Which technology provides precise location coordinates via satellites?

• A. GIS
• B. GPS
• C. Remote sensing
• D. Cartography

Answer: (B)

GPS is the technology that provides precise location coordinates via satellites. A receiver on the ground collects signals from a constellation of satellites. Each satellite broadcasts a time-stamped signal, and by measuring how long it takes to reach the receiver, the device computes its distance to that satellite. With signals from at least four satellites, the receiver can solve for three spatial coordinates (latitude, longitude, and altitude) and correct its own clock error. This produces accurate positioning, typically within a few meters, and can be improved to sub-meter or centimeter levels with augmentation systems. Other listed technologies don’t provide live, satellite-based coordinates: GIS handles geographic data analysis, remote sensing gathers imagery and data from space, and cartography focuses on making maps.