Garmin GPS - How to map StreetPilot III latitude/longitude on Google maps?

Author

How to map StreetPilot III latitude/longitude on Google maps?

Karen Wheless

2007-08-19, 4:33 am

How can I take the latitude/longitude provided by the Garmin StreetPilot
III and plug it into Google maps to find the same location in the USA?

For example, what do I plug into google maps when my StreetPilot III reads:
N 32 49.230
W 115 07.061

SKM-PSN#55

2007-08-19, 4:33 am

On Aug 18, 10:35 pm, Karen Wheless <no_s...@airmail.net> wrote:
> How can I take the latitude/longitude provided by the Garmin StreetPilot
> III and plug it into Google maps to find the same location in the USA?
>
> For example, what do I plug into google maps when my StreetPilot III reads:
> N 32 49.230
> W 115 07.061

What you have given is degrees and decimal minutes!
I simply copied your location and entered it in the search bar of
Google maps as a single line:
N 32 49.230 W 115 07.061
Then clicked the search botton and it placed an arrow with the
opportunity to do a, travel too, at the location! It also did a
conversion so you could see the location in decimal degrees and in
degrees minutes seconds!! Your given location appears to be out in
the sticks East of El Centro Calif???

hope this helps,
SKM

SKM-PSN#55

2007-08-19, 4:33 am

On Aug 18, 10:35 pm, Karen Wheless <no_s...@airmail.net> wrote:
> How can I take the latitude/longitude provided by the Garmin StreetPilot
> III and plug it into Google maps to find the same location in the USA?
>
> For example, what do I plug into google maps when my StreetPilot III reads:
> N 32 49.230
> W 115 07.061

One more point,, I entered a location (the center of my home),
which was established by post processing about 600 hours of raw GPS
data and noticed that Google Maps placed their marker about 50 feet
east of the established mark, (looking at the satellite photo)!!!
I also notice that some roads, etc., have an offset where Google maps
sometimes doesn't line up where they are spliced together,,, so,
there is room for some error on Google maps as well as other web maps
and photos!! Just an FYI in the event that your reading falls on
the other side of a river, or road, etc., on Google maps!!!
SKM

Karen Wheless

2007-08-19, 4:33 am

On Sat, 18 Aug 2007 23:39:07 -0700, SKM-PSN#55 wrote:

> On Aug 18, 10:35 pm, Karen Wheless <no_s...@airmail.net> wrote:
>
> What you have given is degrees and decimal minutes!
> Google maps as a single line:
> N 32 49.230 W 115 07.061

Wow. I couldn't figure that out on my own. Everything I tried had failed
but this worked perfectly. Thank you.

I'm not sure why Garmin reports latitude and longitude in degrees and
decimal minutes (why not just decimal degrees or degrees/minutes/seconds)?

But, it is close (it's off by a ten or fifteen yards).

THANK YOU

Kristian M Zoerhoff

2007-08-19, 10:33 am

On 2007-08-19, Karen Wheless <no_spam@airmail.net> wrote:
>
> I'm not sure why Garmin reports latitude and longitude in degrees and
> decimal minutes (why not just decimal degrees or degrees/minutes/seconds)?

Because Garmin decided that's how they wanted to display it, I guess.
Unfortunately, it doesn't look like you can change the lat/long display
on the StreetPilot III, so you're stuck with decimal degrees.

--

__o Kristian Zoerhoff
_'\(,_ kristian.zoerhoff@gmail.com
(_)/ (_)

Cooter

2007-08-19, 10:33 am

FWIW, Google Earth is notorius for being off from known positions, and the
amount varies from location to location. USAPhotoMaps is another application
(free) that uses aerial photography, but it is black and white, and
generally older images than Google. However, I have found it to be much more
accurate.. I think the URL is www.jdmcox.com.

"SKM-PSN#55" <skmort@lanset.com> wrote in message
news:1187507773.879213.45800@x40g2000prg.googlegroups.com...
> On Aug 18, 10:35 pm, Karen Wheless <no_s...@airmail.net> wrote:
>
> One more point,, I entered a location (the center of my home),
> which was established by post processing about 600 hours of raw GPS
> data and noticed that Google Maps placed their marker about 50 feet
> east of the established mark, (looking at the satellite photo)!!!
> I also notice that some roads, etc., have an offset where Google maps
> sometimes doesn't line up where they are spliced together,,, so,
> there is room for some error on Google maps as well as other web maps
> and photos!! Just an FYI in the event that your reading falls on
> the other side of a river, or road, etc., on Google maps!!!
> SKM
>

Frank Tabor

2007-08-19, 10:33 am

On Sun, 19 Aug 2007 10:35:40 -0400, Cooter wrote:

> FWIW, Google Earth is notorius for being off from known positions, and
> the amount varies from location to location. USAPhotoMaps is another
> application (free) that uses aerial photography, but it is black and
> white, and generally older images than Google. However, I have found it
> to be much more accurate.. I think the URL is www.jdmcox.com.

USA Maps has color aerials, where they are available. Mostly Urban areas.

--
Frank Tabor
Q: Why did the chicken cross the road?
A: To see his friend Gregory peck.

Q: Why did the chicken cross the playground?
A: To get to the other slide.

SKM-PSN#55

2007-08-19, 12:33 pm

On Aug 19, 1:19 am, Karen Wheless <no_s...@airmail.net> wrote:
> N 32 49.230 W 115 07.061
>
> Wow. I couldn't figure that out on my own. Everything I tried had failed
> but this worked perfectly. Thank you.
>
> I'm not sure why Garmin reports latitude and longitude in degrees and
> decimal minutes (why not just decimal degrees or degrees/minutes/seconds)?
>
> But, it is close (it's off by a ten or fifteen yards).
>
> THANK YOU

Interesting,,, all three Garmins that I have had (2 etrex models and
now the GPS60) allow me to choose the format of the display, including
UTM which I prefer and use most of the time,,,, even Google Earth
has the UTM option!!!! In fact, as near as I can determine, all of
the web maps use UTM as their underlying master grid????? (when you
see the maps being placed in their smaller squares on the screen, they
are being drawn to a UTM grid)!!! I like UTM because, as long as
you stay within a local UTM zone, it makes it simple to determine
distances,,, so many meters over and so many meters up, or
down,,, or use a calculator with square root function to find the
straight line distance,, which I never worry about when I'm hiking
anyway, ha!!!!!!
Your welcome, SKM

SKM-PSN#55

2007-08-19, 12:33 pm

On Aug 19, 7:35 am, "Cooter" <coo...@yahoo.com> wrote:
> FWIW, Google Earth is notorius for being off from known positions, and the
> amount varies from location to location. USAPhotoMaps is another application
> (free) that uses aerial photography, but it is black and white, and
> generally older images than Google. However, I have found it to be much more
> accurate.. I think the URL iswww.jdmcox.com.
>

Also, on those web sites where you can choose topo and photo I have
noticed, at least for my area, (N. Calif.), that the placement of
survey markers on the topos, (the red lines township grids), as
compared to the locations where I have actually found them on the
photos, are off by as much as 100 feet or more??????

I discovered that for Colorado Springs (at least) the new high res
color photos are way off the older B &W photos by a couple hundred
meters or more,,,,, I think it was Terra Server???? I sent them
an email and never got a response,, I don't live there, I have
friends there, so I haven't bothered to check if they have been
corrected???? Any reason to offset them for privacy, or security,
etc., would be laughable!!!!

I've noticed that Globexplorer does a good job of matching the high
res photos to the old B & W but the topos are still off?????? I
haven't worked with USAphotos for a while,,,, there are now hi res
color photos for my area,, I'll have to try USAphotos again,,,,,
(as mentioned by Frank Tabor)!!!
SKM

Karen Wheless

2007-08-19, 12:33 pm

On Sun, 19 Aug 2007 09:33:59 -0700, SKM-PSN#55 wrote:
> all of the web maps use UTM as their underlying master grid?????

May I ask ... is UTM what the Garmin StreetPilot III outputs (ie degrees +
minutes in decimal)?

SKM-PSN#55

2007-08-19, 3:33 pm

On Aug 19, 10:20 am, Karen Wheless <no_s...@airmail.net> wrote:
> On Sun, 19 Aug 2007 09:33:59 -0700, SKM-PSN#55 wrote:
>
> May I ask ... is UTM what the Garmin StreetPilot III outputs (ie degrees +
> minutes in decimal)?

UTM is a grid that is set to meters! They use Northing and
Easting! It is a very strange grid, until you get used to it, then
it is simple and very usable!

They divided the earth up into 60 slices, (called zones), starting
with the international date line, (or rather longitude 180) and
measuring east! Each zone is 6 degrees of longitude wide at the
equator, but everything is measured in meters and is measured as if
the earth were flat, so that as you go toward the poles, it doesn't
squeeze together like the longitude lines!

Now here is the part that messes up peoples minds! They set up the
zones so that they never work with negative numbers and all
measurements are made from the center longitude of each zone! Stay
with me!!! They assign the center grid of each zone as
500,000 anything west of that center grid will be less than
500,000 anything east of the center grid will be greater than
500,000

Now, each degree of longitude at the equator is about 111,110
meters three degrees from the center of the zone at the equator
is only about 333,330 meters (compared to the 500,000 at the
center), so you can see that even at the equator the zones overlap
big time! In theory, as you cross a zone the GPS will jump to the
new zone!! I've never hiked near the edge of a zone, so I'm not
sure how that would play out trying to estimate the distance to a
location in the next zone by visual estimate from your present
location, but setting that location as a goto location will give the
correct distance!

Even though the easting goes from zero to 1,000,000 for each zone,
they are really measuring a relative distance from the center grid!
In other words if you see an easting of 450,000 what you are
measuring is that the center grid of that zone is 50,000 meters east
of you,,,,, if you see an easting of 600,000 you are 100,000
meters east of the center grid!

For the northern hemisphere northing is easy,, it is meters from the
equator!!! For the southern hemisphere they offset the equator,,
the equator is northing 10,000,000 everything else is something
less???? Now, please remember that these are ellipsoid meters which
may or may not match the real world!!!! In other words the meters
you will read will be related to the datum that you set your GPS to,
not to real world meters!!!! Which for us hand held users doesn't
really matter, we're not into surveying and our readings will be
repeateable to the tollerences of our units,,, which works great for
geocaching etc. ha!!

You may understand this immediately ,or it may take a while,,,, it
took me several months to get it to a point that it became useful,,,
now I use it all the time!!! You can see the UTM tick marks on the
edges of USGS topo maps,,, those will be set to NAD27 datum,,,
most web maps are set to NAD83 or WGS84 some allow you to
choose!!! If you can choose units for your GPS it makes an
excellent converter,,, set your GPS to UTM and all your waypoints
will show up in UTM format!!!
Hope I haven't confused you too much, ha
SKM

Alan White

2007-08-20, 7:39 am

On Sun, 19 Aug 2007 10:20:46 -0700, Karen Wheless <no_spam@airmail.net>
wrote:

>
>May I ask ... is UTM what the Garmin StreetPilot III outputs (ie degrees +
>minutes in decimal)?

See
http://en.wikipedia.org/wiki/ Unive...e
_system
--
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.gt-britain.co.uk/weather

Jack Erbes

2007-08-20, 7:39 am

Karen Wheless wrote:
> How can I take the latitude/longitude provided by the Garmin StreetPilot
> III and plug it into Google maps to find the same location in the USA?
>
> For example, what do I plug into google maps when my StreetPilot III reads:
> N 32 49.230
> W 115 07.061

If you put that on one line like this, N 32 49.230 W 115 07.061, and
enter it into google maps for a search, it will find a location for you.
It found a place north of I-8 between El Centro, CA and Yuma, AZ.

On the find result, it changed the location from degrees and decimal
minutes to degrees, minutes, and seconds and it changed the north to a
positive value and west to a negative value. Like this:

+32° 49' 13.80", -115° 7' 3.66"

I think google will process about any lat/long format that is logical.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Jean H.

2007-08-20, 12:39 pm

Any reason to offset them for privacy, or security,
> etc., would be laughable!!!

Well, if each image has a random offset, it makes it a real pain for
anyone that want to copy and re-reference the images.
....

Jean

dold@22.usenet.us.com

2007-08-20, 3:42 pm

In sci.geo.satellite-nav Cooter <cooter@yahoo.com> wrote:
> FWIW, Google Earth is notorius for being off from known positions, and
> the amount varies from location to location. USAPhotoMaps is another
> application (free) that uses aerial photography, but it is black and
> white, and generally older images than Google. However, I have found it
> to be much more accurate.. I think the URL is www.jdmcox.com.

jdmcox has no data. It fetches from TerraServer, which is probably no
better or worse than other mapping data. In my area, the main highway is
off by about 250 feet, and gradually narrows to being correct as it gets
near town. Near a friend's house, the street is shifted about 150 feet
from one side of the intersection to the other.

I see this in TerraServer, Streets and Trips, and Street Atlas, but not
Google Earth or Google Maps.

At one location in San Jose, CA, the topo, BW and color photos are off by
500 feet from each other.

I typically find that Google Earth is as close as I can discern with the
granularity of the photo. but that is also true of TerraServer in most
places.

The big problem with Terraserver is that the underlying USGS topo maps are
horribly out of date in many areas of the country. My aerial photo is from
1993, the topo map from 1974. Google Earth is September 2005, and very
accurate.

--
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

_Pnina Gersten_

2007-08-21, 12:33 pm

On Mon, 20 Aug 2007 07:53:08 -0400, Jack Erbes wrote:
> I think google will process about any lat/long format that is logical.

Wikimedia will provide a dozen maps

http://tools.wikimedia.de/~magnus/g..._115_07_03.66_W

May I ask what you have buried at this interesting spot?

LinkBot