In an attempt to try and fly a drone indoors, we worked (and succeeded) on building an indoor positioning system. We used 2 sets of TREK1000 demo kits from DECAWAVE to calculate ranges from each of the anchors to our tag on the robot. We then used an iterative least squared estimation (think linear algebra and GPS) to solve for the postion which then was broadcasted via XBEE.
The eventual goal is to use migrate to the DWM1000 (much cheaper) and using kalman filters and LIDARs/ Barometers to augment the indoor postioning system

Final Iimplementation of postioning code(python) and arduino code we used on the RC Car to navigate in a room availible -> https://github.com/julianblanco/uwbLocalPosnSystem