Why Don't We Have Land Based Positioning Systems?

[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

__

Henry Wilson DSc.

[kefischer]

There are very large areas in the world,
and even in heavily populated areas, where
there is no cell signal available (because
of topology).

[Ignorant Raving Crackpot]

It has already been explained to you several times how Differential GPS works.
https://en.wikipedia.org/wiki/Differential_GPS

[Sam Wormley]

On 7/24/15 4:29 PM, Henry Wilson DSc. wrote:
> The advantages of a satellite based GPS is that it can be detected at almost
> any point on Earth, independent of terrain.

Alternatives include e-Loran and inertial guidance system. The latter
are expected to become more accurate than GPS/GLONASS/Galileo/Beidou
in the next few years in many application including ballistic missile
systems.


--

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to the discussion of physics, news from the physics
community, and physics-related social issues.

[ji...@specsol.spam.sux.com]

In sci.physics Sam Wormley <swor...@gmail.com> wrote:
> On 7/24/15 4:29 PM, Henry Wilson DSc. wrote:
>> The advantages of a satellite based GPS is that it can be detected at almost
>> any point on Earth, independent of terrain.
>
> Alternatives include e-Loran and inertial guidance system. The latter
> are expected to become more accurate than GPS/GLONASS/Galileo/Beidou
> in the next few years in many application including ballistic missile
> systems.

The eLORAN system is European, not anywhere else, is only in the preliminary
implementation stage, and has an accuracy of about +/- 8 meters ass hole.

If you want high accuracy ( +/- 10 cm) in a local area, anyone with
the slightest bit of sense would use a transportable DGPS reference
station, ass hole.



--
Jim Pennino

[Simeom]

google Omnitracks

[Sylvia Else]

I find it difficult to reconcile "grid of towers" and "cheap".

Even if actual mobile phone towers were used, I doubt the owners would
allow that for free.

Significant errors would be induced by reflections.

Sylvia.

[rotchm]

On Friday, July 24, 2015 at 6:29:21 PM UTC-4, Henry Wilson DSc. wrote:
> The advantages of a satellite based GPS... However ...land based
> system would be perfectly suitable and much cheaper and more accurate...

> Why the heck hasn't someone set this kind of system up already

You are ill informed.

There are many such land based systems. Many here have enumerated some.
In the US, there are also many military (high precision/local atomic clock) based systems too.

[Sam Wormley]

On 7/24/15 5:39 PM, ji...@specsol.spam.sux.com wrote:
>
> The eLORAN system is European, not anywhere else, is only in the preliminary
> implementation stage, and has an accuracy of about +/- 8 meters ass hole.
>
> If you want high accuracy ( +/- 10 cm) in a local area, anyone with
> the slightest bit of sense would use a transportable DGPS reference
> station, ass hole.

The jimp misses the important point that inertial guidance system
will eventually overtake GPS.

U.S. Secretary of Defense Wants to Move Past GPS to MEMS-Based
Navigation, PNT Experts Doubtful
> http://www.insidegnss.com/node/4553

> Ashton Carter, the new U.S. Secretary of Defense has been making
> clear he supports moving past GPS to a disbursed network based on
> microelectromechanical systems or MEMS for position, navigation, and
> timing (PNT) information.
>
> Carter, who was tapped to lead the Pentagon in February, appears to
> have first publically floated the idea a year ago, about six months
> after leaving the Department of Defense (DoD).
>
> “I hate GPS,” Carter said during a wide-ranging conversation about
> innovation in June 2014. “The idea that we are all hooked to a
> satellite — formerly bought by me to my great resentment — in a
> semi-synchronous orbit that that doesn’t work in certain
> circumstances, does not work indoors or in valleys in Afghanistan, is
> ridiculous.”

[kefischer]

On Fri, 24 Jul 2015 21:24:50 -0600, Sam Wormley <swor...@gmail.com>
wrote:

>On 7/24/15 5:39 PM, ji...@specsol.spam.sux.com wrote:
>>
>> The eLORAN system is European, not anywhere else, is only in the preliminary
>> implementation stage, and has an accuracy of about +/- 8 meters ass hole.
>>
>> If you want high accuracy ( +/- 10 cm) in a local area, anyone with
>> the slightest bit of sense would use a transportable DGPS reference
>> station, ass hole.
>
>
> The jimp misses the important point that inertial guidance system
> will eventually overtake GPS.

Except that no inertial guidance system
is drift-free,. and needs indexed routinely.

Things that only need an hour or less
are not affected much, but without some
data input, the systems will be way off
in a few hours.

> U.S. Secretary of Defense Wants to Move Past GPS to MEMS-Based
> Navigation, PNT Experts Doubtful
> > http://www.insidegnss.com/node/4553
>
> > Ashton Carter, the new U.S. Secretary of Defense has been making
> > clear he supports moving past GPS to a disbursed network based on
> > microelectromechanical systems or MEMS for position, navigation, and
> > timing (PNT) information.
> >
> > Carter, who was tapped to lead the Pentagon in February, appears to
> > have first publically floated the idea a year ago, about six months
> > after leaving the Department of Defense (DoD).
> >
> > “I hate GPS,” Carter said during a wide-ranging conversation about
> > innovation in June 2014. “The idea that we are all hooked to a
> > satellite — formerly bought by me to my great resentment — in a
> > semi-synchronous orbit that that doesn’t work in certain
> > circumstances, does not work indoors or in valleys in Afghanistan, is
> > ridiculous.”

The Differential GPS systems may be used
in regions where GPS signal is lost (now or in the
future), but with the large user base, the newer
GPS/Glonass receivers will dominate the market
for quite a while.

[Helmut Wabnig]

On Sat, 25 Jul 2015 08:29:27 +1000, Henry Wilson DSc. <hw@....> wrote:

Too late, Henry. it's already there.
https://www.abatec-ag.com/inmotiotec-rtls/lpm-team/motiotrac-team/motiotrac-team-funktionsprinzip/


w.

[ji...@specsol.spam.sux.com]

In sci.physics Sam Wormley <swor...@gmail.com> wrote:

> On 7/24/15 5:39 PM, ji...@specsol.spam.sux.com wrote:
>>
>> The eLORAN system is European, not anywhere else, is only in the preliminary
>> implementation stage, and has an accuracy of about +/- 8 meters ass hole.
>>
>> If you want high accuracy ( +/- 10 cm) in a local area, anyone with
>> the slightest bit of sense would use a transportable DGPS reference
>> station, ass hole.
>
>
> The jimp misses the important point that inertial guidance system
> will eventually overtake GPS.

The ass hole misses the very important point that an inertial guidance system
has to be periodically initialized with an accurate reference.



--
Jim Pennino

[kenseto]

On Friday, July 24, 2015 at 6:29:21 PM UTC-4, Henry Wilson DSc. wrote:

The cell towers are synched by the GPS.

[Daniel S. Riley]

Sylvia Else <syl...@not.at.this.address> writes:
> On 25/07/2015 8:29 AM, Henry Wilson DSc. wrote:
>> 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.

Many mobile phones already do this, combining cell assisted GPS (using
the cell network for initial clock, rough location and satellite
ephemerides to speed up time-to-first-fix), cell tower multilateration,
and WiFi positioning. See, for example,

http://www.edepot.com/iphone.html#iPhone_A-GPS

> Even if actual mobile phone towers were used, I doubt the owners would
> allow that for free.

Data access charges may apply.

-dan

[HG Wilson]

On Sat, 25 Jul 2015 10:29:45 +0200, Helmut Wabnig <hwabnig@.- --- -.dotat>
wrote:

>https://www.abatec-ag.com/inmotiotec-rtls/lpm-team/motiotrac-team/motiotrac-team-funktionsprinzip/

OK, that's good. I don't speak German but I can see the idea from the diagram.

Why can't that be used on a much larger scale? I can visualize many
applications for such a cheap system, such as preventing car accidents, spying
and general locating. The problem is to get around the LOS requirement.

[HG Wilson]

On Sat, 25 Jul 2015 12:06:21 +1000, Sylvia Else <syl...@not.at.this.address>
wrote:

>On 25/07/2015 8:29 AM, Henry Wilson DSc. wrote:

>>
>> 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
>>
>> __
>>
>> Henry Wilson DSc.
>>
>
>
>I find it difficult to reconcile "grid of towers" and "cheap".

Even you should realize htat it is cheaper to build a tower than to send an
atomic clock into orbit.

Most of the towers already exist, anyway.

>Even if actual mobile phone towers were used, I doubt the owners would
>allow that for free.

Why should they?

>Significant errors would be induced by reflections.

Maybe...but I'm sure that could be overcome by always using the stronger signal
of each frequency.

>Sylvia.

[Tom Roberts]

On 7/24/15 7/24/15 6:39 PM, ji...@specsol.spam.sux.com wrote:
> The eLORAN system is European, not anywhere else,

... initially defined at the U.S. Coast Guard.

The "e" is "enhanced", not "european". I don't know what deployment plans are --
Google is your friend.

> is only in the preliminary
> implementation stage,

LORAN itself debuted during WW2. I certainly remember it in the 1950s-60s. I
don't know if it is still operating; certainly it is vastly outclassed by GPS.

> and has an accuracy of about +/- 8 meters

Yes. Worse than standard GPS and much worse than differential GPS (where available).

Its primary claim to fame is that it operates independently of GPS, GLONASS,
Galileo, or any other satellite system, and is designed to be much less jammable.

> If you want high accuracy ( +/- 10 cm) in a local area, anyone with
> the slightest bit of sense would use a transportable DGPS reference
> station,

Yes. For instance, most major harbors have it and require large ships to use it.

Fortunately my old 19' sloop was exempt, as it had no electricity
at all. Of course I had to dodge any big guys as their radars
could not see a small wooden boat and their lookouts might not....


Tom Roberts

[Thomas Heger]

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

[Fabian Russell]

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.

[Fritz Köhler]

Tom Roberts wrote:

>> and has an accuracy of about +/- 8 meters
>
> Yes. Worse than standard GPS and much worse than differential GPS (where
> available).

This is splendid. I can live with that. Gives more peace around the world.

> Its primary claim to fame is that it operates independently of GPS,
> GLONASS, Galileo, or any other satellite system, and is designed to be
> much less jammable.

Yes, especially that.

[gilber34]

On 7/26/2015 2:16 AM, Thomas Heger wrote:
> 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.

because the cost of deploying GPS is on the US GOV.

>> 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.

not so, do the math.

>>
>> 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.

not high accuracy.

Clock synching would be much easier
>> and the
>> distances between broadcast points is fixed and not continually
>> changing as
>> with the GPS.

clocksync is not a key issue.

>> 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

cost. frequency bands. size and cost of receiver. tower rental.
besides one can just look and see where the players are.

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

wrong, it is precisely a question of Cost, Accuracy, and usability. Who
is going to pay ?

"Technology dominance" is not a factor, GPS is old technology now.

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

not "entire"

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

there are already 3 other systems up there + deployed, in use.

[Henry Wilson DSc.]

On Tue, 28 Jul 2015 10:17:33 -0500, gilber34 <inv...@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.