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Comment by andyjohnson0 | Hacker News Reader

I didn't understand this. How would the GPS system allow the US to know the location of Pakistani soldiers? GPS satellites only transmit and GPS receivers only receive - there is no return path that would disclose the location. What am I missing?

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As far as I can tell, all the online reports have been written 15+ years after the fact, and they all just quote one another; I suspect the journalists may be mistaken.

It's worth bearing in mind the Kargil War took place in 1999, and GPS Selective Availability wasn't turned off until May 2000. It might be that India asked for the SA seed key so their own forces/missiles could navigate more accurately, but were denied?

IIRC, with SA on, accuracy was to within 100 meters. And that's enough for troop movements but not accurate enough for missiles and artillery. So using it for land navigation would have been fine. It's sounding like it was a case of "We want it because we want it"

Kargil is one of the highest battlefields on Earth. I don't think I'd compare Himalayan warfare to "land navigation".

https://en.wikipedia.org/wiki/Kargil_War

https://en.wikipedia.org/wiki/Mountain_warfare#Kashmir_confl...

> The most dangerous and volatile of all mountain conflicts involves the ongoing one between India and Pakistan over the Kashmir region.

It's a generic term meaning "How do I get my troops from here to there" either by vehicle or marching, such that they don't get lost and arrive when needed.

This is the classic way with map + compass. GPS just makes it easier. https://www.youtube.com/watch?v=xSNohNPqWlU

There are many scenarios, but here's a simple one. Boots on the ground.

You have men on the ground who can see the enemy position, they need to know exactly where they are to be able to know exactly where the enemy is. Without GPS you are relying on visual points of reference against maps of shaky providence.

Boots on the ground don't need to be accurate to within 1cm. If a normal human is within 10 meters they can nearly always figure things out. In fact if humans are that close it is because you don't actually know where the enemy is and you need the humans to find them - otherwise you would have a plane drop a bomb on them.

Where you need more accuracy is when you want something at a long distance to do something - drop a bomb or something.

https://m.timesofindia.com/home/science/How-Kargil-spurred-I...

This seems to have moderately more information. It seems like maybe they wanted to use GPS capabilities in their guided weapons systems, and the US would not permit it or perhaps threatened to disable the system in that theater? It’s a bit confusing and fuzzy.

Also because swearing-in ceremony of Barack Obama as US President in January 2009 had a disastrous impact on the test-firing of the BrahMos supersonic missile https://www.thehindubusinessline.com/news/national/how-obama...

> But an apprehensive US official turned down the request and told Kalam: “Sorry Dr Kalam, we will give you good lunch and dinner, but no Craig computer.”

> Kalam came back empty-handed, but went on to develop the Pace Plus computer with help from the Indian Institute of Science and others in two years. And, Pace Plus proved to be 20 times faster than Craig!

This type of thing sounds incredibly childish and jingoistic to my American ears. Does it read better to folks who learned to speak English in India, or is it just really awful writing?

Also, as best I can tell, there is no "Craig" super computer. Does the author mean Cray? And if so, why was the scientist asking the USG? You would normally want to get such computers from the manufacturer, not a foreign government, however friendly.

That's the usual state of news reporting. People just love discourse of conspiracy over here.

It's not a conspiracy. The sale of Cray supercomputers was indeed blocked by the US Government. Just because the article is badly written doesn't negate the facts on the ground.

http://www.rediff.com/computer/dec/18super.htm

I agree that it is awful writing. I hope the article above is written better.

> Does the author mean Cray? And if so, why was the scientist asking the USG? You would normally want to get such computers from the manufacturer, not a foreign government, however friendly.

It's not possible to directly purchase from manufacturers if the US Government is going to block the purchase on various grounds. Don't forget that there was a period where sanctions and arms embargo was also imposed on India. It's a different thing that today the US considers India a "strategic partner" but it wasn't always the case.

As far as Cray goes, they even setup an award in the name of the scientist mentioned in the article (who also served as the President of India from 2002 to 2007 [1]): https://www.cray.com/blog/cray-hpc-awards-honor-achievements...

[1] https://en.wikipedia.org/wiki/A._P._J._Abdul_Kalam

This is helpful historical context, and indeed a much better article. My thanks.

> Also, as best I can tell, there is no "Craig" super computer. Does the author mean Cray? And if so, why was the scientist asking the USG?

Because these things all have export controls. You don't see it if your shipping to a domestic address, but even in Canada I have to certify I won't re-export it when I buy electronic components from US suppliers.

Its not about location of foot soldiers. Although the article highlights about GPS, it is mapping in general. India wanted terrain and altitude data for making strategy.

Only a guess, but at that time wasn't the GPS signal intentionally degraded for non-US-military use, with reduced accuracy? Perhaps they're talking about the more precise signal, which the US didn't let them use.

Yes, "selective availability" was still in use then - but I can't see how its use or not would disclose a GPS user's position.

"I need a missile strike. My position according to GPS is x and the Pakistani you should hit are 920m straight north of me according to my rangefinder."

GPS broadcasts several signals, the higher precision ones are encrypted - until 1999 GPS was encrypted at much lower resolution but the army and armies it shares its tech with still operate at a higher resolution.

The US can lock countries out of higher resolution GPS at will - this (and GLONASS) make sense because of it.

I would speculate that India wanted access to the encrypted military GPS signal, which would have given them 10-1000 times more accurate guidance for precision weapons.

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