A high precision distance sensor based on ultra wideband（ UWB）-P410（ PulsON 410） is introduced

and two ranging modes based on ranging and communications module（ RCM） and radar module（ MRM） and their principle are elaborated

discusses principle of typical indoor positioning system and related algorithms. The positioning system with reference nodes are arranged as an equilateral triangle is established on the basis of trilateral localization algorithm

then positioning and tracking of single moving target in two modes is implemented respectively. The positioning precision of the sensor in the ranging mode is analyzed. Simulation experiment results show that the position error distribution rule of this system is reduced gradually from trilateral to the center of mass inside equilateral triangle

it provides basis for further optimization of positioning precision of this system.