Lately was asked about DiNi and robot height difference in this forum. I am having similar problem, but between the laser beam and mini prism/360 degree prism using the same instrument - Leica TS16. Target is a sticker on the wall.?ÿ
What I exactly did...
I oriented my total station using the pole (height 2.0m - I remeasured it with tape measure) and 360 degree prism. Points were on the ground. I controlled the height after orientation. Everything was perfect. Then I measured the wall targets. After that, I decided to use the mini prism to do the rough control (didn't look for the millimeter) for my wall targets. I checked the mini prism height on the point what I used for the orientation.?ÿ The height difference what I got was 2 cm for the wall target which was ~40m away. The wall target which was ~150m from the total station showed 4cm difference when I did the laser beam vs mini prism check. I had one more point ~160m away from the total station showing the difference 2 cm. So, I wouldn't say the further the worse.
I did the adjustment for the total station, still getting these results.?ÿ
Any ideas? Experience? I know that using different methods - prisms and laser can give some difference, but 2-4cm is a lot. Is it possible to get so big difference with laser beam between two targets. When transferring height from one target to another in one stand. I did put the total station cross in the center of the target manually. Should I just stop doing the control with prism as it's incorrect?
Work gives interesting research ideas every now and then :)?ÿ
?ÿ
?ÿ
If I read this correctly, you are all set up using the 360, everything is good, then you use one of your sticky targets and the reflectorless as a new backsight, and stake to your original control point with the mini prism, and discover the verticals are out somehow? Is the mini prism also a Leica part or is it a mix and match? Are you changing the reflector setting in the instrument or the DC when you do this? What is the HT of your mini prism?
?ÿ
Mini prism GMP111 is being used and I changed the reflector settings for sure. Mini prism height was 10 cm.
Hey,
Im not quite sure what you trying to say. Try to be more specific.
Are you checking sticker target heights with GMP111 backspike or what?
Few possibilites/ideas that can cause differences in elevation:
-Using only 1 face measurements. Though 2cm is a lot at 160m even if your instrument is way out of calibration.
-Steep angles when you orientate with 360 prism and ground targets.
-Wrong prism constant with steep vertical angle.
-Using ATR on stickers.
-Vertical compensator is somehow turned off.
?ÿ
Most propable id say is human error, only one face measurement, compensator off.
?ÿ
The NEZ of the retro reflective targets on the wall exists on the wall.
If you want to check or improve them; measure them directly.
I suggest you go into a shaded place, perhaps someplace tranquil, and set up a number of trials to examine different approaches to measuring angle and distance. Set up a tripod over a point and shoot with ATR/Lock and manual at different angles, do the same to a block of wood, have your partner try to transfer height or line using the 360 only etc. Use a plumb bob and sight card, on the same point, measure it with a tape, plumb bob and mini, with tracking without, glancing, angle offset, trialed HD offsets etc.?ÿ
This suggestion is not to explore anything on the research level just to help you develop a practical understanding of the equipment and approach.?ÿ
Holding a 360 prism, loose off the rod up to the side of a wall trying to check a sticky target on the wall is folly.?ÿ
?ÿ
?ÿ
?ÿ
?ÿ
?ÿ
Mini prism GMP111 is being used and I changed the reflector settings for sure. Mini prism height was 10 cm.
OK guessing the error is from the 360 then. From my experience on a 1203 with ATR, if you are closer than about 200 feet, if the prism is not properly oriented (the little arrow on top facing the instrument), the ATR can grab one of the lower prism faces and now your set up is about 0.06' off in vertical. Would never use a 360 to set control. 360 prisms should be kept locked away until the crew understands this.
Try doing it over with the mini prism for your setup point. If someone gave you control done with short sights on a 360 you may have to chase out where they compounded the error
