Turning the screen brightness down solved my power problem -- I'm now getting through even long workdays with battery to spare.
The dealer offered to provide extra batteries -- at $3 per day each. If the screen brightness thing hadn't worked I was going to buy the car charger (not a battery bay, but the thing that plugs into the TSC7) for $255. I figure I could sell if for half that at the end of the project and be better off than renting extra batteries.
You could pick up an inverter much cheaper and just use that and the charger you currently have. I guess dealers do things differently all over. I had to rent gear often and always received a TSC7 with both the DC charger and cradle charger along with a couple extra batteries for TSC7. Now I always rented a base rover so I rented a cowbell extra for base. As most of the time I was renting it was for projects in no mans land so no cell coverage or very poor. You can place the dc in sleep mode with one push of power button it’s not turning it off in between drive times. Simply hit it again once at your point. Glad you are getting it done.
That’s a very common misconception of RTK observations. You are storing essentially a difference in position relative to your base station. It’s not raw data. Once your screen shown precision stop getting lower, continuing the observation is only wasted time and could degrade your position if you lose some satellite signals. If you are only using the collector and not TBC, you are better off taking 3 or 4 observations using the same point name and choose “store another “, then you can use cogo compute average and choose weighted average.
When I observe valuable points with RTK, I will go no more than 20 seconds, again seeing if precision shown has stopped decreasing. Just One RTK observation isn’t advisable. I’ve had points I observed 3-4 times that a point derivation report on that point in TBC showed the first observation as the worst being 0.05-7 off both H and V. Doesn’t happen a lot, but it does. And I reset satellite tracking between observations, fo not just turn your rod upside down. Consider RTK a resection where your control points are continually moving!
If prolonged RTK observations are worse than 180 epochs or 3 minutes and just taking several 20 second observations are better why does NGS recommend 5 minute observations? While I will agree that fewer epochs of data may point to tighter relative differences it does not prove that it is a better solution in the big picture. If I go to a point at 1200 and do a few back to back 20 second observations then got to another point and do the same 15 or 20 minutes later and then observe a third point and do the same. Then set up and turn angles and distances between them with a conventional total station I could see having decent results. Now you have a project where you are doing that around a site and now on opposite side of the site is now 3 to 4 hrs later I have always had better results with a minimum of 180 epochs or 3 minutes with two observations at a gap in time of 4 hrs making those points better relative to each other. I have heard the spill I don’t know how many times from a manufacturer that states 30 seconds is better and all that is needed even saw the math they had in a power point. The question I asked was this. Did you keep the same initialization or break it and were all three of those 30 second observations done back to back. Yes was the answer. I did a 2 1/2 acre Alta where we traversed and I shot all property corners and control with 4 rounds direct and reverse with good traverse kits and bipod on some of the property corners. Way over kill. This was with a 3 second S5. I was lucky as I could locate corners and control from across the site so many good cross ties. I went back did base and rover rtk r10 only. I located all the same points at 180 epochs and moved base and re observed each one. I moved it a third time. And did the same all 4 hr gap in time. Now two observations met the Alta specs but the third made the difference between conventional and rtk almost unbelievable so close it was not even funny. I tested direct distance and interior angles comparing the 2. Both vertical and horizontal positions diffences ended up in the reduced differences deltas in like a .015 ft horizontal and .024 ft vertical. This was a small site but I was trying to see if one could truly get to conventional type relative deltas on a small site. Both were adjusted via least squares. The two observations with rtk were an average.01 higher in both hz and vertical. Now if done like most the main traverse would have been direct and reverse through control only and side shots face 1 only to a poll on corners found. With no cross ties. When I compared those results RTK and conventional difference to corners saw .037 ft hz .05 vt. As the highest on a corner. Angles got a little higher diffence but in such short distance it was still negligible. All the same data set I just disabled observation in between each test. Most of this was done on my own time not companies. We were very close to the meridian and at the lambert parallel between zones all were done on grid.
You can take a 5 second shot and achieve the same results sometimes. Gps or GNSS rtk or static or ppk. Time in collecting and time in between observations are always good. Now to overkill like what I did is an also a trade off between what’s good enough vs what is to costly. For making money. If I were stamping something today I would require two observations minimum at 180 epochs with a minimum of 2 hrs but prefer 3 to 4 hrs. If those results exceeded the minimum standards I would roll with it. Of course what does project requirements need to be met etc. I actually have done rtk with three for vertical with digital levels and have dad tremendous results that far exceeded manufacturer specs in the diffences in heights with those procedures.
"If prolonged RTK observations are worse than 180 epochs or 3 minutes and
just taking several 20 second observations are better why does NGS
recommend 5 minute observations?"
Perhaps they made such a recommendation at one time but I'm not sure that is the current thinking. Check out the recommendations on pgs 42-44 of the following document:
https://www.ngs.noaa.gov/PUBS_LIB/NGSRealTimeUserGuidelines.v2.1.pdf
Redundant 3 minute sessions are their top level recommendations. They put a lot more stress on PDOP management and multipath reduction than they do on time of occupation.
BTW - that whole document is a must read for every RTK user, IMO.
Yes it’s a great document and when it was written it absolutely had focused on just GPS. They are working on the new guidelines I would imagine. Possibly that will change some things for sure. All I know is after years of orbits and years of geodetic work. Things have changed some with how manufactures develop the algorithms to establish the positions in an RTK environment. However no one manufacture follows the guidelines or guidance 100% in what is recommended via the government that established and set up the messaging and why each recommendation should be followed. I for one firmly believe that you can obtain great results in shorter occupation times. But across the board and to achieve the highest possible best solution it makes no sense why shorter is better. It makes no basic sense in GNSS whatsoever. So many things outside of the norms of what most look at like multipath etc that can go wrong with satellites themselves. Things happen all the time and end users never even are aware. The common terms that use to be stated was well it was just an anomaly. Well maybe but When you have watched a satellite for years orbiting and tracking that you get a perspective that’s is much different than a result we see on the user end. I would still say 3 minutes is a drop in the bucket for seeing this on the ground.
"Perhaps they made such a recommendation at one time but I’m not sure that is the current thinking."
Current thinking is reflected in the draft NOS NGS 92, which requires 3 each 5-minute NRTK observations, or 5 each 5-minute SRTK observations, for a 3 cm vertical (EH) project like the one I'm doing. RTK observations must be separated by at least 3 hours and span at least 2 days, and each NRTK group (i.e. emanating from a given PRS base) must have at least one OPUS-S validation session.
There are also post-processed options, but all require longer sessions.
@jhframe since you are doing this to go in OPUS Projects. I know for static it is highly recommended to orient the antenna correctly as opus projects and opus now use the absolute antenna calibration files. Were there any recommendations when doing rtk with the GVS files in doing this.
Trimble HD-GNSS & ProPoint
Windows Screen brightness is number one power draw on TSC7 followed by WIFI. Settings on rental gear may be set to "check for updates", turn that off for sure. There are bad TSC7 batteries circulating out there as well. I can get 8 hours on 2 with suspend mode engaged (screen off) between shots and BT engaged the entire time with R12i's.
"Were there any recommendations when doing rtk with the GVS files in doing this."
I don't recall whether or not antenna orientation is explicitly mentioned anywhere in the draft NGS 92 documents, but correct orientation is fundamental to the process so I can't imagine not adhering to it.
And related to what some have mentioned earlier about occupation time, here's a quote from one of the Trimble documents that were linked above:
"For establishing survey control points, Trimble still recommends that the user occupy each point for 3 minutes, and then again for another 3 minutes at least 2 hours later with a significantly different satellite constellation." I assume that NGS testing indicated that a longer occupation time was warranted for projects to be included in the IDB, thus the 5-minute spec.
"I know for static it is highly recommended to orient the antenna correctly as opus projects and opus now use the absolute antenna calibration files. Were there any recommendations when doing rtk with the GVS files in doing this."
I don't recall if there's any mention of antenna orientation in the draft NGS 92 documents, but correct orientation is just good field procedure so there's no excuse for not doing it.
And with regard to what some expressed earlier about occupation time, I note that one of the Trimble documents linked above states:
"For establishing survey control points, Trimble still recommends that the user occupy each point for 3 minutes, and then again for another 3 minutes at least 2 hours later with a significantly different satellite constellation." I expect that the NGS testing indicated that a longer observation period was warranted for marks to be incorporated into the IDB.
I might respond on to that, but use paragraphs because that is unreadable.
That’s probably the case. Remember, NGS only uses US satellites so they aren’t dealing with the real world now. I saw a recent surveyor article or post from an instructor who said he doesn’t use a RTK initialization unless it’s been fixed for 15-20 MINUTES! People living in 1998 aren’t working with all 4 constellations and Galileo and Beidou have changed the RTK game!
NGS has some really good presentations on the proposed NGS NOS 92 standards.
I saw a recent surveyor article or post from an instructor who said he doesn’t use a RTK initialization unless it’s been fixed for 15-20 MINUTES!
That's pretty funny...It takes less time than that to converge for a PPK solution...if we followed that protocol we'd never get any work done.
Remember, NGS only uses US satellites so they aren’t dealing with the real world now.
There's already multi-GNSS support for certain beta products, and the new standards and specifications are being written with it in mind.
