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cs:hydrophones:pinger_bearing:start [2017/10/07 00:08]
Brian Moore General Case; Derivation and Solution
cs:hydrophones:pinger_bearing:start [2017/10/07 00:37]
Brian Moore [Generalized Solution]
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 $$ $$
-H^{-1}H\hat{P}^T = H^{-1}D \\+inv(H)H\hat{P}^T = inv(H)D \\
  
-\hat{P} = H^{-1}D \\+\hat{P}^T inv(H)D \\
  
 \begin{bmatrix} \begin{bmatrix}
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 We can see based on this structure that we need at least three hydrophones measurements ($d_1$, $d_2$, and $d_3$) to solve for the three unknown elements of unit vector $\hat{P}$. ​ Furthermore,​ the three position vectors of the hydrophones ($\vec{H_1}$,​ $\vec{H_2}$,​ and $\vec{H_3}$) must constitute an invertible, full-rank matrix. ​ In this case that simply means the three hydrophones cannot all lie on the same plane.  ​ We can see based on this structure that we need at least three hydrophones measurements ($d_1$, $d_2$, and $d_3$) to solve for the three unknown elements of unit vector $\hat{P}$. ​ Furthermore,​ the three position vectors of the hydrophones ($\vec{H_1}$,​ $\vec{H_2}$,​ and $\vec{H_3}$) must constitute an invertible, full-rank matrix. ​ In this case that simply means the three hydrophones cannot all lie on the same plane.  ​
  
-As a sanity-check,​ this formulation should re-produce the degenerate case where all hydrophones lie perfectly along the $x$, $y$, and $z$ axes.+As a sanity-check,​ this formulation should re-produce ​the solution to the degenerate case demonstrated above where all hydrophones lie perfectly along the $x$, $y$, and $z$ axes.
  
 $$ $$