igotu2gpx

Time synchronization

Asked by Inti Raymi

Thank you to share igotu2gpx.

Do you think that you implement the time synchronization in the version 0.4, also ?

Best regards,

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igotu2gpx Edit question
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Jakub Kowalski
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Michael Hofmann (mh21) said : 		#1

What kind of time synchronization?

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Inti Raymi (dominique-mesmaker) said : 		#2

The goal is to synchronise the GNSS data logger clock with the computer clock.

As you know, the camera and the GNSS data logger must be synchronised
to write the position in the exif.

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Michael Hofmann (mh21) said : 		#3

As far as I know is the time included in the GPS signal that is received by the tracker. Do your trackpoints contain wrong date/time information?

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Inti Raymi (dominique-mesmaker) said : 		#4

You are right, the time is included in the signal.
However, I do not know if the Igotu data logger has been programmed to synchonise
his internal clock with the time information of the signal.
Moreover, the data logger will certainly find his position easier and faster if the internal
frequency is correct initially. It's probably the reason why the first advice in the section
'How it works' (http://global.mobileaction.com/product/product_i-gotU_BT.jsp) is :
'Make sure your digital camera time is correct'.

Best regards,

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Best Jakub Kowalski (iss) said : 		#5

Actual time is included in GPS signal and internal clock (if there is any) is synchronized automatically. It has nothing to do with Time to First Fix.
Advice of setting correct camera time is for geotagging photos. You should set your camera clock to GPS time, so geotagging software can connect photos with correct trackpoint.

If you want to see GPS time you can use GPSd (https://answers.launchpad.net/igotu2gpx/+faq/493) and some GPS software like TangoGPS. GPS time is always UTC.
For setting correct time on your PC just use NTP (which should be as accurate as GPS time).

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Inti Raymi (dominique-mesmaker) said : 		#6

Thanks Jakub Kowalski, that solved my question.

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Michael Lush (mjlush) said : 		#7

Sometimes its not possible to accurately reset the camera clock in the field (say a very flat battery reset the clock)

One pragmatic solution for time sync could be to create an easily spotted event in the GPS track and simultaneously take a photo
Say put down three track marks within a couple of seconds and take a photo of the tracker (and if possible some googled mapped view).