This paper addresses the particle filters to deal with the measurement ambiguity. In terrain referenced navigation, the ambiguous measurement update due to the similar terrain profiles causes the performance degradation and it can be the primary reason of divergence in the worst case. We proposed a method to cope with terrain ambiguity that utilizes a solution to the out-of-sequence measurement(OOSM) problem. On the other hand, the mixture particle filter is widely used to maintain the multi-modal distribution using a separate particle set for each mode. We compare the performances of these filters using numerical simulations and results are given in terms of the root mean square errors and the convergence rate.