added some comments. more to-do

tex/chapters/estimation.tex

@@ -26,6 +26,7 @@ In the case of particle filters the MMSE estimate equals to the weighted-average
     \hat{\mStateVec}_t := \frac{1}{W_t} \sum_{i=1}^{N} w^i_t \mStateVec^i_t \, \text{,}
 \end{equation}
 \commentByMarkus{Passt die Notation so?}
+\commentByFrank{sieht fuer mich auf den ersten blick nach korrektem weighted average aller partikel aus}
 where $W_t=\sum_{i=1}^{N}w^i_t$ is the sum of all weights.
 While producing an overall good result in many situations, it fails when the posterior is multimodal.
 In these situations the weighted-average estimate will find the estimate somewhere between the modes.