Hello,
I'm attempting to write an excel program that will calculate the midpoints in a sectional breakdown. I believe the distance by known coordinates and the associated angular calc could be used. Does anyone know of an existing program or written code, any suggestions would be appreciated.?ÿ
Thank you,
Paul
Will this exclude Sections 1-7,18,19,30 and 31?
Edit:?ÿ One must consider the procedure varies for setting the center corner based on the years each set of Instructions were used.
It has been my experience that the mathematical center of a section is never the true center of a section.?ÿ More often than not, a monument has been ignored, an offset monument has been accepted as an actual corner, or the original field notes and surveying instructions have never been consulted when someone is trying to do a mathematical breakdown of a section.?ÿ Disaster for everyone!!!
Don't be one of the dreaded expert measurers and rapid stakeout hitmen.?ÿ Surveying is the art of following those that came before you and the science of locating the evidence so the survey can be mapped and perpetuated for generations to come.
My $0.02, for what its worth....
Shouldn't the methods in "Restoration of Lost and Obliterated Corners" be used?
I think some of us are forgetting that sometimes we are the first to break down a section.
It is also sometimes usefull to know how far off the corner is.?ÿ
This would be a simple program once you decide what the inputs are, except that accounting for curvature on the e-w cl may be difficult in Excell.?ÿ
I do it in ordinary Cogo software. My choice is Microsurvey.
There's an old program by the BLM called "All Points" that calculates section breakdowns in State Plane coordinates based on protracted values.?ÿ If you can find that (it was DOS app) you could study the code.?ÿ
I do it in ordinary Cogo software. My choice is Microsurvey.
Is microsurvey capable of geodetic calculations?
@aliquot no. I just assume the world is flat when subdividing a Section.
I started doing most lost corner search coordinates and breakdowns with lat and long quite a while back. It was amazing how much closer it got me to real corner locations. There are a lot of things in the ground that will never be found staring at a calculator...
I started doing most lost corner search coordinates and breakdowns with lat and long quite a while back.
How would that differ from using SPCs?
@field-dog I am on true bearings and convergence is accounted for without any thought.
State plane isn't either surface distances or true bearings. Surveying using true bearings and surface distances is proper in the PLSS. It used to be more time consuming, but with modern programs it's not a big deal. Basically if you want to prorate a 1/4 simply mean the lats and longs and there's the answer. For an east-west line you will find the SP bearings will show a kink at the 1/4. Really important I assume in AK, less so in FL.
?ÿ
It was mentioned sometimes we are the first to break down a section. My experience is that may happen once or twice in a career. In most cases the section was broken down by the holders of the patents to the quarter or half sections 150 years ago. Hardly any patents went to one owner for the entire section in this state.?ÿ
BLM, in Alaska 100% and I believe most of the other State offices use Geodetic COGO programs with automated theoretical township breakdown to the sub-section level.?ÿ ?ÿThis is helpful for "skelontized townships" without prior sections being surveyed.?ÿ ?ÿAs pointed out by many here, sections with prior surveys and controlling corners are computed with geodetic COGO using Manual or State procedures based on the source of law that applies.?ÿ Be very careful doing computations on a State Plane or other grid when true bearings need to be used such as single bearing tree tie, double proportion etc.?ÿ ?ÿI have an Excel Spreadsheet that is public domain that uses geodetic positions for found controlling corners and record distances for single or double proportion computations.?ÿ ?ÿ ?ÿ So if you have surveyed with GNSS and have latitude / longitude values for controlling corners, it computes the proportionate?ÿ position on the arc.?ÿ ?ÿI am out at my cabin in the bush now for the rest of the week so do not have it with me, but can make it available on a later post if?ÿ anyone is interested in having a copy.?ÿ ?ÿ
