John wrote:I have not heard anywhere that it can fly at lower altitudes was under impression, it was quasi ballistic missile it probably has some limited maneuvering in terminal phase.
Not lower as in cruise missile/sea skimming altitude but there were some trajectory images/graphs that showed that the missile trajectory flattened out during descent. Here is the image (from
http://www.jamestown.org/programs/china ... 31ceb95794)
Now AFAIK, and it is just my opinion, the difference between the DF-21 vs. Shaurya is that the DF21 follows a ballistic trajectory for the most part and achieves similar altitude (exo atmospheric) otoh the Shaurya never leaves the atmosphere and therefore does not have to deal with issues of reentry speeds and heat which are a problem for RF seekers. IIRC, the cruise altitude for the Shaurya was around 40km @ M7.5, I could not find a similar detail on the DF-21. IOWs, the DF-21 is like a late model Prithvi based on seeing a Prithvi's trajectory from one of Arun S's? (Not sure) graphs, the Shaurya otoh, is somewhat different.
Added later: You can ignore the above para - the DF-21, SHaurya and Iskander all seem to follow a similar flight path - the Shaurya too has an apogee of about 200km - just found Arun S's slides.
But given its flights altitude most radars should be able to pick it up at least couple hundred kms' away may not be able to track it due its lower RCS and speed, so not sure where you got 20 second window from. Reaction time for SAM varies from what i recall Barak was advertised as having the shortest reaction time, some where about 3 to 6 seconds (when in standby mode) to track and fire a missile to engage a target. There is RSN video in the web that shows that.
I got the 20 second window from the paper and book that I linked to previously
http://www.nap.edu/openbook.php?record_id=6195&page=56:
As for DF-31D the main difference over Shaurya is its speed and range and the fact that chinese have developed some type of active seeker with mid course guidance (via satellite?) to fit into it.
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Well, I'd also like to know the apogee of both these missiles. AFAIK, Shaurya does not exceed 50kms, but I could be wrong, perhaps it goes much higher and then comes down to maintain a 50km cruise altitude. More importantly, since the DF-21 has to cover a much longer range, it will require more elaborate guidance since time to target will be much more. Otoh, Shaurya, can cover 750km in a few 100 seconds.
My question is - if Shaurya type is considered effective against land based targets, then why not capital ships as well? Ship defences are no more robust than land based systems, so if Shaurya is good enough for these, it should be good enough against ships? Second issue is - acquiring and maintaining lock on a mobile target. Can't this be achieved via a decent seeker? Won't other hypersonics find the same issue - Brahmos II for example? Afterall, a ship is not exactly a fast mover, and @ around a range of 1000km, which the Shaurya can cover in about 8 minutes or so, the ship cannot move more than a few km in that time.
If we take a Brahmos, which covers about half the distance in the same time frame, how does it lock on to a given ship, considering the ship could have moved a similar distance in the allotted time?
