We would likely do a rapid static for that point. In the grand scheme we can usually obtain over 15 minutes of data while the corner accessory and note stuff is being done. When circumstances tell us there will be places with no radio we usually run 2 bases. One is an actual base with radio and the other is gathering static. This gives us sufficient baselines for a valid static solution. CORS and local private bases are our backup plan..
Yep, two bases, my base and a cors, but no need for very long occupations, I don't want to stand there for more than a couple of minutes 😉
> We would likely do a rapid static for that point. In the grand scheme we can usually obtain over 15 minutes of data while the corner accessory and note stuff is being done.
Yes, when you factor in all of the things that are usually done at a station, there is nearly invariably at least ten or fifteen minutes to log GPS data and get a baseline solution of excellent quality and high reliability. In rural work, the time needed to return to many locations to repeat and check a questionable solution is typically quite a bit more than the extra few minutes that a rapid static solution requires.
SW Section 32: from base; lt 49.25497", lg 39.61145", ht 46.41', from the cors pt; lt 49.25491", lg 39.61114", ht 4046.26'
S1/4 Section 34: base; lt 48.93168", lg 38.96637", ht 84.55' cors; lt 48.93193", lg 38.96656", ht 84.84'
the numbers are almost identical, the heights are not very good, not that I care much anyway, these aren't elevation points. I decided to use the base points as is, no need to adjust out the 2 to 3 hundredths.;-)
I will be monumenting the line soon and will get more redundancy on the points.
Our processes aren't about eaking out the last few hundredths or refining elevations that won't be published. It's about producing a reliable network in an efficient manner. The investment required to return a reliable position versus splitting hairs needlessly is a personal thing. I know what works in my circumstances, your milage may vary...
I'm the same way, I'm not to interested in a couple of hundredths, often I will use PPK cause it will return amazing results using short occupation times tied to far away Points. Of course starting a static session in PPK is the same thing as a session in static or fast static. For me it's about the redundancy.
> I'm the same way, I'm not to interested in a couple of hundredths, often I will use PPK cause it will return amazing results using short occupation times tied to far away Points.
Well, considering that Trimble specifies the PPK accuracy of the S8 at +/-8mm + 1ppm, over a 50 mile (80km) baseline that would be an uncertainty of more than about 9cm (=0.3 ft.). I don't think I'd want to rely upon getting 1cm accuracy on a 50 mile baseline except as a random event.
Hardly random, I do it all the time
> Hardly random, I do it all the time
You routinely try to get centimeter-level positions of survey markers from 10-minute or shorter PPK segments with the rover 50 miles from the base receiver or are you using the records from several surrounding CORS sites to create a virtual base?
No, not sub cm, look at the numbers above, the lt, lg's are quite good the h is not great, that is typical, had I spent more time in ppk it would have been better. Generally when I do these ties I'll see under 3cm or less than .1' xy. I've never seen more with a fixed solution.
> No, not sub cm, look at the numbers above, the lt, lg's are quite good the h is not great, that is typical [...]
Whenever I see decimeter errors in any component of a GPS-derived position, the first thing that occurs to me is that the baseline needs to be repeated since it looks like a bum integer fix.
In this case the cors derived point was just from the nearby cors, the h I will hold is from the base. The elevation for the base was adjusted between three cors and there will be some differences there with respect to h.
But this isn't an h job and the only thing the cors position is for is to check my base number