gps
TRANSCRIPT
• Definition + History
• GPS (satellite system + signals)
• (Users segments+ competing) of GPS
• GPS receivers + limits
Plan
Definition
GPS is a space-based satellite navigation system made up of a network of 32 satellites placed into orbit by the U.S. Department of Defense.
It provides location and time information in all weather conditions, anywhere in the Earth. The system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver.
History
• 15/04/2023 • 5
The GPS satellite, GPS IIF-3, was launched
1973 1978 2010200419931989 2011 2012
The GPS satellite, GPS IIF-2, was launched
GPS satellite was launched Qualcomm announced successful tests of
assisted GPS for mobile phones. GPS was fully functional.
the first modern Block-II satellite was launched.
the first experimental GPS satellite known by Block-I GPS satellite was
launched.
GPS was created and realized by the U.S. Department of Defense (by the engineers: Ivan Getting and Bradford Parkinson) in 1973 formally known as NAVSTAR GPS, it started with 24 satellites.
The GPS satellite system
• The 32 satellites are orbiting the earth about 26,600km above us. They are travelling at speeds of 7,000 miles /h
• GPS satellites are powered by solar energy.
GPS signals• GPS satellites transmit two low power radio signals,
designated L1 and L2. • Civilian GPS uses the L1 frequency of 1575.42 MHz. • The signals travel by line of sight,
A GPS signal
The almanac
data
Ephemeris data
The pseudorando
m code
an I.D. code that identifies which satellite is transmitting information
transmitted by each satellite, contains important information about
the status of the satellite ,current date and time.
tells the GPS receiver where each GPS satellite should be at any time throughout the day.
User segments of GPS
• GPS was originally designed to provide position to the US Army, Navy and Air Force;
• GPS plays a major role in American military combat, guiding missiles and bombs to their destinations in Iraq, Afghanistan and elsewhere.
• It is used to avoid collisions in shipping, with all ocean-going vessels required to report via something known as the Automatic Identification System (AIS).
• It has revolutionized fishing, allowing fishers to return to the exact same spot they'd fished before
Competing of GPS
• The Russian Global Navigation Satellite System (GLONASS) was developed contemporaneously with GPS.
• There are also the planned European Union Galileo positioning system,.
• Chinese Compass navigation system, • Indian Regional Navigational Satellite System.
Limits of GPS
• Ideal satellite geometry exists when the satellites are located at wide angles relative to each other. Poor geometry results when the satellites are located in a line or in a tight grouping.