What is GPS (Global Positioning System), How does GPS work?

What is GPS?

GPS or Global Positioning System is a navigation system designed by the US Military (Department of Defense - DoD). GPS operates by using 24 GPS satellites that are about 11,500 miles above the sky and orbit the Earth with a speed of travel of about 2,000 mph (miles per hour) and with an orbit time of 12 hours around the Earth for at total of two orbits per day. Each satellite weighs about 2,500 pounds and are solar-powered. The length of a GPS satellite is about 17 feet and requires only a transmitter power of 50 watts. A GPS satellite has a working life of approximately 10 years.

GPS main features:
24 hours a day, 7 days a week availability
10 to 20 meter of precision and accuracy
International, worldwide, global application and coverage
Very quick and effective means of determining any location at any time and anywhere
Low cost for the end-user or consumer
Can be available to anyone

GPS main applications:
Cell phones, Smartphones
Laptops, Notebook computers
Cars, Vans, Motorcycles, Trucks, and other vehicles
Ships and other Marine or Navy vessels
Army Tanks, Armoured Vehicles, and other Ground army vehicles
Fighter planes, Jet planes, Commercial airplanes and other aircrafts
Tracking system to track vehicles, persons, pets, wildlife animals
Surveyors and surveying industry
Making of maps
Personal travel from one point to another
Travel, Tour, Tourism industry
Fun and Recreation
Camping
Fishing
Sailing
Communications
Electronic applications
and many more ...


How does GPS work?

A GPS receiver receives signals sent by the GPS satellites that are in space above the Earth. Equipped with highly precise atomic clocks, these GPS satellites transmit signals to the GPS receiver with data and information involving the time the message was transmitted, orbit information, and current location. The GPS satellites use radio waves that travel at the speed of light (186,000 miles per second) in order to send messages to the GPS receiver. The GPS receiver then uses programs and algorithms to calculate the distance the signal has traveled by determining the time it took for the signal to travel from the GPS satellite and finally arrive at the GPS receiver. GPS receiver works by means of the principle of Trilateration which is the determination of the intersection of the surfaces of three spheres. When the GPS receiver has the information on different times and locations from at least 3 different GPS satellites, it can then use Trilateration to compute its current position (or the location of the person holding the GPS receiver on Earth).



Top 10, Top 5, Top 3 GPS Navigation systems on the market

The Top 10, Top 5, Top 3 GPS Navigation systems for Cars, Boats, Planes, and any other land, sea, and air travel and navigation listed below are based on the following criteria as reviewed, experienced, and revealed by users, consumers, drivers, and product reviewing experts. The comparable features and powerful capabilities of these cool tools, driving gadgets, and helpful travel and navigation devices are mainly:

Precision and Accuracy
Ease of use
User friendliness
Display Screen Size, Screen Resolution, Color Display
Voice Recognition, Audio, Video and Media capabilities
Programmable Routes, Shortest and Most Reasonable Route
Live Online Traffic Updates and Services
Lane Assist and other Driver Help capabilities
Traffic Markers, Landmarks, and Navigation Waypoints
Bluetooth and wireless connectivity
Removable Memory size
Battery Type, Battery Life
GPS Dimensions (GPS Depth, Width, Height), GPS Weight
Warranty
Technical support
Price to features and services ratio
Durability and working life

Top 3 GPS Navigation system brands:
1. Garmin
2. TomTom
3. Magellan

Top 5 GPS Navigation system products:
1. Garmin Nuvi 755T
2. TomTom XXL 540 S
3. Garmin Nuvi 550
4. Magellan Maestro 4350
5. Garmin Nuvi 265WT