GPS Query

[Waxing_Gibbous (Peter)]

OK.
I like GPS - very useful in my car.
But is it really any benefit to a scope?
Even if you are going off to the middle of nowhere, you can look up the co-ordinates before you go.
I mean just about everything I own will tell me to within a couple of hundred meters where I am (Telephone, i-Whatsits, Tom-Tom, Laptop etc.).
Do I really need to fork out the extra hundred or so dollars for a dedicated unit for a mount?
Does it make the mount more accurate than simply entering the co-ordinates manually?
Will the mount 'forget' where it is without one?
Given that I can input co-ordinates faster than it takes a GPS unit to lock-on (if at all), aren't they, well frankly, a bit of a waste of money?

[mithrandir (Andrew)]

Originally Posted by Waxing_Gibbous

Given that I can input co-ordinates faster than it takes a GPS unit to lock-on (if at all), aren't they, well frankly, a bit of a waste of money?

As long as you don't make typos and remember whether it wants DD/MM/YYYY or MM/DD/YYYY or YYYY/MM/DD and time in UTC or local with allowance for DST, maybe. It's not very amusing when you get the date/time wrong and it slews off in the wrong direction.

Mine feeds the mount the location and the UTC time. I put the tripod together, attach the Gemini, GPS and power cable and by the time I'm ready to turn the Gemini on I have a fix.

[frolinmod]

If you're using something like TheSkyX, then you do want to know and enter your location within several arc seconds as well as your time within a second or so. The more accurate the better. As you say, that is easily achievable via many different means. Looking up the location on Google Earth in advance is a good one. Many remote and not so remote locations don't have cellphone signal coverage. A GPS receiver is just one convenient means.

I use a Garmin GPS-18x LVC with 1PPS output to both determine my location to within several meters and to synchronize my laptop's time to UTC within a millisecond. It's way overkill, but there's no Internet service for time synchronization and no cellphone coverage in most of the places where I set up.

For real overkill, if I really want to know a location accurately I use a u-blox LEA-6T GPS receiver with a geodetic antenna and fixed height tripod I bought on Ebay, collect RAW observations for a few hours and later postprocess them against a nearby CORS or SOPAC reference site. That tells me where I was within a several millimeters. Good enough to follow the local plate tectonic motion when observed over long periods of time (~30mm/year to the Northwest)!

[Waxing_Gibbous (Peter)]

Andrew - I'm not the sharpest knife on the rack, but for some reason I manage to get dates and times pretty much spot on and I check my tYpinf before entering. Also, push comes to shove, I can use a Sextant (4 years in the Navy boy? - You BETTER know how to use one ).

Ernie - Blimey!
You're not getting lost in a hurry!
30mm a year?
You'll be able to walk to Spain soon.

[Grimmeister (Anthony)]

Hi Peter,

I wouldn't buy one specifically but did obtain one as a part of larger purchase I made and despite it being a luxury it is nice to not have to think about the little deatils and let the GPS unit do it for you.

Would I buy one No, would I own one Yes..

cheers

Anthony

[traveller (Bo)]

Got a GPS for my Nexstar 8SE, thinking it might be useful when going camping etc. Just waiting for the clouds to go away, wind to settle down, temp to rise up a little...