Farsite mode: match the mbedward/farsite reference

Make the Farsite propagation model give the same surface spread as mbedward/farsite (head/flank/back ROS and length-to-breadth ratio) for the 13 fuel models across wind, slope and moisture. Add a test comparing both, extending tests/python/farsite_flat.py, then fix one difference per PR. Includes the unused Farsite.adjustementWind (#161). Crown fire and spotting are out of scope.

first step is the test in #268, no change in src/

what it shows

head ROS is the same as the reference (6 digits, 468 cases, 13 fuel models) when the inputs are the same, so no porting bug in getSpeed
on slope the model gets sinθ instead of tanθ and the wind × cosθ, because the normal has a z (FireNode.cpp:591). at 30° the head ROS is 75-100% of the reference
flank and back are R0, there is no ellipse. flank is 4-9x slower than the reference

next PRs

slope: convert back to tanθ and horizontal wind only inside the farsite model
ellipse (richards) for flank, back and L/B

rothermel and balbi get the same sinθ, if its on purpose is up to filippi, im not touching them

done with #268 #269 #270. farsite now matches mbedward/farsite at head, flank and back on flat ground
on slopes with wind still approx, the model only sees the slope along the normal. to match it needs the whole slope vector from the core, up to filippi

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Farsite mode: match the mbedward/farsite reference #265

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Farsite mode: match the mbedward/farsite reference #265

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antonio-leblanc commented on Nov 10, 2026

antonio-leblanc commented on Nov 11, 2026

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