Our company just recently within the last year got a GPS unit for surveying....
So far we have not had many issues that could not be figured out on our own until recently...
We were doing a topographic survey of a large fruit packing facility and we opened a few doors and placed the Rover just inside the door to get Finish Floor Elevations and recorded the shot like normal and continued on like normal. Later back at the office when making the map we noticed that the finish floor shots we took had about 2 foot of variation in elevation between them on a building that had a flat finish floor with no steps up or down.
We went back to the site, set up a level and checked from a benchmark and the finish floor was all the same level.
All of our other topog appeared to be correct as well. So it appears that the GPS rover errored (vertically only) when placed in and under a doorframe.. Has anyone else experienced this???
Also just to clarify when the shots were taken the rover reported fixed and not floating...
Replies
Thanks you for the input. seems that my operator was loosing his fix in the doorways (he didnt confess to this right away) so he would go out away from the door until he got a fix and then rush back in and take a quick shot before the gps unit could report a lost fix again. So i guess this fools the computer (data collector) into believing it had a good fix at the time of the topog shot. Needless to say we will not be trying this again....
I assume you are using RTK mode in for your survey. Are you able to achieve lock or did you lose lock when you are standing under the doorway?