I am facing various challenges during the preparation of this ride so I have started a puzzles section to see if I can get some help. The first puzzle to solve will require a Navigator with Excel skills >more
Comments
[Posted with Joe's permission by SB - if you want a copy of Joe's spreadsheet just ask by posting a comment]
The attached file ***might** be a start for excel, I have no way to validate it other than via your bike computer (see below)
Formula found on the web, wasnt sure it was right at first but the total mileage as calculated is pretty close to your bike computer so I think it probably is correct.
A few notes;
The mileage agrees with your bike computer, give or take (12.23 miles GPS vs 12.75 bike). You will find GPS consistently underreads compared to the bike, mine certainly did as well, mainly because the bike follows every little deviation and the GPS does straight lines between points plus there is inherently more error in the GPS....of course, that depends how your computer is set up, did you measure the distance between marks whilst sitting on the bike when you calibrated it?
It seems you can get more accurate distance calculations by taking the curvature of the earth into account which this calc doesnt, however at the distances we are talking about here, the difference is supposed to be less than 0.25% so not worth worrying about. If you cycle to Patagonia you can change the formula!
Hope this helps and my formula isnt completely cockeyed but just happens to work through a fluke, I dont pretend to understand it, its 100% plagiarised!
[Posted with Joe's permission by SB - if you want a copy of Joe's spreadsheet just ask by posting a comment]
The attached file ***might** be a start for excel, I have no way to validate it other than via your bike computer (see below)
Formula found on the web, wasnt sure it was right at first but the total mileage as calculated is pretty close to your bike computer so I think it probably is correct.
A few notes;
The mileage agrees with your bike computer, give or take (12.23 miles GPS vs 12.75 bike). You will find GPS consistently underreads compared to the bike, mine certainly did as well, mainly because the bike follows every little deviation and the GPS does straight lines between points plus there is inherently more error in the GPS....of course, that depends how your computer is set up, did you measure the distance between marks whilst sitting on the bike when you calibrated it?
It seems you can get more accurate distance calculations by taking the curvature of the earth into account which this calc doesnt, however at the distances we are talking about here, the difference is supposed to be less than 0.25% so not worth worrying about. If you cycle to Patagonia you can change the formula!
Hope this helps and my formula isnt completely cockeyed but just happens to work through a fluke, I dont pretend to understand it, its 100% plagiarised!
Joe
Posted by: Joe | May 12, 2006 at 07:42 PM