Boat Gps

The Global Positioning System (GPS) of the U.S. space system is a navigation radio allows reliable positioning, navigation and timing services to civilian users on a continuous basis throughout the world - freely accessible to all.

For anyone with a GPS receiver, the system will provide a location and time. GPS provides accurate location and time for an unlimited number of people in all times, day or night, anywhere in the world.

The GPS consists of three parts: satellites orbiting the Earth, control and monitoring stations on Earth, and GPS receivers owned by users. GPS satellites broadcast signals from space that are picked up and identified by GPS receivers. Each GPS receiver then provides three-dimensional location (latitude, longitude and altitude) plus the time.

Individuals may purchase GPS devices that are easily accessible by commercial retailers. Equipped with these GPS receivers, users can accurately locate where they are and easily navigate to where they want to go, so walking, driving, flying or boating. GPS has become a mainstay of transportation systems worldwide, providing navigation for aviation, ground and maritime operations.

Relief and emergency services depend on GPS for location and timing capabilities in their rescue missions. Daily activities such as banking, mobile operations, and even control power grids, are facilitated by the precise timing provided by GPS. Farmers, surveyors, geologists and countless others perform their work more efficiently, safely, economically and accurately using the free and open GPS signals.

Three distinct sections make up the Global Positioning System. The first segment of the system consists of 24 satellites orbiting 20,000 km above the Earth in 12 hours of circular orbits. That means each satellite 12 hours to make a complete circle around the Earth. To ensure they can be detected from anywhere on the surface of the Earth, the satellites are divided into six groups of four. Each group is assigned a different path to follow. This creates six orbital planes which completely surround the earth.

These satellites send radio signals to Earth that contain information on the satellite. Using GPS receivers on the ground, these signals can be detected and used to determine the positions of receivers (latitude, longitude, altitude). The radio signals are sent to two different L-band frequencies. L-band refers to a range of frequencies between 390 and 1550 MHz. Within each signal, a coded sequence is sent. By comparing the received sequence with the original sequence, scientists can determine how long it takes for the signal to reach Earth's satellite.

The signal delay is useful in the learning of the ionosphere and the troposphere, two layers of the atmosphere surrounding the earth's surface. A third signal is also sent to the satellite receivers. This signal contains data on health and the satellite position.

The second part of the GPS ground station is composed of a receiver and antenna, as well as communication tools to transmit data to the data center. The omnidirectional antenna at each site, acting much like a car radio antenna, picks up satellite signals and transmits them to the receptor site in the form of electrical currents. The receiver then separates the signals into different channels designated for a particular satellite and the frequency at a given time. Once the signals have been isolated, the receiver can decode them and divide them into different frequencies.

With this information, the receiver produces a general position (latitude, longitude and height) for the antenna. Later, the data collected by the receiver can be further processed by scientists.