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PD1= ?¯ (XL1 - XH )² + (YL1 - YH)² + ?t0 . ? .................... (A)
Similarly for other 2 landmarks:
PD2 = ?¯ (XL2 - XH )² + (YL2 - YH)² + ?t0 . ? .................... (B)
PD3 = ?¯ (XL3 - XH )² + (YL3 - YH)² + ?t0 . ? .....................(C)
We need to linearize (A), (B) & (C) to solve them
Using Taylor Series:
f(x0) . ( x- x0) f ' (x0) . (x - x0)
f
= f (x0) + ----------------- + ---------------------
1! 2!
Considering the simplified part first
f = f (x0) + f(x0)(x - x0)
put (x-x0) = ?x