A Practise Traverse - Trimble & StarNet help.
I'm hoping someone could bestow some knowledge and experience on me. I did a practise traverse last night in preparation for a proper traverse I will be doing in a few days.
I drilled 3 x nails in the ground and called them CP100, CP200, CP300.
Using a Trimble S8 total station I measured a round of angles over each nail (starting with CP100, then CP200 and finally CP300) and exported the data in jxml and converted this file into a .dat file so that I could process the data in StarNet.
I was hoping someone could help me some questions about the traverse and the data I collected.
1) When using direction set data types in StarNet; am I correct in thinking that the At – From-To setting can be discarded as it has no impact on the adjustment (assuming that I am only using DB DN DM DE data types in the file)?
2) The setting I used for the co-ordinates in the Trimble controller was Easting-Northing-Elevation. However when I export the jxml file to a .dat file for StarNet I get the order to be Northing – Easting – does anyone know why this would be and has anyone else experienced this problem?
3) When I performed the traverse I used the settings (attached Pic 1) in the Trimble controller.
After downloading the data into starnet, I get the following:-
My question is this; I am trying to determine which sets of rounds relate to which Face the total station performed the observations.
I have commented in green what I believe which face the total station made the observations but I was wondering if someone could firm based on the Starnet data and the picture of the settings from the controller?
Any help will be greatly appreciated.
Did you use a StarNet converter to create that dat file or did you write it up yourself? The 18o° rotation should be accounted for on your face left observations.
The At-From-To setting should have no impact where At-From-To formatted data is not used.
Here is some directional data I collected yesterday. The sights are all F/R sets of observations
DM 1 0-00-00.00 241.5420 90-18-38.00 0.00/4.77
DM 1 0-00-12.00 241.5420 90-18-14.00 0.00/4.77
DM 1 359-59-53.00 241.5220 90-18-37.00 0.00/4.77
DM 1 0-00-01.00 241.5220 90-18-11.00 0.00/4.77
DM 115 120-34-27.00 67.6270 89-51-34.00 0.00/4.77
DM 115 120-34-39.00 67.6270 89-51-12.00 0.00/4.77
DM 115 120-34-49.00 67.6120 89-51-31.00 0.00/4.77
DM 115 120-34-58.00 67.6120 89-51-12.00 0.00/4.77
DM 410 177-50-10.00 37.3320 90-21-53.00 0.00/4.77
DM 410 177-50-18.00 37.3320 90-21-30.00 0.00/4.77
DM 410 177-52-13.00 37.3320 90-21-54.00 0.00/4.77
DM 410 177-52-17.00 37.3270 90-21-30.00 0.00/4.77
"Convention is like the shell to the chick, a protection till he is strong enough to break it through." Learned Hand
Thank you for your reply.
Did you use a StarNet converter to create that dat file or did you write it up yourself? - I used the converter to create the .dat file.
The 18o° rotation should be accounted for on your face left observations. - I'm not sure what you mean. I started the traverse with the T/S over CP100, I then backsighted to CP200 with an Azimuth of 0 Degrees. I then started the rounds and included CP300. After the round was completed I moved the T/S to CP200, I back sighted to CP100 and then started the rounds making sure that CP300 was added. I repeated this over CP300.
From the picture of the controller and the rounds from CP100 isn't there anyway of determining which obsverations were made on Face 1 and which were made on Face 2?
The At-From-To setting should have no impact where At-From-To formatted data is not used - That has helped clear some doubt.
Hi Steward, we are actually currently working through some known issues with the Trimble conversion. If you give us a call at 1-800-668-3312, or submit a ticket to the helpdesk here: http://helpdesk.microsurvey.com/index.php?/Tickets/Submit , our support team would be happy to help you with it.
Thank you for your input but I don't understand what you mean when you (and Norman) mean when you say that 180 is not accounted for???
In the screen shot below:-
I set up the T/S at CP100 and started my direction in Face 1 to CP200 and the CP300.
I did the same but in Face 2 so all of my vertical and horizontal angles should differ by 180 degrees which they more or less are?
In Face 1 at CP200 I got a vertical angle of 90-11-08.58 (shown in red) and in Face 2 at the same point I get 269-48-42.66.
So what exactly is incorrect?
I know my lack of surveying experience and knowledge is weak hence why I am asking "basic" questions.
None of the converters do Star*Net direction sets very well. In your data it looks like the converter is not subtracting 180 degrees from the Face 2 horizontal, nor is it subtracting the Face 2 zenith from 360. Star*Net wants all the horizontals and verticals in a direction set as if they were Face 1 observations.
It's difficult to entice new people into the profession without discussing proctology.
I think you have the Face1 Face2 figured out.
I withdraw my other comments. Seeing the ~270 degree values looked like the 180 hasn't been accounted for, and I was thinking about how the zenith angle was increasing from CP200 to CP300 in one case and decreasing in the other, but Star*Net should work just fine on your file, as the cosine of either angle will give the right sign for the change in elevation.
For azimuths, it doesn't matter what direction you start your set; Star*Net will just use the difference in directions.
When I look at your sample it looks right. This is a nice clean example of what you get when you ask for the "All observations" option in the JXL converter. It will write out each separate observation (although any observations that were explicitly stored as averages will be missing from the output. Watch for that and plan your field procedure accordingly)
The direction set HA values can be considered "Plate readings" or whatever the HA happened to be displaying when you observed that point. It could be an azimuth or it could be random, STAR*NET can accommodate both. As Bill93 notes, STAR*NET just uses the differences between the HA observations to compute angles. Then the direction set is treated as either a resection or a series of sideshots and backsights to one or multiple points, depending on the geometry.
Your example shows that the Face1 and Face2 observations from the same round are broken into 2 direction sets. This is intentional and allows the exact field observations to be used for the solution. The zenith angle in the 270 range mathematically reverses the HA so they will compute correctly.
B. Ed, Dipl. Geomatics