ISS-Transit tool

[kirkster501]

Hi all, 

https://transit-finder.com

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.

 

[Laurin Dave]

Hi Steve

I used it once to grab this  ISS crossing the Sun today at 10:28 - Observing - Solar - Stargazers Lounge

As far as I could tell it was bang on time local time (ie BST as it was April),  but just in case set the camera going 30s before..

Dave

[kirkster501]

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?

[Laurin Dave]

I used this  Current Local Time in London, England, United Kingdom (timeanddate.com)

[kirkster501]

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 June 11, 2021 by kirkster501