Rod height always required, and busted often when not attached to fixed rods or any length.
And who the hell came up with the brilliant idea of taking a 2m rod, and adding that useless option of 1.8m?
I spent my whole life, well, last 10-11 years using a 2m rod, and now half the time I'm a few points in and see that whoever used the equipment before me did theirs on 1.8m
Any time I see data that conflicts about 0.6-0.7', I just shake my head and wonder if they had the rod right
@jph?ÿ
We have the misfortune to have a number of poles designed and marked for the Trimble MT1000 prism.
Set one of those poles to 2m and the actual top is at 1.865m - the MT1000 being 135mm from base to centre of glass.
I'm sort of used to it now and always work with true heights - but our young guys often get a 135mm bust between GPS and Total Station work.
@jimcox?ÿ
Direct-read prism poles are a double-edged sword, but only if you have crews that aren't paying attention. All Trimble pole prisms have a 0.135m height from bottom to glass centre, so it's not like they have too much to keep track of, and it's a big enough difference that a bad backsight or CP check will immediately be apparent.
Our crews each have a prism pole and a 2m snap-lock GNSS pole.
Although my general preference is to have poles with measurements only to the bottom of the threads so that I can do the math myself and everything is consistent, it ain't that difficult to say "The prism pole is for the prism. The GNSS pole is for the rover. Don't mix them up." They look nothing alike, yet crews still somehow screw it up.
The pole should come with, or you should have a shop make, a 5/8-11 extension 0.135 m long so either that prism or the extension and the antenna is always used.
@bill93?ÿ
One of my (expletive deleted) bosses tried that - but the adapters that were made not 135, but were designed for the R10 so long as you changed the default measure point from 'bottom of quick release' to 'antenna base' - which just adds to the confusion. Plus they are heavy and adversely affect the balance of the pole.
I would MUCH rather have poles that are correctly marked.
If I had my way we would ditch the special ones, and just add a simple value (which can be measured in the field) for whichever prism I am using
like this?
??Adapter for Trimble VX & S Series 360 Prism, so prism is at Trimble Standard target height (135mm)?
@dmyhill?ÿ
Is there any literature that backs up your statement, or is it just based on experience?
NGSRealTimeUserGuidelines.v2.1.pdf
https://www.ngs.noaa.gov/PUBS_LIB/NGSRealTimeUserGuidelines.v2.1.pdf
?ÿ
That statement is technically true but a bit subjective IMO. An increase in epochs logged will increase the instances of signal differencing available to resolve the baseline.
As session time decreases, and especially as site conditions worsen, logging at shorter intervals can improve results significantly, and in some cases, help you obtain a fixed baseline solution where you might not have gotten one with a longer interval.
However, if you are following best practices and your station location has good sky, and you are logging for typical static times i.e., 20 minutes or more, it likely won't make that much difference in the final processed baseline. A 1-second interval will make resolution of the baseline easier, but not change that final position much.
I don't mind logging at 1 sec because our current equipment has plenty of memory and, just as critically, the state reference stations that I process against are logging at one second as well. If your base stations aren't at the same rate there's no advantage. I will also sometimes push the boundaries of what is considered "good satellite visibility" in remote areas and want to squeeze everything I can out of that observation. Since it doesn't cost me anything to do so, it's not an issue.
But back when I had older gear with very limited memory, I would calculate how fast I could afford to log based upon the observation schedule for the day, and then bump it up to the next highest regular interval to ensure I wouldn't run out of space mid-observation...
@rover83?ÿ
I have questions concerning what kind of solution to use. My two choices (MAGNET Field) are single baseline (SBL) or multiple reference stations (MRS). We use a subscription network from Lengemann ( https://www.lengemann.us/l-netftpdatasite.aspx).
(1) Does SBL mean you're using your own, onsite base station?
(2) Should you switch between SBL and MRS when you're having trouble getting a fixed solution? I was told, by Lengemann, not to switch between the two on the same job. Can you explain their reasoning? Do you agree, or disagree with them?
(3) Does the User Guidelines for Single Base Real Time GNSS Positioning?ÿ(NGS) apply equally to the network that I use?
That statement is technically true but a bit subjective IMO.
It is a "rule of thumb", not an exact scientific statement.?ÿ?ÿ
One thing I didn't see mentioned yet, is the use of occupation planning software.?ÿ You can use this to predict when the satellite geometry will be optimal at a given location, or to predict when satellite coverage will be spotty.?ÿ This is less of a concern when we have so many satellites to look at these days.?ÿ You can also use this software to determine how much satellite constellation and position changes over time.?ÿ A few minutes with your favorite occupation planning software might be very educational for you.?ÿ Below is a web address to Trimbles site...
https://www.gnssplanningonline.com/#/settings
HTH
@learner?ÿ
Topcon MAGNET Field has mission planning software, which we never use. How about a website like https://www.spaceweatherlive.com/en/solar-activity.html to plan around increased solar activity?
