Lat/Long v GOTO accuracy

[DrRobin]

Hi,

Just been wondering, if I am 1 arc minute out on my Lat/Long, does that mean that my GOTO accuracy will also be 1 arc minute out?  Or, do the errors get calibrated out when doing a three star?

Or put another way how accurate does Lat/Long and time make a difference for GOTO accuracy?

My Canon/C11 combination is only 27x18 arc minutes, so do I need to be 10x more accurate than this?  I know that it is relatively easy to look on Google Earth and get to within an arc minute or so (provided it is accurate) or use a GPS, but how much difference does it really make?

Same with time, I can get Internet time, accurate to less than 1 second, but there is much more than 1 second uncertainty when setting time on a handset, so I don't normally both too much about the seconds.  Is this a mistake?

Anyone with any experience?

Robin

[jambouk]

I suspect the issues the handset will have if you enter the wrong coordinates and/or time is what it thinks is above the horizon and what it thinks is below, so I don't think it will make your GOTO inaccurate (assuming you do an accurate star alignment), it will just not want to GOTO objects in its database which it then thinks are below the horizon.

There are various free apps for phones which tell you your coordinates and the time.

The other issue about the time, is if you are planning to park the scope and turn it off, then re-start it up and give it just the time and it will remember where everything should be.

James