In order to obtain better accuracy and improved flexibility, Topcon introduced what it calls a bar code transmitter for its mm GPS. 鈥淲here a normal laser projects a thin horizontal beam, our bar code or fan beam transmitter sends a beam that effectively has a readable height of 10 m,鈥� said Ian Stilgoe, product marketing manager for survey and GPS.

鈥淚n normal circumstances a sensor needs to be at the same height as a laser transmitter to pick-up the signal, whereas with the Topcon fan beam there鈥檚 a full 10 m of flexibility. With +/- 5 m movement in the vertical plain, this fan beam transmitter lies at the heart of our mm GPS,鈥� said Mr Stilgoe.