Single and Double Proportioning – decimal latitude and longitude
I single proportioned along a Township line (between T46 & 47N, R1W, M.D.M.) using decimal latitude and longitude. This is using a 1983 Record of Survey. This is not the final answer, just a way to create some search coordinates. The R/S set the northwest corner of T46N, R1W by double proportion, set a monument. It found the northeast corner of Section 4, so there is 2 intermediate Section corners.
The R/S is tied into NAD27 control so I used NCAT to get NAD27 latitudes and longitudes. I proportioned the latitudes and longitudes (the corners are not at precisely the same latitude). It seems to have worked. My inversed distances along the township line match his calculated values and he set corners on the latitudinal line in R2W, my bearing breaks match his. Also some offset checks match the numbers in the BLM Standard Field Tables.
There are bunch more Section corners I would like to DP in this way (not the final answer). I’m thinking SP the latitudes for the northings and SP the longitudes for the eastings. It would save me from having to convert everything to true bearings. I think it will work.
Some of my coordinates (mainly in the northeast quadrant of the township) are estimated by computing old Records of Survey then finding some link to a known NAD27 coordinate. One from 1959 has a solar basis of bearings so I rotated it by the convergence angle to grid, it looks really good in Google Earth. The central meridian of the zone goes right through my work area so the convergence angles are small, at most a few minutes. A 1973 R/S is about 11′ off, I have no idea what he was doing (no Basis of Bearings statement) but when I rotate it to the 1959 R/S it matches at about 1 foot from a coordinate I generated from 1952 Division of Highways field notes which had ties to triangulation stations. This is a couple of miles from the 1959 survey so I took that as very reasonable.
Note that Meiss Lake has probably been moved east 2 miles. I’m pretty sure the 1856 Deputy was not off 2 miles. The water level is a couple feet higher than the ground in Sections 3 &4. I don’t know how the 1983 surveyor DP’d Monument 3 since the GLO deputy did not survey across the top of Sections 3 & 4 due to it being Tule Swamp. I tried 3 different versions of calculated record distances. Just assuming 80 chains across the top of 3 and 4 comes the closest to his answer but not exactly (0.05 in northing & 1.03 in easting). 1983 R/S excerpt:
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