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ISS-Transit tool

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Hi all, 


How accurate is this tool please if you've used it?  Is the time it gives for a transit the local time - i.e. if it says, say, 15:00 then it is 15:00 local time, no matter what time of year - i.e. no adding or subtracting one hour for BST etc?

Thanks in advance.


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Cheers Dave, yes I will do.  There are several transits of the sun and moon within a few miles of me over the next two weeks that I am going to have a go at.

What do you use to ascertain the exact time ready to hit capture?  Your mobile phone?

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Posted (edited)

There is a good - and free - app for iPhone called "Emerald Time" that shows time in HH:MM:SS which is what you need because need to know the seconds to start the capture 30s in advance.

After some research in the matter I discovered that the clock on an iPhone is accurate to within 1/20 of a second of actual time.  The Emerald Time app synchronises with NTP (Network Time Protocol) to four separate NTP servers on the Internet (that are accurate to within millionths of a second)and averages them out to give a very precise time - within a few hundredths of a second at your phone.  This gives a more than accurate enough time to know when to strart the capture.

I can't speak for Android but would suspect it is the same.


Edited by kirkster501
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