Target-based fiber assignment for large survey spectrographs

Next generation massive spectroscopic survey projects have to process a massive amount of targets. The preparation of subsequent observations should be feasible in a reasonable amount of time. We present a fast algorithm for target assignment that scales as O(log(n)). Our proposed algorithm follow a target based approach, which enables to assign large number of targets to their positioners quickly and with a very high assignment efficiency. We also discuss additional optimization of the fiber positioning problem to take into account the positioner collision problems and how to use the algorithm for an optimal survey strategy. We apply our target-based algorithm in the context of the MOONS project.