Would anyone be willing to look at a compass rule trav calculation? I can email it along. 18 Leg trav over rough terrain w poor closure. There's something funky going on, I think it's a blunder, but would appreciate a second opinion. Thanks in advance.
-V
Send It This Way
Also send it in a DWG format if you have it. It helps to look at it.
Question is why are you using the compass rule and in what program? Not all compass rule programs are mathematically the same, so that might be the hangup.
I have compared compass rule and adjusted compass rule programs against least squares and find then quite acceptable for a simple traverse. But today we seldom have a simple traverse, since it is so easy to add in GPS positioning or redundant observations. An traverse with the number of legs you have cries for multiple redundancies.
Paul in PA
Send It This Way
It's compass in LDD 2009. The site is thick, thick, thick so the trav just meanders the permiteter. Almost all the error is angular, and if I leave un-adjusted, the results match the monumentation better. The crew took redundant shots on monuments from different setups, but not on any trav points.
I'll send along. Thanks.
-V
email Is In My Profile
Redundant shots on monuments help, but only for 1 or 2 angles. But I do them.
The fact that unadjusted agrees better with the record, does the record close?
Save your 2009.dwg as 2004.dwg format. Raw traverse points are sufficient.
Did you use a different numbers on closing shots or did you force the original number? If you forced numers then I would need the angles and distance separately for those shots.
Did you carry elevations on your traverse points? You should as it reinforces that you have good closure. i.e. checking in within 0.1' on elevation but much farther off in N & E indicates an angle or distance problem.
Did you record a backsight distance check? As I said above maybe a distance problem. Backsight distance are especially important in rough terrain to check for any vertical/azimuth errors. You want your backsight elevation to be within 0.02' to show the azimuths angles are correct.
Lastly what is your instrument precision, backsight and foresight methods and number of D & R shots to properly set up a leats squares check?
Paul in PA
email Is In My Profile
The record does close, to 0.01'.
Typically to balance I renumber my last two points to the original #'s. I'll keep seperate in fbk file.
The crew did carry elevation and closed 0.08'.
They do check backsight distances and record in file, I went through line by line, all under 0.02'.
Nikon NPL 352 +/-(3+2ppm)
I cannot see an email in your profile. Maybe the problem is on my end. Sorry.
-V
If you have redundant observations then it would be beneficial to use Least Squares.
Least Squares can also help you find blunders. I would run it through StarNet but I left my software keys at the office.
What do you consider poor closure?
Click On The Envelope
In the profile or behind "Paul in PA" under the thread title. I am not sure if you can add attachments through the board. If not email me, I'll email you back and we are good to go.
Paul in PA
1:17000
The minimum standard is 1:15000 for Land Court here in MA. It's not the closure that troubles me, it's that adjusting out the angular error throws all the monuments out by .4' on one end of the traverse.
I think a leg settled out or something and the crew didnt catch it. I dont believe this was systematic.
-V
I'd be happy to look over the weekend. Did you use the perpendicular bisector method to attempt to find a busted angle?
I did, but the crew hasnt been back on site to deny/confirm it. We have aerial on the site, and they are going to have to ground-truth some spots, so I think I'll have them run a interior leg from one side of the trav to the other and see how that works out.
Thanks for the offer Don, I'll let you know.
-V
That's Thadd 🙂 He beat me to the response!! I figure you have enough eyes looking at it!
Don
Too Much Information For An Old Set Of Eyes
The field book used excess paper telling me things were good for the information supplied, but required information is not there. I am not familiar with bringing in an .fbk file to Carlson.
I have too many years with SMI raw data, where I immediately get to see what was shot in the field and decide if there is a lesser quality angle before it even gets to CAD. Plus SMI also gives a point file of what it shot. Since I see some angles to 1/2" I assume they are meaned but the raw foresight info is not there. I do see backsight D & R zenith angles but not D & R horizontal angles.
Your adjustment info indicates 18 sides when there are in fact 19 sides.
It appears I will have to sort out your traverse from the rest an input manually.
Paul in PA
HA, sorry guys, I get you Cape Cod boys mixed up.
-V
Too Much Information For An Old Set Of Eyes
I can send you a .RAW file if that helps.
Please dont put that much effort into it if you have to manually punch in angles/distances. I appreciate the help, but you dont have to work it out for me. I was just hoping something stood out as a red flag to anyone else.
Thanks again all.
-V
> HA, sorry guys, I get you Cape Cod boys mixed up.
>
> -V
It's the accent.
It Is A Rainy Afternoon, Today Was Set Aside For Hunting
So you think I want to get back on any of my own work? This is a chance to learn something. What is your data collector? Send me a raw file to look at. What then is the purpose of the fbk file?
Explain the adjustment report?
Paul in PA
:good:
I'd like to take a look at it- Please send me the raw file. and a pdf of the record, too-
A second set of eyes>>VH
Who you calling 'boy' son? Ever seen a boy pole vault out of bed in the morning? LOL
A second set of eyes>>VH
> Who you calling 'boy' son? Ever seen a boy pole vault out of bed in the morning? LOL
The accent and the lies that is.:-P
(actually, come to think of it, it's more likely that an 18-year-old boy would be pole-vaulting out of bed as opposed to an older guy's wishful thinking.)