gospel.

Ok,LACMs use DSMAC technique for terminal guidance.Now as you know by now,DSMAC is a technique and not a hardware.In layman's terms,it means matching prefed images in its mission computer with the image taken by the missile or scene-correlation to explain it in a single word.
Now one could either use some sort of optical device or a SAR seeker onboard the LACM for taking the images of target.In SAR imaging,one uses the radar waves to take spatial images of an objective or in other words,SAR means using the radar like a video camera.

Now SAR has got several advantages over regular optical sensors.For example,
1.Optical seekers' efficacy is significantly affected by cloudy weather but SAR can very easily work almost perfectly in bad weather without any significant degradation in performance.

2.Optical seekers can be fooled more easily by applying smoke,special aerosauls or optical camouflage.But SAR seekers can not be fooled that easily.
These are to name a few.There could be other reasons too which I may not be aware of.

Hope I could help you.

Oh and by the way,very recently the Americans. have started to use SAR seekers in their latest model IV Tomahawk LACM.

@Indo-guy
Look bro,it's almost certain that Nirbhay is gonna make use of a X band frequency agile SAR seeker as its DSMAC illumination device for terminal guidance.But WHY??One could only speculate for the time being.I've already posted my opinion in this thread in response to @mafiya.
I'm posting my opinion again.But this is just speculation.

Ok,LACMs use DSMAC technique for terminal guidance.Now as you know by now,DSMAC is a technique and not a hardware.In layman terms,it means matching prefed images in its mission computer with the image taken by the missile on scene-correlation in a single word.
Now one could either use some sort of optical device or a SAR seeker onboard the LACM for taking the images.In SAR imaging,one uses the radar waves to take spatial images of an objective or in other words,SAR means using the radar like a video camera.

Now SAR has got several advantages over regular optical sensors.For example,
1.Optical seekers' efficacy is significant in cloudy weather but SAR can very easily work perfectly in bad weather without any significant degradation in performance.

2.Optical seekers can be fooled more easily by applying smoke,special aerosauls or optical camouflage.But SAR seekers can not be fooled that easily.
These are to name a few.There could be other reasons too which I may not be aware of.

Hope I could help you.

Oh and by the way,very recently the Americans. have started to use SAR seekers in their latest model IV Tomahawk LACM.
If you don't mind,what's your facebook id??

 

[Indo-guy]

@Indo-guy
Look bro,it's almost certain that Nirbhay is gonna make use of a X band frequency agile SAR seeker as its DSMAC illumination device for terminal guidance.But WHY??One could only speculate for the time being.I've already posted my opinion in this thread in response to @mafiya.
I'm posting my opinion again.But this is just speculation.

Ok,LACMs use DSMAC technique for terminal guidance.Now as you know by now,DSMAC is a technique and not a hardware.In layman terms,it means matching prefed images in its mission computer with the image taken by the missile on scene-correlation in a single word.
Now one could either use some sort of optical device or a SAR seeker onboard the LACM for taking the images.In SAR imaging,one uses the radar waves to take spatial images of an objective or in other words,SAR means using the radar like a video camera.

Now SAR has got several advantages over regular optical sensors.For example,
1.Optical seekers' efficacy is significant in cloudy weather but SAR can very easily work perfectly in bad weather without any significant degradation in performance.

2.Optical seekers can be fooled more easily by applying smoke,special aerosauls or optical camouflage.But SAR seekers can not be fooled that easily.
These are to name a few.There could be other reasons too which I may not be aware of.

Hope I could help you.

Oh and by the way,very recently the Americans. have started to use SAR seekers in their latest model IV Tomahawk LACM.
If you don't mind,what's your facebook id??

Thanks for clarification ....

It makes sense ... Didn't know that Americans have started to use SAR ..

Anyways Mr Prasun has mentioned in his blog that SAR gives capability to operate in Sea state 6 ( which is simply great ...)

I am kind of Caveman ....have no fb id ( never had need to create one ...)
But may be it's about time ...to join fb !

 

[Omega007]

Thanks for clarification ....

It makes sense ... Didn't know that Americans have started to use SAR ..

I am kind of Caveman ....have no fb id ( never had need to create one ...)
But may be it's about time ...to join fb !

Not much different from me then.I've a facebook account but I rarely log in,it has been more than 8 months since I logged in there.
Actually I've seen that facebook is not kinda my thing,I more like to come here and D F I.
Anyway,can you give me your secondary email id??

 

[Indo-guy]

Not much different from me then.I've a facebook account but I rarely log in,it has been more than 8 months since I logged in there.
Actually I've seen that facebook is not kinda my thing,I more like to come here and D F I.
Anyway,can you give me your secondary email id??

sure here it is
dhananjay2312@rediffmail.com

@Indo-guy
Look bro,it's almost certain that Nirbhay is gonna make use of a X band frequency agile SAR seeker as its DSMAC illumination device for terminal guidance.But WHY??One could only speculate for the time being.I've already posted my opinion in this thread in response to @mafiya.
I'm posting my opinion again.But this is just speculation.

Ok,LACMs use DSMAC technique for terminal guidance.Now as you know by now,DSMAC is a technique and not a hardware.In layman terms,it means matching prefed images in its mission computer with the image taken by the missile on scene-correlation in a single word.
Now one could either use some sort of optical device or a SAR seeker onboard the LACM for taking the images.In SAR imaging,one uses the radar waves to take spatial images of an objective or in other words,SAR means using the radar like a video camera.

Now SAR has got several advantages over regular optical sensors.For example,
1.Optical seekers' efficacy is significant in cloudy weather but SAR can very easily work perfectly in bad weather without any significant degradation in performance.

2.Optical seekers can be fooled more easily by applying smoke,special aerosauls or optical camouflage.But SAR seekers can not be fooled that easily.
These are to name a few.There could be other reasons too which I may not be aware of.

Hope I could help you.

Oh and by the way,very recently the Americans. have started to use SAR seekers in their latest model IV Tomahawk LACM.
If you don't mind,what's your facebook id??

what about the flipside such that X Band radar can actually be jammed ?

 

[Omega007]

sure here it is
dhananjay2312@rediffmail.com




what about the flipside such that X Band radar can actually be jammed ?

Thanks man.Actually the latest generation of frequency agile mono pulse seekers are quite harder to jam,especially if the use good ECCM devices.Besides,you can rely on your GPS coordinates and INS in case the seeker is jammed.

In reality,every design solution is a compromise on something else,you have to choose what gives the most bang.In this case,the advantages far outweigh any potential disadvantage.

 

[Indo-guy]

Thanks man.Actually the latest generation frequency agile mono pulse seekers are quite harder jam,especially if the use good ECCM devices.Besides,you can rely on your GPS coordinates and INS in case the seeker is jammed.

In reality,every design solution is a compromise on something else,you have to choose what gives the most bang.In this case,the advantages far outweigh any potential disadvantage.

Indeed ....
Other viewpoint could be as I read somewhere " Solution to a Problem ...actually does not solve the Problem ..actually it replaces original Problem with newer , different Problem "


That's how the evolution goes through never ending , self perpetuating " Problem - Solution- Problem- Solution " cycles ....

Every solution brings its own set of new problems ....and with it brings the opportunities to solve them ....and that's how things evolve ...

 

[Omega007]

Indeed ....
I read somewhere " Solution to a Problem ...actually does not solve the Problem ..actually it replaces original Problem with newer , different Problem "

That's how the evolution goes through never ending , self perpetuating " Problem - Solution- Problem- Solution cycles ...."

Exactly mate,couldn't have put it better myself.
JAI HIND

 

[Indo-guy]

Thanks man.Actually the latest generation of frequency agile mono pulse seekers are quite harder to jam,especially if the use good ECCM devices.Besides,you can rely on your GPS coordinates and INS in case the seeker is jammed.

In reality,every design solution is a compromise on something else,you have to choose what gives the most bang.In this case,the advantages far outweigh any potential disadvantage.

Have been trying read more abour Monopulse X Band SAR

again came across some pics from Mr Prasun's blog posted on some other defence website ....

This seeker by Datapatterns is already being used in Brahmos ...it may be used in Nirbhay also

 

[Omega007]

Have been trying read more abour Monopulse X Band SAR

again came across some pics from Mr Prasun's blog posted on some other defence website ....

This seeker by Datapatterns is already being used in Brahmos ...it may be used in Nirbhay also

When it comes to brochure collection and giving out well thought out no-nonsense assessments,no one can beat it to Prasun K Sengupta.His assessments rarely come out wrong.

 

[Indo-guy]

When it comes to brochure collection and giving out well thought out no-nonsense assessments,no one can beat it to Prasun K Sengupta.His assessments rarely come out wrong.

Indeed . His repertoire of knowledge is awesome !
But I find it funny when people ask him all sort of questions as if he is a fortune-teller ....especially those kind which are generally reserved for astrologers ...

People actually ask for his personal opinion on non technical matters e. what policy Narendra Mody / NDA should adopt and so on ....

( I guess that's because he has build great reputation for himself ....)

 

[Omega007]

Indeed . His repertoire of knowledge is awesome !
But I find it funny when people ask him all sort of questions as if he is a fortune-teller ....especially those kind which are generally reserved for astrologers ...

People actually ask for his personal opinion on non technical matters e. what policy Narendra Mody / NDA should adopt and so on ....

( I guess that's because he has build great reputation for himself ....)

Yeah.And even then his assertions have come true artlest over 90% of times.