imagej tool: https://imagej.nih.gov/ij/index.html example article: https://imagej.nih.gov/ij/docs/pdfs/examples.pdf
downloaded satellite photo from google maps. 200m zoom. which is settable in the url. https://www.google.com/maps/@37.4845179,-122.2345346,200m/data=!3m1!1e3
Set the scale by measuring the legend. set the length and units.
draw the diameter of the turn. command+m.
sequoia hs track measurements diameter 234.6ft straight 310.7ft
circumference = pi * d = 737.02 turn distance = circumference / 2 = 737.02 / 2 = 368.51
1 foot = .3048 meters
turn = 368.51ft = 112.32 m straight = 310.7ft = 94.70 m 2(112.32+94.70) = 414.04 m
400m track. 414.04 = 3.5% error
acceptable error pct for submission.
diameter 231.78 231
don’t measure the straightaway. deduce it. we know the sombitch is 400m long.
take three measurements. use the median (throw out the high and low). then back out the straightaway distances.
sequoia hs track. 231 feet diameter. pi * d = pi * 231 = 725.71 turn distance = 725.71 / 2 = 362.85 ft 362.85 * .3048 = 110.60 m turns length = 110.60 * 2 = 221.20 m straightaway length = 400 - 221.20 = 178.80 178.80 / 2 = 89.4m per straightaway.
turn factor ™: 221.20⁄400 = 0.553