Edit 2008-05-29, On google maps:
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Sunday, May 25, 2008
Friday, May 23, 2008
Downloading tracklog files from MIO C220 GPS
MIO C220 GPS does not allow you to download the tracklogs. A very small change to a data file is required to enable the transfer of the tracklog gpx files. This webpage describes how to download the GPX files from MIO C220 in detail: Link (Worked for me without a problem.)
Monday, May 19, 2008
Geo Tagging
I have a lot of photos most of which have time stamps. But it is more useful to have a 'geo-stamp' , that is, a location stamp for the photo. Most cameras (atleast until now) do not have GPS chips. But there is a very simple automated method to get geo stamps.
All that you need is any camera and a very simple GPS unit (need not have any fancy map or anything).
Set the time on camera:
Before you go and shoot pictures make sure that you set the time of your camera very accurately (to within seconds). Setting the time on the camera accurately is the key for geo-tagging this way. Time is the only common parameter for the photos taken and the GPS track logs. So if the time is off then the lattitude and longitude will also be off based on how fast you were moving at the time of taking the picture.
GPS Receiver track log:
Switch on your GPS receiver and start recording your track. Most GPS units automatically record in either GPX or NMEA formats. Either is fine.
Take as many pictures you want but be sure to carry the GPS along with you (in your pocket or bag at all the times).
After you have taken all the pictures, you now need to use a software called gPicSync (a free open source software which can be downloaded here: http://sourceforge.net/project/showfiles.php?group_id=191804)
Step by step:
- Download and install the gPicSync.
- Open gPicSync.
- Select the folder in which your photos are located.
- Select the the folder in which the GPS track is located.
- Set the time offset: You would have set the time on the camera to local time. But the GPS records all the time in UTC (GMT). So the program would have to know what is the difference between your time and UTC. For San Francisco it is -7 (when day light saving time is on). For India it would be +5.5.
- Voila! you are all done ! All your pictures now have a the latitude and longitude information in the EXIF data. If you upload them to picasaweb or flickr, they can be shown on a map with no effort at all!
- See some of the pictures taken using my mobile phone on maps here: Photos on Picasa and Photos on Flickr
Sunday, May 18, 2008
Converting GPX to KML files
GPX files are the most common format used for GPS tracklog files. But Google Earth accepts only KML files. Hence the need for a converter. I found this software called GPS Babel which converts GPX files to KML Files.
Here is a step by step instruction for converting GPX to KML:
- Download the GPS babel zip file from http://www.gpsbabel.org/download.html
- Extract the zip file to a folder.
- Open the file GPSBabelGUI.exe.
- I used the following settings:
- Click on "Let's go"
- You should now see the following text in the message window
- gpsbabel.exe -p "" -w -r -t -i gpx -f "C:\TEMP DEL\Track saved on 2007-07-29 15_18_24.gpx" -o kml -F "C:\TEMP DEL\Track saved on 2007-07-29 15_18_24.kml"
- And then:
- Now you are ready to use the KML file. You can double click on the KML file that was just created to see the track log in Google Earth !
In my next post, I will probably list the steps that I followed to extract the track logs from my MIO C220 GPS to my computer.
