Hi Guys,
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I have done a link traverse adjustment using Bowditch in Excel but the results does not make any sense. I may be wrong. I have attached the file. Can you kindly help to check it out.
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Cheers
Neda
I do not see the beginning coordinates in your spreadsheet.
other than that, simply looking at the values in the Bearing field, the traverse does not appear to be closed back to the beginning.?ÿ I see that all the "bearings" are in the northwest quadrant except for the final leg, which is going to the northeast, if I am interpreting your data as you intend.?ÿ There seems to be a missing call or calls, or you were closing on a second point for which you had known coordinates.
You definitely can't do this kind of adjustment without making it a closed loop or specifying a second set of given coordinates.?ÿ
Why is there a station ISUN9 with no values?
The beginning coordinates are on the Constants sheet.?ÿ Not sure why they aren't entered on the main worksheet.?ÿ It seems strange that the northing is for LP2 which is a station ID but the easting is for 'A' whatever that is.
The column heading should be labeled DMS not DSM.?ÿ By the terminology I'm familiar with, those are azimuths, not bearings.?ÿ Bearings are usually (at least in older work) given within a quadrant such as N 12 34 56 E.?ÿ How did you get these values??ÿ
If using a theodolite or total station you measure angles, and have to compute azimuths or bearings. Those numbers might make more sense as angles left or angles right.
I find it strange that measured distances are computed by the scale factor from grid distances, which is opposite of normal.?ÿ Which did you measure or were given or to start with?
I JUST WASTED 6 SHEETS OF PAPER PRINTING OUT THE SPREAD SHEET!
Makes no sense. Plus, why in modern work are we converting to links?
Paul in PA
I JUST WASTED 6 SHEETS OF PAPER PRINTING OUT THE SPREAD SHEET!
Makes no sense. Plus, why in modern work are we converting to links?
Paul in PA
You should not have printed it out.
A clear explanation of the Bowditch method is provided here:
https://engineering.purdue.edu/~asm215/topics/travcalc.html
Note that the method is frequently employed subjectively and does not provide information for statistical analysis like the method of least squares.
Doing a web search on the method implemented in a spreadsheet shows a number of YouTube videos.?ÿ
As for the method of least squares, see?ÿ http://www.personal.psu.edu/cdg3/free.htm for some free software including one performing adjustments. The site ??Free Goodies? was developed by Dr. Charles Ghilani now Professor emeritus at Penn State U-Wilkes-Barre. His Adjustment Computations text is widely used in US surveying programs. ?ÿ
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