Calling John Hamilton, Loyal, and the other static gurus

Kris,

I don't have (or want) TBC, but if you want to shoot me the RINEX (.dat T01) file for your base, I will play around with it in OPUS (and TEQC), and see what I see. I can't even formulate a booboo scenario that would equate to 8ft.x12ft. of difference.

LDOGEO at AOL dot COM
Loyal

Just to check the basics, in TBC you checked the GEOID model and such to make sure they are correct? I've used TBC to post process and it gave me a great solution, however I did end up removing some CORS stations as they were giving me grief....perhaps one of the reports can shed light on why so sloppy?

Kris
I have barely used TBC so I am a loooong way from being proficient with it but I wonder if you used the position imbeded in the CORS rinex file rather than the published position in the datum compatible with your base? I don't imagine that is the problem but sometimes simple little things like that go unnoticed.
I don't consider myself a static guru but just thought I would toss my 2 cents in.

John

GOOD point John

That could very easily return the kind variance that Kris is reporting, and about the only thing that would.

Loyal

Check the CORS-Base vectors

A real easy check on whether or not TBC is screwing something ELSE up (probably user error), would be to CHECK (compare) the actual vectors returned by TBS and OPUS.

The OPUS vectors are in the G-FILES (extended output) and look like this:

G-FILES 
                                           
Axx2011 129  11 129
B2011 1291519  11 1291936 1 page5 v1009.28IGS     226 1 2 27NGS   2011 131IFDDFX
Iant_info.003        NGS   20110124
C00090001-1270484525   14  643294460   20  101523539   16 X0291A4430X0291AGOSH
D  1  2   992546  1  3 -3879357  2  3 -8124172
 
Axx2011 129  11 129
B2011 1291519  11 1291936 1 page5 v1009.28IGS     226 1 2 27NGS   2011 131IFDDFX
Iant_info.003        NGS   20110124
C00090002  252899449   10  875436521   24 1033458073   21 X0291A4430X0291AP057
D  1  2  8909142  1  3 -3511956  2  3 -2208022
 
Axx2011 129  11 129
B2011 1291519  11 1291936 1 page5 v1009.28IGS     226 1 2 27NGS   2011 131IFDDFX
Iant_info.003        NGS   20110124
C00090003  207878819   15   17319756   16  107369116   18 X0291A4430X0291AP086
D  1  2  4792177  1  3  -574245  2  3 -7958156

I don't know what the TBC vectors look like, or where to find them, but they are there somewhere. The two sets of vectors SHOULD agree at the centimeter level or better.

Loyal

John

How would I know? I imported the rinex file from the ufcors site for the day and time of the base data. I really had no idea. I wonder if I just import the whole zipped folder instead of the rinex only, kinda like the picture and not the world file.

Thanks! I'll try this tomorrow. On the ones that worked, I imported the zip file and it stripped what it didn't like and it worked great!

John

Kris
After you import the rinex file into TBC and before you do any processing, check the position of the CORS point against the published values for the datum your base is in.
John

If you want to send it to me, I can run it through TBC myself.

Johns and Loyal

Okay, so I suspected that when I imported on the rinex, it didn't have the right value. So, I imported all of the files and let TBC kick out what it didn't like. I then compared the values coming in (LLH) with that of the published CORS stations. They were exact. Okay, so then I process the values again. No dice.

Then, I said, self, why don't you set the CORS stations as fixed, so I figured out (lord only knows how) to change the quality of the point to control, which when I was done, only changed the icon on the screen to a triangle from a circle, but when I went back to check, still said unknown quality.

There has got to be a way that I can tell this godforsaken software that the CORS are right, and I want to know what the value of this other damn station is. Alas, I haven't found it yet.

In my best Airplane voice "I picked a helluva week to quit drinking!"

This sucks. I got an OPUS solution on this point that all the stats say is GRRRRREAT! TBC can't or won't process the files.

Loyal, check yer male bro!

Kris

Got'em downloaded already!

I'll try and play with this stuff tonight (depending on the afternoon beer consumption), and I'll for sure run the whole shoot'n match through both OPUS and Waypoint GrafNav (tonight or in the morning).

BTW, the Oatmeal Stout is finished cooking @ Suds Brother's Brewery, and if Nate gets his butt in gear today, we should be enjoying it this afternoon.

:beer:
Loyal

Kris

I,ve had the same problem when I tried to change a point's quality. If I get a weekend to go over all the help menus and such I may figure it out; but from what I'm reading it isn't making sense to me. In TGO it was simple, in TBC the point quality seems to get fixed and no amount of clicking on the point will change it. How I got around that: when I have processed a point that was unknown but came in as control quality is to process the baselines and then go to adjust and fix the cors points and then run an adjustment. It worked but I didn't like it.

Kris

That is also an issue that is not real clear to me yet-changing the quality. It seems if you want to enter an ortho height it HAS to be grid, I never work with grid coordinates-I just deliver grid.

I am slowly learning. I couldn't figure out how to select multiple baselines with the mouse-you have to turn on the mouse toolbar, and then make sure that select with left mouse is enabled.

Alright boys, check this out

So, I figured out what my problem was. First, there is a VERY COOL utility in TBC that will go to the UFCORS site and pull in the data for the points you're trying to process. You must first have your data loaded either via dat file or d/l. This utility also brings in the data sheets for the CORS sites. When this utility is used, it forces the CORS sites to be named control points and not unknown quality. This save about 5 minutes of clicking.

So, I had an OPUS solution from the other day, (I'll get to the first one in a minute), and OPUS said the NAD83 (CORS96) Epoch 2002.0, Geoid 03 values were N=10,591,002.707, E=3,947,874.841 and a Z of 391.006. I went and pulled the same CORS stations in for the day submitted.

John and others, you'll like this. Under view, go to project explorer (or toggle f9). When I load data from the dat file, it comes in as a control point. This was where I couldn't get past before since my processor was holding my base fixed, and processing the damn CORS stations backwards from a here position (no freaking wonder right?!?). So, the CORS need to be control, and the point doesn't, simple I know. Under project explorer, click on your point to process. It will open a second editor (PITA I know) then you change the GRID, LOCAL, and GPS positions to mapping, or surveying, or whatever, something other than control. The icon should change around the point like it would in TGO (yippiee something that is still the same!).

For John, now I've got three baselines from my CORS right? So click one, hold the control button, and then click the other two. It will process only those baselines. Slick huh!?

So, after I did all this above, I came up with the following
N=1,591,002.71828
E=3,947,874.86909
Z=391.715

The Z concerns me greatly. It's 7 tenths higher. I'll work on figuring that one out. However, the other is 0.0113 and 0.028 different. Plenty damn close to connect to the NSRS if OPUS is down.

Loyal, this one is for you. I feel like (so correct me if I'm wrong) that OPUS does WAY more behind the scenes than we know. In fact, I think it takes CRAP data at times and comes up with answers that we really wouldn't use normally. I found this on my first one when I got it to process. It wouldn't process to two of the CORS as it FAILED and was only a float. I looked at the data from the CORS for that time and my base, and the CORS data was clunky to say the least from two of the CORS. Is this why you work with CORS and not OPUS routinely?

At any rate, I feel MUCH better about a lot of this stuff. I'm still much behind the curve than the rest in this static discussion. When you guys start talking static, I listen. Short L1 baselines from a known point are pretty easy. This handling CORS data and working with it, can be tricky and the vertical thingy isn't giving me the warm and fuzzies.

But, I can say that I feel much better about No. 1, knowing how to do this, and No. 2, that my software is comparing to OPUS close enough for me and most of the rest of the surveying world.

Thanks for all the help, if I learn something new, I'll pass it along with this program.

TBC has a few REALLY COOL features, that I wish they would have put in TGO, but they didn't, so I'm still learning, right? 🙂

Loyal

Drink a few for me brother!!!!!! Sounds very tasty!

Thanks for the help!

Alright boys, check this out

Is it an R8 GNSS receiver? There is a problem with OPUS right now when using that receiver. Something like 0.14 m height error if I recall correctly. I don't know if they have fixed that problem, or are even aware of it.

Alright boys, check this out

As a matter of fact, it is an R8 GNSS receiver. So what you're saying is that the CORS may be spot on and OPUS off? That's scary when you think about how many of those receivers are out there and how much that utility is used.

I'm actually digging using the CORS stations and evaluating the CORS data like I would my own for short baselines. For whatever reason, I guess I thought that all CORS and OPUS were perfect. I hate to admit I may have been wrong, especially on a Friday at beer thirty, but what the hell! 🙂

Alright boys, check this out

What is scary is that most don't seem to notice. I have mentioned it to several people, and sent an email quite a while ago. It has to do with the antenna model. Curiously, OPUS-RS gives a warning message, but the results are not in error.

That is why I process my own stuff, more control over it.

Alright boys, check this out

With a little more practice, I may be right there with you. Also, for static shots that I would normally process from my base station only, now I have the other three to 7 vectors (depending on the CORS stations used) that I can use to tighten them up with.

I feel like I just got a new toy and I've been using this gear for years.

And that my friend, is the epiphany of the day that should scare you more than anything. How many others like myself have not taken the necessary steps to figure this other out. For the guys that run L1 only gear, they probably have, but us lazy dual frequency folks with OPUS at our fingertips haven't.

As for the reports, thank GOD I took stats in college! 🙂

Thanks man, and have a great weekend!

Alright boys, check this out

Kris
I only have a demo copy of TBC so I'm not very proficient with it but the way I change a point to the level of control is to click the little add coordinate icon at the top right of the points properties box when you have the point in question highlighted. Then simply drop down and change the status. The add coordinate looks like a survey target with a plus sign.

Sorry I wasn't able to join the discussion earlier but I was away from my computer.

John