Capt.Mooron wrote:
The link seems to get blocked....

That's a shame, it's an interesting gizmo.


... anyway if two GPS Recievers are
comunicating data you effectively have replicated " 2 waypoints"... or
"movement"..... after that it's a matter of calcs. I was referencing a
single GPS Reciever.


Sure, but you didn't *say* that.


There is a similar suitcase-sized instrument for surveyors, but I can't
find a link to one.


There are several types. again it's remote receivers communicating with the
base unit. A single receiver can NOT give you bearing without alternate
input.

Agreed.
Unless it's moving, in which case it "looks backwards" and uses those
pesky calculations again to derive heading.



That's a fact Doug. Deal with it. :-)


I have, many times.
Deal with it!

BTW- don't let my years of experience in Total Station and GPS Survey curb
your opinion of my statements! :-)

Not at all. You made an incorrect statement, probably an oversight by
not being quite technical enough. It's OK, nobody expects you to write a
book on how GPS works, and all the things it can (or can't) do, for the
benefit of a cretin like Bubbles/bitty-bill.

You are aware of course that climatic conditions affect accuracy on GPS
Survey Receivers.

Of course. It's a radio receiver, after all.

... You cannot get better than centimetre vertical accuracy on
dynamic receivers

Is that with optimum constellation geometry? I should think some of the
fancy wave interpolation antennae units could do better than that, but I
don't know (they're a bit out of my field & price range).

... and Static Collectors are left for hours to download and
average data.


You can do that with a small hand held too, if you've the patience for it.

DSK