Can you help me interpret GPS EXIF data embedded in digital photos?

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates:
a) Decimal Minutes (GPS) : N37 49.19819 W122 28.71539
b) Decimal (WGS84) : 37.81997, -122.47859
c) Degrees Minutes Seconds : N 37° 49' 11.8914", W 122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Maybe the GPS guys know the answer?

On Wed, 10 Oct 2012 14:16:05 +0000, Simone D. wrote:

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates: a)
Decimal Minutes (GPS) : N37 49.19819 W122 28.71539 b) Decimal (WGS84) :
37.81997, -122.47859 c) Degrees Minutes Seconds : N 37° 49' 11.8914", W
122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

On 10/10/2012 15:16, Simone D. wrote:
Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates:
a) Decimal Minutes (GPS) : N37 49.19819 W122 28.71539
b) Decimal (WGS84) : 37.81997, -122.47859
c) Degrees Minutes Seconds : N 37° 49' 11.8914", W 122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Both my iPad3, Sony HX200V camera, and Huawei Ascend G300 phone save the
EXIF GPS data exactly as I would expect. How are you viewing the EXIF
data. I use GeoSetter, or PIE Studio, or the EXIF Viewer add-on for
Firefox. Can you put that image online so that we can check that EXIF
data with different programs?

One caveat is that immediately after switching on the GPS will not have
acquired a signal lock, and there should be /no/ GPS data recorded.
After some time, there will be less accurate data, and then within a few
metres. One other possibility is that the device is using Wi-Fi
location data instead of GPS data, and that location data is wrong.

Perhaps the device is remembering its last-used location?
--
Cheers,
David
Web: http://www.satsignal.eu

On 2012-10-10 07:16:05 -0700, "Simone D." said:

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates:
a) Decimal Minutes (GPS) : N37 49.19819 W122 28.71539
b) Decimal (WGS84) : 37.81997, -122.47859
c) Degrees Minutes Seconds : N 37° 49' 11.8914", W 122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Your assumption that both longitude & latitude should be saved is
correct, and the exif data should reflect that.

In the example you have given us you seem to have bad data, or at least
one or more tracking errors. I believe it would be fair to assume the
"E" in the Long. data represents "Error". Then the Lat. data just does
not make sense for the Golden Gate Bridge.

The GP-1 unit on my D300S gives the following data for a shot taken on
the bridge:

37°49'12" N 122°28'43" W
Alt: 185 ft.

As far as interpreting the data goes, your available software is going
to play a part.
I am using a Mac and as a simple viewer I use Apple's Preview, that
will show the GPS data and when clicking on the locate button, will
open Google Maps and indicate with the "green arrow" my position for
the shot. So below is a screen capture of the shot including the data
window, and how that is presented on Google Maps.
https://dl.dropbox.com/u/1295663/Fil...eenshot_31.jpg
https://dl.dropbox.com/u/1295663/Fil...enshot_32w.jpg

Then I also use Lightroom 4 which gives me the ability to map imbedded
GPS data, or to place untagged images on the map to add GPS data to the
EXIF. That gives me locations for a particular shoot.
https://dl.dropbox.com/u/1295663/Fil...enshot_30w.jpg

--
Regards,

Savageduck

On Wed, 10 Oct 2012 16:41:23 +0100, David Taylor wrote:

How are you viewing the EXIF data?

I'm using Linux "Eye of GNOME" version 2.30.0, File-Properties.

The funny thing is there is no Latitude either.
Is this normal from an iPhone photo?

On Wed, 10 Oct 2012 08:52:26 -0700, Savageduck wrote:

On 2012-10-10 07:16:05 -0700, "Simone D."
said:

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates: a)
Decimal Minutes (GPS) : N37 49.19819 W122 28.71539 b) Decimal (WGS84) :
37.81997, -122.47859 c) Degrees Minutes Seconds : N 37° 49' 11.8914", W
122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Your assumption that both longitude & latitude should be saved is
correct, and the exif data should reflect that.

In the example you have given us you seem to have bad data, or at least
one or more tracking errors. I believe it would be fair to assume the
"E" in the Long. data represents "Error". Then the Lat. data just does
not make sense for the Golden Gate Bridge.

The GP-1 unit on my D300S gives the following data for a shot taken on
the bridge:

37°49'12" N 122°28'43" W
Alt: 185 ft.

As far as interpreting the data goes, your available software is going
to play a part.
I am using a Mac and as a simple viewer I use Apple's Preview, that will
show the GPS data and when clicking on the locate button, will open
Google Maps and indicate with the "green arrow" my position for the
shot. So below is a screen capture of the shot including the data
window, and how that is presented on Google Maps.
https://dl.dropbox.com/u/1295663/Fil...eenshot_31.jpg
https://dl.dropbox.com/u/1295663/Fil...enshot_32w.jpg

Then I also use Lightroom 4 which gives me the ability to map imbedded
GPS data, or to place untagged images on the map to add GPS data to the
EXIF. That gives me locations for a particular shoot.
https://dl.dropbox.com/u/1295663/Fil...enshot_30w.jpg
I'm using Eye of Gnome on Linux.

I guess that's why the latitude doesn't show up in the iPhone photo
even though the longitude shows up but in a funny way?

Does anyone out there have GPS enabled on their iPhone to show what
it looks like on Linux?

On 2012-10-10 09:22:32 -0700, "Simone D." said:

On Wed, 10 Oct 2012 08:52:26 -0700, Savageduck wrote:

On 2012-10-10 07:16:05 -0700, "Simone D."
said:

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates: a)
Decimal Minutes (GPS) : N37 49.19819 W122 28.71539 b) Decimal (WGS84) :
37.81997, -122.47859 c) Degrees Minutes Seconds : N 37° 49' 11.8914", W
122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Your assumption that both longitude & latitude should be saved is
correct, and the exif data should reflect that.

In the example you have given us you seem to have bad data, or at least
one or more tracking errors. I believe it would be fair to assume the
"E" in the Long. data represents "Error". Then the Lat. data just does
not make sense for the Golden Gate Bridge.

The GP-1 unit on my D300S gives the following data for a shot taken on
the bridge:

37°49'12" N 122°28'43" W
Alt: 185 ft.

As far as interpreting the data goes, your available software is going
to play a part.
I am using a Mac and as a simple viewer I use Apple's Preview, that will
show the GPS data and when clicking on the locate button, will open
Google Maps and indicate with the "green arrow" my position for the
shot. So below is a screen capture of the shot including the data
window, and how that is presented on Google Maps.
https://dl.dropbox.com/u/1295663/Fil...eenshot_31.jpg
https://dl.dropbox.com/u/1295663/Fil...enshot_32w.jpg

Then I also use Lightroom 4 which gives me the ability to map imbedded
GPS data, or to place untagged images on the map to add GPS data to the
EXIF. That gives me locations for a particular shoot.
https://dl.dropbox.com/u/1295663/Fil...enshot_30w.jpg
I'm using Eye of Gnome on Linux.

I guess that's why the latitude doesn't show up in the iPhone photo
even though the longitude shows up but in a funny way?

Does anyone out there have GPS enabled on their iPhone to show what
it looks like on Linux?

I can't speak for Linux iPhone users, but I ask, is this an issue with
all your GPS enabled iPhone photos, or just the GGB shot?

Then there is the issue of obtaining a solid satellite fix vs a cell
tower triangulation, and a satellite+cell tower fix. Also to be
considered would be cell towers covering the GGB area, their ability to
triangulate, and the 3G/4G reception around the bridge. The thing to
remember is the iPhone is not a dedicated GPS unit, and it is quite
possible that there was interference created by the bridge structure
corrupting both satellite & cell tower fixes.


--
Regards,

Savageduck

On Wed, 10 Oct 2012 16:22:32 +0000, Simone D. wrote:

On Wed, 10 Oct 2012 08:52:26 -0700, Savageduck wrote:

On 2012-10-10 07:16:05 -0700, "Simone D."
said:

Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates: a)
Decimal Minutes (GPS) : N37 49.19819 W122 28.71539 b) Decimal (WGS84)
: 37.81997, -122.47859 c) Degrees Minutes Seconds : N 37° 49'
11.8914", W 122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF
data: GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

Your assumption that both longitude & latitude should be saved is
correct, and the exif data should reflect that.

In the example you have given us you seem to have bad data, or at least
one or more tracking errors. I believe it would be fair to assume the
"E" in the Long. data represents "Error". Then the Lat. data just does
not make sense for the Golden Gate Bridge.

The GP-1 unit on my D300S gives the following data for a shot taken on
the bridge:

37°49'12" N 122°28'43" W
Alt: 185 ft.

As far as interpreting the data goes, your available software is going
to play a part.
I am using a Mac and as a simple viewer I use Apple's Preview, that
will show the GPS data and when clicking on the locate button, will
open Google Maps and indicate with the "green arrow" my position for
the shot. So below is a screen capture of the shot including the data
window, and how that is presented on Google Maps.
https://dl.dropbox.com/u/1295663/Fil...eenshot_31.jpg
https://dl.dropbox.com/u/1295663/Fil...enshot_32w.jpg

Then I also use Lightroom 4 which gives me the ability to map imbedded
GPS data, or to place untagged images on the map to add GPS data to the
EXIF. That gives me locations for a particular shoot.
https://dl.dropbox.com/u/1295663/Fil...enshot_30w.jpg
I'm using Eye of Gnome on Linux.

I guess that's why the latitude doesn't show up in the iPhone photo even
though the longitude shows up but in a funny way?

Does anyone out there have GPS enabled on their iPhone to show what it
looks like on Linux?

Try exiv2, exif or exiftool

On Wed, 10 Oct 2012 09:45:59 -0700, Savageduck wrote:

I can't speak for Linux iPhone users, but I ask, is this an issue with
all your GPS enabled iPhone photos, or just the GGB shot?

I will check.

If someone else has an iPhone, can they just report what they see on
Linux default Eye of Gnome for the GPS settings?

For example, where is latitude?

On 2012.10.10 10:16 , Simone D. wrote:
Can you help me interpret GPS EXIF data embedded in digital photos?

I would have expected iPhone or Android phones to save both longitude
and latitude information - but the EXIF data doesn't seem to be that.

For example, the Golden Gate Bridge is at the GPS coordinates:
a) Decimal Minutes (GPS) : N37 49.19819 W122 28.71539
b) Decimal (WGS84) : 37.81997, -122.47859
c) Degrees Minutes Seconds : N 37° 49' 11.8914", W 122° 28' 42.9234"

But, none of these seem to align with the coordinates in the EXIF data:
GPSLongitudeRef = E
GPSLongitude = 51.00, 27.76, 0.00
GPSAltitudeRef = Sea Level
GPSAltituide = 24.00
GPSTimeStamp = 12:31:03:97
GPSImgDirectionRef = T
GPSImgDirection = 69.05

- Get exiftool to list the complete EXIF data of the file.

- Is that list complete? Did you leave out a section?

- Can you post the photo?

- Submit your photo to this site http://regex.info/exif.cgi and
see how it analyzes it and if the L/L is intact and at the right
place.

- What phone was that? OS?

- Before the photo was taken was the position correctly shown in the
map application on the phone?

- How did you generate that list? (Output from what app)?

From an iPhone 4, listed using exiftool (partial):

GPS Latitude Ref : North
GPS Longitude Ref : West
GPS Altitude : 25.04835165 m
GPS Time Stamp : 15:39:34
GPS Img Direction Ref : True North
GPS Img Direction : 75.1350365
other unrelated stuff for a few lines
GPS Latitude : 45 deg 37' 44.40" N
GPS Longitude : 73 deg 49' 28.80" W
GPS Position : 45 deg 37' 44.40" N, 73 deg 49' 28.80" W

--
"There were, unfortunately, no great principles on which parties
were divided – politics became a mere struggle for office."
-Sir John A. Macdonald