CST Level 1 Land Surveyor Certification Practice

What does GPS technology primarily rely on for generating measurements?

1. Direct observations of land features

2. Satellite constellations for positional inference

3. Manual calculations of coordinates

4. Visual estimations of distance

The correct answer is: Satellite constellations for positional inference

GPS technology primarily relies on satellite constellations for positional inference to generate measurements. This system operates by utilizing a network of satellites that transmit signals to GPS receivers on Earth. The receivers calculate their position based on the time it takes for these signals to reach them from multiple satellites, allowing for accurate and precise location data. The effectiveness of GPS is grounded in the principle of trilateration, which requires signals from at least four satellites to provide accurate three-dimensional positioning and precise timing. By calculating the differences in the time signals were sent and received, the GPS system can triangulate the receiver's location on the Earth’s surface. This reliance on satellite data makes GPS a powerful tool for navigation, mapping, and surveying, as it is not dependent on physical land features or manual calculations, ensuring greater accuracy and efficiency compared to other methods.