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Does this make anyone else nervous?
Maybe Trump has a point when he says we should stop letting China steal our technology.
[1] https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...
So China has the technology to destroy satellites [1], and is developing alternatives to US satellites. Does this make anyone else nervous? Maybe Trump has a point when he says we should stop letting China steal our technology. [1] https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...
Any country that can launch a satellite has a technology to destroy one. It's called a missile. You don't even need to go to orbit - just intersect the orbit of the target and dump a bucket of nails in its path.
India did something similar a few months ago. Each country wants to build it's own GPS for military purposes. At some point we have to stop calling it 'Global' Positioning System.
Navstar (owned by USDoD, what is commonly called "GPS"), GLONASS and soon Galileo all have global coverage.
India did something similar a few months ago. Each country wants to build it's own GPS for military purposes. At some point we have to stop calling it 'Global' Positioning System.
So China has the technology to destroy satellites [1], and is developing alternatives to US satellites. Does this make anyone else nervous? Maybe Trump has a point when he says we should stop letting China steal our technology. [1] https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...
>... even precision missiles. So if GPS were to be jammed, or disabled by a hack into the ground control systems -- PLA missiles would still work just fine. Hmm.
https://en.wikipedia.org/wiki/CoCom#Legacy
Edit: I'm wrong.
>... even precision missiles. So if GPS were to be jammed, or disabled by a hack into the ground control systems -- PLA missiles would still work just fine. Hmm.
Due to COCOM limits, GPS was never an option for China to use on their missiles. https://en.wikipedia.org/wiki/CoCom#Legacy Edit: I'm wrong.
GPS satellites are transmit only so they can’t impose such limits directly it’s device manufacturers that implement COCOM.
It’s interesting and odd to me that Beidou requires two-way communication, as opposed to other satellite tracking systems where the receivers are purely passive and satellites only transmit, not receive. Is there an explanation for why this was done?
It’s interesting and odd to me that Beidou requires two-way communication, as opposed to other satellite tracking systems where the receivers are purely passive and satellites only transmit, not receive. Is there an explanation for why this was done?
It doesn't make any sense to have the ground station transmit to figure out its location. To give a baseline, that's how the original analogue COSPAS SARSAT worked last century, using doppler measurements to get a location over time - and its accuracy was appalling, a human operator has to use equipment to narrow down where the signal is, it takes significant time to get a 1 nautical mile search area. Which is much better than "I dunno, in the sea?" for a lost ship or plane, but you're still going to need a serious search-and-rescue operation to find anybody.
A modern digital COSPAS SARSAT system you may have seen if you're a serious hiker or outback flyer just does GPS, it uses GPS to figure out where it is, then sends a digital signal that says "I need help, here are my GPS co-ordinates" hence the slogan "Taking the search out of search and rescue".
It’s interesting and odd to me that Beidou requires two-way communication, as opposed to other satellite tracking systems where the receivers are purely passive and satellites only transmit, not receive. Is there an explanation for why this was done?
The article talks about how it can be used to send messages but my first thought is that it could allow tracking of receivers. A scary thought if it does achieve widespread adoption.