tellurometer
/ˌtɛləˈrɑmɪtər/
noun
- An electronic device that measures distance by sending radio waves and timing how long they take to travel to a target and back.
- The surveyor used a tellurometer to measure the distance across the valley.
- Modern tellurometers are much lighter and more accurate than the early models.
- Before GPS, engineers relied on tellurometers for large-scale mapping projects.