describe gps and its application. how gps and gis are different?

GPS, or Global Positioning System, is a satellite-based navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.

Here's how it works, step by step:

1. The GPS system consists of a network of about 30 satellites orbiting the Earth at an altitude of 20,000 km.
2. Each of these satellites transmits signals towards the Earth.
3. A GPS receiver on the Earth picks up these signals from multiple satellites.
4. By calculating the time it took for each signal to reach the receiver, the receiver can determine the distance to each satellite.
5. With the distance to at least four satellites known, the receiver can calculate its own position.

Applications of GPS:

1. Navigation: GPS is widely used in navigation systems in cars, airplanes, and ships.
2. Mapping: GPS is used in creating and updating maps.
3. Surveying: GPS provides accurate location information, useful in surveying and geology.
4. Timing: GPS provides precise timing information, used in many applications including scientific study of earthquakes, synchronization of telecommunications networks, and even in the trading of stocks.

GIS, or Geographic Information System, on the other hand, is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data. It's a computer-based tool that analyzes, stores, manipulates and visualizes geographic information, usually in a map.

The difference between GPS and GIS is that GPS is a system that provides location and time information anywhere on or near the Earth, while GIS is a computer system that captures, stores, checks, and displays data related to positions on the Earth's surface. In other words, GPS provides the necessary location data that GIS uses for its operations.