Abstract:At certain measurement rate and error, the best estimation accuracy which may be achieved by single passive observer is decided by the velocity and trajectory and trajectory of the observer, independent of the estimation algorithm. In this paper, simulation experiments show the effects of measurement rate, error and observer velocity, trajectory on the error Cramer-Rao lower bounds of position estimate under two kinds of observer trajectories. Then the best Cramer-Rao lower bounds of three kinds of observer trajectories are compared. The experimental results are very useful for design of passive target tracking system.