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Re: Why Don't We Have Land Based Positioning Systems?

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  Re: Why Don't We Have Land Based Positioning Systems? Thomas Heger <ttt_heg@web.de> - 2015-07-26 09:16 +0200
    Re: Why Don't We Have Land Based Positioning Systems? Fabian Russell <root@localhost.localdomain> - 2015-07-26 07:45 +0000
    Re: Why Don't We Have Land Based Positioning Systems? Henry Wilson DSc. <hw@....> - 2015-07-29 07:45 +1000

#509535 — Re: Why Don't We Have Land Based Positioning Systems?

Am 25.07.2015 00:29, schrieb Henry Wilson DSc.:
> The advantages of a satellite based GPS is that it can be detected at almost
> any point on Earth, independent of terrain. However there are many
> applications where a local land based system would be perfectly suitable and
> much cheaper and more accurate.
> For instance, players on a football field are now being tracked with GPS
> during the game. That could be far better achieved with a triangle of
> transmitters set around the playing field. This would eliminate the inherent
> delays experienced when using GPS.
>
> By broadcasting time signals from a grid of towers, such as those already set
> up for mobile phones, a simple receiver could locate a person just about
> anywhere and with high accuracy.  Clock synching would be much easier and the
> distances between broadcast points is fixed and not continually changing as
> with the GPS.
> Why the heck hasn't someone set this kind of system up already when most of
> the towers are already in place. It would not even require the extreme
> accuracy of atomic clocks since they cold be .constantly synched with a master
> clock


It is not a question of usability, cheapness or accuracy, but a question 
of technological dominance the USA claims to posses.

Their entire defence system is based on their assumed advanced 
technology and what they exclusively control.

So, why should the US-military allow or build competing systems to GPS, 
that they exclusively control?


TH

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#509543

On Sun, 26 Jul 2015 09:16:35 +0200, Thomas Heger wrote:


> 
> So, why should the US-military allow or build competing systems to GPS, 
> that they exclusively control?
> 

For one thing, GPS is able to be jammed or otherwise subject to a
deliberate interference and this would constitute a serious threat
to US military operations.

The Chinese are said to be devoting much resources to jamming GPS
and US satellite links in general.  They realize that the US
military is thoroughly dependent on satellite communication
and navigation.  To thwart GPS would be a great advantage to them.

For the US military GPS is perhaps its greatest weakness.

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#510090

On Tue, 28 Jul 2015 10:17:33 -0500, gilber34 <invalid@invalid.com> wrote:

>as

What a stupid post. Don't you have any idea about anythng?

A satellite PS is useful internationally. It is not essential within national
boundaries.

__

Henry Wilson DSc.

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