I always stay in grid except for a couple of exceptions.
1. A remote forest boundary, buried deep under 200 foot tall trees, no GNSS, over 8 miles of traversing around or through 2 sections with 2 cross traverses. That had to be processed in a local ground system.
2. Our terrestrial Lidar point cloud software (Leica Cyclone) doesn't know what a map projection is. It produces point clouds in scale factor=1.000 only. So my solution is to scale my control up to ground at a convenient central control point and feed the control coordinates to Cyclone that way. I usually am able to register my scans together autonomously because the Leica P50 scanner is surprisingly close to total station quality then have it do a nested registration where it ?ÿessentially does a best fit of the scan control points to the modified SPC of the same?ÿcontrol points. In a perfect world the scan data would be processed in SPC but Cyclone doesn't have that capability.
Lidar Scanning & Cyclone was invented by electrical engineers so the jargon is different and they have no idea about map projections and scale factors. The early scanners couldn't even be leveled. One time I did a boundary for an electrical engineer, he wanted it because the neighbor built the fence way off on the neighbor's side (the opposite of what we are used to). I tried to give him station & offset, he was totally baffled, couldn't understand it at all. Probably does calculus in his sleep but can't add up a column of numbers.
Great examples.
In the case of scans, if I were asked to do a scan, I'd probably end up taking a selfie and if I were asked to analyze a scan, I'd just go to bed for a week and hope that it went away.
That said, does this indicate that you could enter your control in xyz coordinates and get them back the same way?
http://www.sage.unsw.edu.au/sites/sage/files/u112/3.%20Geo-ref2.pdf
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Would it be correct to assume that to work always in grid, the CSF would have to be applied one way, to tie into control, and the other way (reciprocal of) to layout? Is that what Magnet is automatically doing?
Does it give you the option of specifying that you are laying out a ground distance or grid distance?
If you work in grid but are ultimately laying out ground distances, then it seems that would have to be the case.
Thanks.
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I appreciate very much how this conversation is going overall. No harsh words or hurt feelings. ?ÿA good and helpful chat amongst fellow peers.
When working on grid with a tape or edm the distances must adjusted. The EDM distance is ground distance.?ÿ Magnet always stores the raw ground distance then applies the CSF to create the grid coordinate. When you do a Setup the computed CSF is computed and displayed. The user can change it. This works well when using a single co troller with EDM and RTK. I get excellent quality checks between both.?ÿ
Run a few checks. If you have two static gps run a long session and post process yourself, no OPUS. Inverse the grid coordinates.?ÿ Now set up your edm with controller set to SPC. Measure distance and the controller should apply the CSF.
Thanks - I guess what's confusing me is -?ÿ in your system, if I was in stake out line and entered 0+56 as my desired station, would I be laying out a point 56 ground units away from station 0+00, or 56 grid units away from station 0+00??ÿ
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Thete is No layout on?ÿ ground, system. ALL stationing and inverse are on grid when in SPC. Basically when in SPC every thing is on grid. It is seemless conversion. Even though your EDM measures ground, all your computed data is on grid.?ÿ
If I run all the scans on control points I could import grid coordinates then put each scan setup on its control point individually. Grid to ground differences between adjacent control points are usually very small.
Trimble is integrating everything in TBC so that scan data is processed just like any other data. They have the right idea with their SX10 which can measure to a prism like any total station, faster and more accurate. But it isn??t as fast or capable as a dedicated scanner.
Leica scanners still require a paddle target which is a flat circular plate with white fallout shelter target over black. The scanner fine scans the target and determines the center of the target. It would be great if their scanners could turn sets to a prism. They do backsight in both faces then collect targets in both faces but they aren??t turning sets.
