## 2018-04-19 Notes

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 ™: 221.20400 = 0.553