I have bought 4 RF sensors from Robokits. I want to locate one of them with the help other three sensors by the means of triangulation. My project requires this localisation under distance of 2 meters. So, how to reduce the range of these sensors to 2m ? I'm using arduino, Raspberry pi as processors for the project. Any Documentation/reference links would also be welcome. I have worked on zigbees before, this is the first time with RF.