@gary_g Thats exactly what i have been doing so I can figure how the software works. Playing around with different settings etc.
Speaking of using CORS. What are Yall using for centering and height errors on CORS stations and are you processing linear quadratic etc.
If I'm doing an adjustment that's just bases and CORS I generally do something to the tune of 1-1.5mm for centering. If I'm doing a combined adjustment that includes RTK/stop-and-go, I'll usually bump it up to 3mm.
I usually process linear. There's usually plenty of stations within 5-15 miles.
@steinhoff gotcha. I am about where you are then. Do you see the lower factor first go so if i am remembering correctly lower means my measurements are better than I assumed. Higher I usually have an issue I didn’t catch. Or I thought i was better than I truly am. I use about 3mm for rtk . I am doing static to transfer elevation from a 1st order mark to site and cors to get my horizontal. We will also have rtk and digital levels as well. And a traverse through the woods. Cors stations are about 7 to 15 plus miles away some further for me to get one in each quadrant. Once i have a pair or two on site it will be smoother as a few miles total. Just getting it there. The bms are all within a couple miles so not bad to do what is required. I have to hold cors and at least one ngs main cors so fun times. Learning with tbc. I have not done a lot of post processing with it yet. Lots of other networks larger in the past but totally different software then. I asked the dealer how to disable spotty data on satellites he said no need. I am reading tonight to try and figure out if it’s possible. I used tgo years ago and i could do it there and same with gpsurvey for off the shelf software. I may run everything through opus projects as a check but client wants tbc reports so i will have to figure it out.
Do you see the lower factor first go so if i am remembering correctly lower means my measurements are better than I assumed.
Usually, yes. It'll be closer to unity if I'm doing CORS+bases & stop-and go together. Whether I process CORS baselines against the rover or just use baselines from my bases... depends on my mood and what kind of ephemeris I have. Distance and rover obs time is also a factor.
Higher I usually have an issue I didn’t catch. Or I thought i was better than I truly am.
That usually means a blown base height for me. This is why I highly recommend to crew to do somewhat significant changes in base heights between round 1 and round 2 of observations. 2 bases + different heights for each usually gives me enough to pick out the bad height.
We will also have rtk and digital levels as well. And a traverse through the woods.
A lot of networks I do are full combinations as well. If it's a rehash of an older project before my tenure I'll also usually scrape data from old control and topo files. Some of our chiefs still have it ingrained to do foresight checks when doing topo... Get enough of them together and you can actually get some decent redundancy when paired with the control work.
One fun thing to do if you can field 2 bases is have RTK vectors from your RTK base and post processed stop-and-go from the other base in your adjustment. Gives you a nice mix of processing methods for your GNSS to try to chase out the poltergeists.
I asked the dealer how to disable spotty data on satellites he said no need. I am reading tonight to try and figure out if it’s possible. I used tgo years ago and i could do it there and same with gpsurvey for off the shelf software.
The TBC equivalent you're thinking of is session editor. Select your baseline, right click, session editor. To be honest I somewhat agree with your dealer. From what I've seen TBC is pretty good about screening out the fuzz. There was a time when I checked all my baseline processing reports and then dived into session editor to turn off satellites or snip out cycle slips, but now I mainly do that only when stuff gets weird when the adjustment is happening and I'm trying to troubleshoot data.
@steinhoff Thanks that’s awesome information to know. I truly appreciate that information. Its funny. I have my crews do third point cks just because i know it gives me extra redundancy and it doesn’t take that long. I have been on smaller projects usually a boundary. Have them set up in the best spot in as close to middle of the site and rtk and logging. No cell coverage so network rtk is out. In these I usually have them set a few control points first thing then do all the mapping and and find corners. Rtk those observer control points. Then depending on time and how much mapping is still needed hit a couple of the main control again. Move base to one of those and finish up tying the prop corners and all control again. Usually the 3rd day i have them set base on one log data as a extra opus ck and any outliers tag again at a time i deem to get separation. Maybe. But its then they usually set up robot to locate bldgs car ports and items rtk don’t work. We have some decent traverse kits so they will usually measure rounds for any traverse needed to get into areas but they are learning fast to measure rounds to bs fs and known control point or prop corners we recently shot. And so they have slowly developed that eye for having ties and a good network pretty fast and identifying in the field now when something was bad and getting me that extra ck. At first it was a bit slower as they had to re think a bit but now they just abhave it down. My LS is still getting use to this as he has been a loop traverse guy and compass rule. So it has taken some time to prove to him how intergrating data and redundancy actually can be a better way a lot of times. The Trimble processor gives me an additional ck as well it takes no more time and such as well. So much power at our hands it’s amazing to me.
My LS is still getting use to this as he has been a loop traverse guy and compass rule.
I still see this a lot, and I'm not a fan personally. Does it work well enough for most people most of the time? Sure. Can't deny that.
Me? I want everything double determined at a minimum- be it from two different total station control points, total station + GNSS, or double occupied GNSS (although this probably isn't the case if we're working in downtown LA... can be hit and miss). 95/100 times you won't see much of a difference. 4/100 times you'll see a difference but it won't have a significant impact. It's that 1/100 that I try to account for when doing control- any type of control, really. You never know when you're recycling control/monuments to use in another project.
@steinhoff Is downtown LA Lower Alabama or Louisiana or Los Angeles. I appreciate the info. I have not done any stop n go since the USMC days. Glad you rattled my brain on that. I had not even considered that as an option. Might have to use that as my next training session. I am always trying to train on the options. So the crews have all the tools in the toolbox they might need. You just never know what situations might call for a different approach for sure.
Is downtown LA Lower Alabama or Louisiana or Los Angeles.
Downtown Los Angeles
I have not done any stop n go since the USMC days.
If our crews are running RTK then I have them use an RTK-logging style by default. Additional backcheck option (or in this case the opportunity to process your rover against an additional base) for free.
@steinhoff What epoch do you use at base and rover. I do the whole rtk and logging I remember that from the 90,s. A lot of what we do because of no cell is the whole opus. So i log at base for that while the map and do whatever so they can be productive. I will have to try the stop and go for sure. Today i am dealing with some very noisy data in static. Geezers its as if some of the cors station are taped to a dancer. To close to a military base I imagine.
What epoch do you use at base and rover.
Usually 1 second epochs. 10-15 degree elevation mask for RTK base and rover, 0 elevation mask for static. Now will the crew remember to make sure all constellations are enabled...? I dunno, but let's pray just in case.
@steinhoff nice. Why a 0 elevation mask at rover or is that a typo. And supposed to be 10. I have been burning the late night oil figuring out TBC baseline processor.i am so use to methodically processing sessions and independent dependent baselines it has taken some getting use to. I watched a couple partial videos on youtube and power hour. But nothing like the old days of telling the software exactly what and when you want to process. I did a all at once then manually chose some and I didn’t see much difference has the whole independent s dependent mine set gone away because technology has just become that good. Or does one still do this in todays off the shelf software. I been drawing circles and poly lines to mark them visually or am I missing anything that will mark them for me. And let me know i have process two baselines other than having to select them to see.
Why a 0 elevation mask at rover or is that a typo.
For a static-only base? I collect at 0 elevation mask and THEN process at 10-15 degrees. Why not? Plenty of storage space.
For something like an RTK base or an RTK rover? Yeah, 10-15 degrees like I noted above since you're working on the fly.
i am so use to methodically processing sessions and independent dependent baselines it has taken some getting use to.
Given that commercial programs like TBC utilize a baseline processor instead of a session processor like PAGES, all baselines are arguably independent.
@steinhoff I see the thinking in that. I have always never closed a triangle or loop at any common time frame as I built networks. I reckon if you have redundant observations it would show any blunders anyway. I have been playing around with both ways all everything and manually choosing and so far not a lot of difference. Hard to break old habits and how i was taught for sure. TBC is fairly fast time wise for sure. I will have to read up more on all of this for sure.
