Total Station check on Triumph LS control
- Thread starter Adam
- Start date
Nate The Surveyor
Well-Known Member
What Jim is seeing, is the same thing I see, when going into the abyss. (Abyss, is a valley, covered with tall pines, and other obstructions).
Quite simply, it is where the obstructions, and the and satellite configuration are coinciding. Back in my L1 days, these sites could be gotten, with mission planning. In our modern times, with the Javad, another shot later in the day, when the Sats have moved, he could get it with LOWER RMS.
This equipment is STILL a statistical measurement system, and subject to all the things that interfere. So, if this were an important shot, then do it 3x.
I like to think in terms of a good camera, with adjustable exposure. When all things are very still, you could set the camera to a LONG exposure time. Well, setting the LS to a 3 minute exposure, and it "Gets it" but has higher RMS than desired, it simply means "This is the best I could get, during this particular 3 minute window". Shoot it 3x more, at differing times, and then use the AVERAGE function. (I am sure Jim is probably AHEAD of me on all this) but the AVERAGE function typically will ALSO weed out the higher RMS shot, and will generate an average shot, that is CLOSER to the ones with smaller RMS. I have been playing with this very thing.... Remember, I try to BREAK things like this, and find it's weak points.
I will also add, when a shot generates a "string cluster", where the 180 seconds of data shows a string of dots, with not alot of clustering, those are often poor shots. I had one of these string shots, recently, 180 seconds, and re shot it... the final coord was some 0.085' from the "String shot".
Some of what I am writing is my "Impressions" from a USER point of view. Somebody more technically oriented could probably say all this in a "more better way". (That's a southern way to say better!)
Carry on...
N
Quite simply, it is where the obstructions, and the and satellite configuration are coinciding. Back in my L1 days, these sites could be gotten, with mission planning. In our modern times, with the Javad, another shot later in the day, when the Sats have moved, he could get it with LOWER RMS.
This equipment is STILL a statistical measurement system, and subject to all the things that interfere. So, if this were an important shot, then do it 3x.
I like to think in terms of a good camera, with adjustable exposure. When all things are very still, you could set the camera to a LONG exposure time. Well, setting the LS to a 3 minute exposure, and it "Gets it" but has higher RMS than desired, it simply means "This is the best I could get, during this particular 3 minute window". Shoot it 3x more, at differing times, and then use the AVERAGE function. (I am sure Jim is probably AHEAD of me on all this) but the AVERAGE function typically will ALSO weed out the higher RMS shot, and will generate an average shot, that is CLOSER to the ones with smaller RMS. I have been playing with this very thing.... Remember, I try to BREAK things like this, and find it's weak points.
I will also add, when a shot generates a "string cluster", where the 180 seconds of data shows a string of dots, with not alot of clustering, those are often poor shots. I had one of these string shots, recently, 180 seconds, and re shot it... the final coord was some 0.085' from the "String shot".
Some of what I am writing is my "Impressions" from a USER point of view. Somebody more technically oriented could probably say all this in a "more better way". (That's a southern way to say better!)
Carry on...
N
That helps, Jim. Thanks for taking the time to post the pics of locations. I can see those sites resulting in those sorts of residuals. I'd probably do repeat observations to squeeze as more accuracy from those sorts of places. Of course, I'm sure you felt it wasn't really necessary since you were running the conventional network too. Just out of curiosity, how are the vector exports working for you. Happy?
Wes Cole
Active Member
A couple days ago one of my P.C.'s, Alex, set two control points with the LS & RTN and started a waterline topo up a mountain subdivision road. Today he made it to the top and tied in his last point in the open with the LS/RTN. Here's the text I got from him:
"Just tied into my RTK point up top. Can't believe these results!"
11 is his traverse point, L11 is his LS/RTN point. Total traverse was around 1500', and about 200' in elevation gain.
"Just tied into my RTK point up top. Can't believe these results!"
11 is his traverse point, L11 is his LS/RTN point. Total traverse was around 1500', and about 200' in elevation gain.
Wes Cole
Active Member
It's a nice check, especially for waterline topo.