same general concept as antenna alignment tools used by tower climbing contractors. It has both magnetic compasses and several GPS receivers in it. https://www

same general concept as antenna alignment tools used by tower climbing contractors. It has both magnetic compasses and several GPS receivers in it. https://www.viavisolutions.com/en-us/products/3z-rf-vision https://www.viavisolutions.com/en-us/products/3z-rf-vision