OT How does GMaps know elevation?

[rbowman]

On 08/04/2019 03:02 AM, Rob wrote:

Rod Speed <rod.speed.aaa@gmail.com> wrote:
Or do municiplities send it updates when they construct new streets?

Not send google so much as update their database and google accesses those.
We have seen it take a while before the google map is updated with new ones.

I guess it depends on the quality of your local database.
Here we see new streets and quarters on Google Maps that do not yet
exist in reality (but have been planned and will be built).

I do a lot of work with local GIS departments and the quality is
extremely variable. Some are on top of it and others are completely out
of their depth. At least one uploads their edits to ESRI and not Google.
Google puts their dispatch center in the wrong place so they don't
exactly trust them.


There are several big players like HERE (formerly NavTeq) and TeleAtlas.
Licensing their data isn't cheap and depends on how frequently you want
it updated. TIGER/Line is the US Census Department and the data is free
but the update cycle is slow. It's interesting to take the data for the
same area from several different sources, overlay it, and see where it
differs.

 

[Rob]

Rod Speed <rod.speed.aaa@gmail.com> wrote:

"Rob" <nomail@example.com> wrote in message
news:slrnqkd7o9.20b.nomail@xs9.xs4all.nl...
Rod Speed <rod.speed.aaa@gmail.com> wrote:
Or do municiplities send it updates when they construct new streets?

Not send google so much as update their database and google accesses
those.
We have seen it take a while before the google map is updated with new
ones.

I guess it depends on the quality of your local database.

The local database is fine, it just takes google a long time to use the
updates.

It likely is all coincidence. They fetch the info once every so
many years, and it could include very recent information or it could
take several years.

Here we see new streets and quarters on Google Maps that do
not yet exist in reality (but have been planned and will be built).

That not necessarily due to the quality of the local database.

We saw the google car show up again here almost 18 months
ago, after it had been here previously more than 10 years
previously. The second time they only zoomed thru some
of the main streets in town and didn’t even bother to
visit the new roads and houses.

This is not at all related to it. The google car does not map the
streets, it collects data and pictures.

 

[Rod Speed]

"Rob" <nomail@example.com> wrote in message
news:slrnqkegpk.ssl.nomail@xs9.xs4all.nl...

Rod Speed <rod.speed.aaa@gmail.com> wrote:


"Rob" <nomail@example.com> wrote in message
news:slrnqkd7o9.20b.nomail@xs9.xs4all.nl...
Rod Speed <rod.speed.aaa@gmail.com> wrote:
Or do municiplities send it updates when they construct new streets?

Not send google so much as update their database and google accesses
those.
We have seen it take a while before the google map is updated with new
ones.

I guess it depends on the quality of your local database.

The local database is fine, it just takes google a long time to use the
updates.

It likely is all coincidence. They fetch
the info once every so many years,

Why would they do it so slowly ?

And the google maps don’t show the new ones in bursts like that.

and it could include very recent information or it could take several
years.

Here we see new streets and quarters on Google Maps that do
not yet exist in reality (but have been planned and will be built).

That not necessarily due to the quality of the local database.

We saw the google car show up again here almost 18 months
ago, after it had been here previously more than 10 years
previously. The second time they only zoomed thru some
of the main streets in town and didn’t even bother to
visit the new roads and houses.

This is not at all related to it. The google car does not map the
streets, it collects data and pictures.

Duh.

 

[Peeler]

On Mon, 5 Aug 2019 07:36:29 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


> Duh.

Yep, those three letters sum up your entire existence, senile cretin!

--
Sqwertz to Rot Speed:
"This is just a hunch, but I'm betting you're kinda an argumentative
asshole.
MID: <ev1p6ml7ywd5$.dlg@sqwertz.com>

 

[Mike S]

On 7/30/2019 1:19 PM, Scott Lurndal wrote:

Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
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micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

 

[rbowman]

On 08/05/2019 11:20 PM, Mike S wrote:

On 7/30/2019 1:19 PM, Scott Lurndal wrote:
Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
In-Reply-To: <ho21ke161mdv4psg19j9u7silc99mt9alf@4ax.com
Content-Language: en-GB
X-Received-Bytes: 1151
X-Received-Body-CRC: 1553258581

micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

 

[Swer]

"rbowman" <bowman@montana.com> wrote in message
news:gqtgobFe6o5U1@mid.individual.net...

On 08/05/2019 11:20 PM, Mike S wrote:
On 7/30/2019 1:19 PM, Scott Lurndal wrote:
Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
In-Reply-To: <ho21ke161mdv4psg19j9u7silc99mt9alf@4ax.com
Content-Language: en-GB
X-Received-Bytes: 1151
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micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That’s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.

 

[Peeler]

On Wed, 7 Aug 2019 03:28:15 +1000, Sewer, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

That˘s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.

"GPS"? Does that stand for "Geriatric Pile of Shit" in your case, senile
Rodent?

--
MrTurnip@down.the.farm about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID: <ps10v9$uo2$1@gioia.aioe.org>

 

On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:

"rbowman" <bowman@montana.com> wrote in message
news:gqtgobFe6o5U1@mid.individual.net...
On 08/05/2019 11:20 PM, Mike S wrote:
On 7/30/2019 1:19 PM, Scott Lurndal wrote:
Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
In-Reply-To: <ho21ke161mdv4psg19j9u7silc99mt9alf@4ax.com
Content-Language: en-GB
X-Received-Bytes: 1151
X-Received-Body-CRC: 1553258581

micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That’s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.

Why is laser measuring much more accurate than GPS? They both use
light and clocks.
Eric

 

[Scott Lurndal]

etpm@whidbey.com writes:

On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:



How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That’s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.
Why is laser measuring much more accurate than GPS? They both use
light and clocks.

GPS doesn't use lasers. The receiver triangulates signals from multiple
satellites to determine x, y and z coordinates of the receiver.

The z coordinate (altitude) is not very accurate

http://gpsinformation.net/main/altitude.htm

 

On Tue, 06 Aug 2019 19:30:56 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:

etpm@whidbey.com writes:
On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:



How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That’s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.
Why is laser measuring much more accurate than GPS? They both use
light and clocks.

GPS doesn't use lasers. The receiver triangulates signals from multiple
satellites to determine x, y and z coordinates of the receiver.

The z coordinate (altitude) is not very accurate

http://gpsinformation.net/main/altitude.htm

I know GPS doesn't use lasers. It uses radio waves which are light and
move the same speed as lasers. What is it about using lasers that
makes them more accurate?
Eric

 

[Swer]

<etpm@whidbey.com> wrote in message
news:k8ljkedtv1dhiibk1v4cst0vloqenjoa0v@4ax.com...

On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:



"rbowman" <bowman@montana.com> wrote in message
news:gqtgobFe6o5U1@mid.individual.net...
On 08/05/2019 11:20 PM, Mike S wrote:
On 7/30/2019 1:19 PM, Scott Lurndal wrote:
Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
In-Reply-To: <ho21ke161mdv4psg19j9u7silc99mt9alf@4ax.com
Content-Language: en-GB
X-Received-Bytes: 1151
X-Received-Body-CRC: 1553258581

micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing
data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That's because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.

Why is laser measuring much more accurate than GPS?

Because the laser is the most accurate way to measure things.

> They both use light

GPS doesn't. It used radio waves.

> and clocks.

Yes.

 

[Swer]

<etpm@whidbey.com> wrote in message
news:1fvjkedv5a8q9b7j8kejg052trlut667q1@4ax.com...

On Tue, 06 Aug 2019 19:30:56 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:

etpm@whidbey.com writes:
On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:



How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine
altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede
the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in
years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That's because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.
Why is laser measuring much more accurate than GPS? They both use
light and clocks.

GPS doesn't use lasers. The receiver triangulates signals from multiple
satellites to determine x, y and z coordinates of the receiver.

The z coordinate (altitude) is not very accurate

http://gpsinformation.net/main/altitude.htm
I know GPS doesn't use lasers. It uses radio waves which are light and
move the same speed as lasers. What is it about using lasers that
makes them more accurate?

It's a direct ping from the satellite or plane with the laser.
With GPS its continuous radio waves with varying propagation
effects. That's why you need more than one visible satellite
with GPS.

 

[rbowman]

On 08/06/2019 01:31 PM, etpm@whidbey.com wrote:

On Wed, 7 Aug 2019 03:28:15 +1000, "Swer" <swer@gmail.com> wrote:



"rbowman" <bowman@montana.com> wrote in message
news:gqtgobFe6o5U1@mid.individual.net...
On 08/05/2019 11:20 PM, Mike S wrote:
On 7/30/2019 1:19 PM, Scott Lurndal wrote:
Andy Burns <usenet@andyburns.uk> writes:
Thunderbird/60.8.0
In-Reply-To: <ho21ke161mdv4psg19j9u7silc99mt9alf@4ax.com
Content-Language: en-GB
X-Received-Bytes: 1151
X-Received-Body-CRC: 1553258581

micky wrote:

Google doesn't have GPS devices at
any random location the user picks

Every user carrying a GPS enabled android device is crowd-sourcing data
for google, if someone's been there, google will know the altitude.

Nonsense.

How so? Wikipedia says this:

"Global Positioning System (GPS) receivers can also determine altitude
by trilateration with four or more satellites. In aircraft, altitude
determined using autonomous GPS is not reliable enough to supersede the
pressure altimeter without using some method of augmentation"

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

Barometric altimeters aren't that great either. I haven't flown in years
so the procedure might have changed but airports would have their
elevation prominently marked. Part of the preflight was setting the
altimeter to match.

That’s because air pressure changes. Laser height measuring from
satellites and planes for mapping works fine and is a lot more
accurate than GPS.
Why is laser measuring much more accurate than GPS? They both use
light and clocks.
Eric

A GPS receiver extrapolates from the satellite constellation. The closer
to the horizon the birds are and the more angular distance separating
them, the better it works. In cities or mountainous terrain the view of
the sky can be limited so it has to work with those overhead. It has
nothing to do with light unless you have an extremely loose definition
of the spectrum.

With a laser you're bouncing the beam off an object.

 

[Peeler]

On Wed, 7 Aug 2019 09:51:56 +1000, Sewer, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

I know GPS doesn't use lasers. It uses radio waves which are light and
move the same speed as lasers. What is it about using lasers that
makes them more accurate?

It's a direct ping from the satellite or plane with the laser.
With GPS its continuous radio waves with varying propagation
effects. That's why you need more than one visible satellite
with GPS.

SOURCE, senile Mr Know-it-all? I KNOW you just looked it up, just so you
could smartass again, you pathological, lonely, senile sow!

--
Website (from 2007) dedicated to the 85-year-old trolling senile
cretin from Oz:
https://www.pcreview.co.uk/threads/rod-speed-faq.2973853/

 

[Peeler]

On Wed, 7 Aug 2019 09:38:11 +1000, Sewer, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

Why is laser measuring much more accurate than GPS?

Because the laser is the most accurate way to measure things.

Dig this, senile troll from Oz: a troll's posts are the most accurate way to
measure the extent of his trolling. They knew that already back then in 2007
when the dedicated that website to you:

https://www.pcreview.co.uk/threads/rod-speed-faq.2973853/

--
dennis@home to retarded senile Rot:
"sod off rod you don't have a clue about anything."
Message-ID: <uV9lE.196195$cx5.41611@fx46.iad>

 

[Mike Coon]

In article <1fvjkedv5a8q9b7j8kejg052trlut667q1@4ax.com>,
etpm@whidbey.com says...

I know GPS doesn't use lasers. It uses radio waves which are light and
move the same speed as lasers. What is it about using lasers that
makes them more accurate?
Eric

Wavelength.

Mike.

 

[Mike Coon]

In article <gquhbaFl21uU1@mid.individual.net>, swer@gmail.com says...

Why is laser measuring much more accurate than GPS?

Because the laser is the most accurate way to measure things.

Did your mummy say "Because I said so!" a lot?

Mike.

 

[Rod Speed]

"Mike Coon" <gravity@mjcoon.plus.com> wrote in message
news:MPG.37b529042a10349977@news.plus.net...

In article <1fvjkedv5a8q9b7j8kejg052trlut667q1@4ax.com>,
etpm@whidbey.com says...

I know GPS doesn't use lasers. It uses radio waves which are light and
move the same speed as lasers. What is it about using lasers that
makes them more accurate?
Eric

Wavelength.

Nope, it's a laser pulse from the plane or satellite, travel time measured.

GPS is continuous transmission with digital encoding on that.

 

[Swer]

Mike Coon <gravity@mjcoon.plus.com> wrote

swer@gmail.com wrote

Why is laser measuring much more accurate than GPS?

Because the laser is the most accurate way to measure things.

Did your mummy say "Because I said so!" a lot?

Nope, both mum and dad quickly worked out that doesn't work with me.

I still remember the mega stoush that happened when I refused
to eat something like spinach. She never tried that again.