The attached PDF is a white paper I wrote on how to verify a modern, year 2000+, GPS resurvey of the mining claims. The resurvey was however was a partial resurvey. Some of the claim corners were resurveyed using GPS, but the late 1800's survey was very good. The other edges of the claim parcels could be re-plotted from the old patent plats.
I wrote some code for QGIS 2.18 for bearings and calculated a distance from the US BLMs GLO shapefiles. By running the calculation scripts, I could compare the "new" bearing-distance" with a georef'fed PNG of the claim survey plat. The calculations were also run on the tie lines to the Mineral Location Markers.
The biggest "gotcha" is getting the angle between the map quadrangles lat-long lines and the UTM coordinate lines. The angle is available for the center of a topo sheet in the lower left hand corner. That is the "Grid north rotation factor" discussed in Notes and or Problems number 2.
At the time this code did what I wanted it to do. There are problems with rounding such as "N 15-60 W" being reformatted to "N 16-0 W".
If the attachment gets stripped please email below and I will reply. Hope this helps. J.O. Williams j . o . williams . jow @@@ gmail . com
Re-Survey-Workflow.pdf
Description: Adobe PDF document
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