I don't like to break the record, but of course sometimes it's necessary to show record vs measured on a plat. The last one I did had a section line of record that I surveyed in 2010. Resurveyed it for a BLA.?ÿ
I put it into the drawing and drew the line with the new locations and slapped a bearing/distance on it. One thing that can get me into trouble is having old and new points in a job. I try to always separate them with layers.?ÿ
Well this time I had a bearing of S89-31-37W, distance of 2651.42' between the section and 1/4 monuments for record and S89-31-36W, 2651.42' for measured.?ÿ
I didn't believe it so I looked through the TBC and C3D files and sure enough it's correct. Record is 2651.424, measured is 2651.416, the one second is where the "error" is. This was using 4700/5800 combo's 10 years ago compared with R10's today. I guess we have our bubbles adjusted.?ÿ
Wow!?ÿ Just wow!
Its common. Modern tools are pretty good.
(Why didn't you just whack the monument with that 6lb sledge, to make measurements agree)
????
A few years back I established a small control network for a nearby city and ran duplicate 1-hour static sessions on the stations using Trimble 4000SSi receivers and 2-meter fixed-height tripods.?ÿ A few months later I needed to use a couple of them about 1/2 mile apart to reset a 1/4 corner, so I set up a regular round Leica prism over one and a total station (Leica TCRA1102plus or GeoMax Zoom 80, don't remember which one) over the other.?ÿ When I shot the backsight distance I was dismayed to see a discrepancy of 0.06' from my own record distance.?ÿ Then I remembered that I had the data collector configured for Leica mini-prisms, so I changed the BS prism setting to Leica round and reshot the backsight.?ÿ The discrepancy dropped to 0.006'.?ÿ Close enough for me!