A geodetic technique in which a laser signal is transmitted from a ground-based station, reflects off specially designed mirrors (retro-reflectors) placed on satellites, and is received back at the station.

A geodetic technique in which a laser signal is transmitted from a ground-based station, reflects off specially designed mirrors (retro-reflectors) placed on satellites, and is received back at the station.

• A. Radar Interferometry
• B. Satellite Laser Ranging (SLR)
• C. Lunar Geodesy
• D. Global Navigation Satellite System

Answer: (B)

The main idea being tested is how we measure precise distances to satellites using a laser. Satellite Laser Ranging sends a laser pulse from a ground station to a satellite that carries retro-reflectors, the pulse bounces back, and the round-trip time is measured to compute the distance with extreme accuracy. This setup enables precise orbit determination and monitoring of Earth’s shape, rotation, and other geodetic parameters. The retro-reflectors on satellites like LAGEOS are key to making the reflection reliable. Other methods listed use different signals: radar interferometry relies on microwaves for imaging surface movement, lunar geodesy involves ranging to the Moon rather than a satellite, and GNSS uses radio signals for positioning without laser reflection from satellite retro-reflectors. So the described technique is Satellite Laser Ranging.

The main idea being tested is how we measure precise distances to satellites using a laser. Satellite Laser Ranging sends a laser pulse from a ground station to a satellite that carries retro-reflectors, the pulse bounces back, and the round-trip time is measured to compute the distance with extreme accuracy. This setup enables precise orbit determination and monitoring of Earth’s shape, rotation, and other geodetic parameters. The retro-reflectors on satellites like LAGEOS are key to making the reflection reliable. Other methods listed use different signals: radar interferometry relies on microwaves for imaging surface movement, lunar geodesy involves ranging to the Moon rather than a satellite, and GNSS uses radio signals for positioning without laser reflection from satellite retro-reflectors. So the described technique is Satellite Laser Ranging.