Topcon GT distance issue
This is one I’ve never encountered, and I have a made and seen some crazy mistakes. I went over an hour away to do a “slam dunk” ALTA on less than an acre I surveyed five years ago. I had already done the difficult part and now had the chance to ground truth myself, which is never a bad thing. Topcon GT 503 robot with FC5000 running a fairly new version of magnet. I’m home now and didn’t remember to see what version. I setup the traverse to have multiple cross-over ties to give us lots of redundancy. I couldn’t get a 200′ tie better than 0.04′ and most around 0.08′. I also closed a loop around it. Had a total of 6 seconds (6 setups) in the angles. Linear was out 0.12′. No way that would meet the standards. We checked everything we could think of. Multiple times. All good. So I drove back very puzzled. Went in early this morning to make some minor edits to the raw data to run through SURVNET. I was hoping that it may point out something. I had the raw file edited and was about to save and close it when I noticed something. Every distance was to the nearest tenth of a foot. I went through the settings on the FC5000. All correct. Got the robot out to look at the settings and noticed that every manually triggered distance (no DC involved) was nearest tenth. Finally found the settings and fine mode resolution was 0.001, rapid was 0.005 and tracking 0.1. So as I see it, when the DC was set to tracking, the robot (because of its internal resolution setting) only output distances to the DC to the nearest tenth. Does this theory hold water? Did I or the other operator possibly fat finger something to cause this? Is it a glitch? I have been using the robot for a year with no issues of this sort. Rounding can’t be adjusted out so I’ll have to do it again. I still have scars on the backside from the chewing out I got in the days before surveying equipment had batteries… So I’m not green. I’ll also accept it if I fat fingered something to cause it. Thoughts?
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