I need an electrical engineer to spend a few hours looking for a commercially available RF distance meter accurate to 0.5 meters at a distance of 100 meters. The device should be small enough to be portable and be carried for 1-2 hours. RF is needed since it needs to go through walls and obstructions..
If the device is not available, then provide design consultation on a proposed design. After the proposed design is approved, then begin the full design and testing for the device.