You can use a sensor array to find the position. My suggestion would be to read up on "beamforming." Once you have the system identifying the position, direction, etc -- I would guess getting it onto the display would actually be the easy part. If you did it with an array of ultrasonic sensors, this might be easy to do. Sound travels about 343 m/s in air so you can measure the difference in arrival time at your sensors with a micro. One issue with using sound is 1) might not go far enough and 2) you get multiple returns for each pulse from your transmitter (hits walls, cars, etc).