  We develop an efficient algorithm for determining optimal adaptive quantum
estimation protocols with arbitrary quantum control operations between
subsequent uses of a probed channel.We introduce a tensor network
representation of an estimation strategy, which drastically reduces the time
and memory consumption of the algorithm, and allows us to analyze metrological
protocols involving up to $N=50$ qubit channel uses, whereas the
state-of-the-art approaches are limited to $N<5$. The method is applied to
study the performance of the optimal adaptive metrological protocols in
presence of various noise types, including correlated noise.
