1] Introduction to Global Positioning Systems:-
The Global Positioning System (GPS) is a satellite-based navigation system made
up of a network of 24 satellites placed into orbit by the U.S. Department of
Defense. GPS was originally intended for military applications, but in the 1980's,
the government made the system available for civilian use. GPS works in any
weather conditions, anywhere in the world, 24 hours a day, 365 days a year. The
24 satellites that make up the GPS space segment are orbiting the earth about
12,000 miles above us. These satellites are travelling at speeds of roughly 7,000
miles an hour. GPS satellites are powered by solar energy. They have backup
batteries onboard to keep them running in the event of a solar eclipse, when
there's no solar power. Small rocket boosters on each satellite keep them flying in
the correct path. Each satellite weighs about 2,000 pounds and is built to last
about ten years.
2] What is GPS?
1] GPS was invented by the United States Department of Defence.
2] The actual name of GPS is NAVSTAR (Navigation System with Time And
Ranging).
3] This system becomes fully operational in 1994.It was invented by R. L. Easton.
4] The GPS consists of 24 satellites (current 32) placed in near circular orbits
arranged in 6 orbital planes at 55 degree inclination to equator at 20,200 KM
height orbital radius.
5] The period of revolution is 12 hours so that at least 4 satellites available for
observations at any time throughout the year anywhere on the world.
4]GPS Types:-
Autonomous GPS:
Using the GPS receiver only to calculate current position
TTFF (Time to First Fix) ~ 50 seconds for a Bluetooth GPS Receiver.
Assisted GPS (AGPS):
Data Aiding - Wireless network "Assists" the GPS receiver by sending it ephemeris
data from the Base Station Almanacthat tells the receiver which satellites are
visible in sky. Saves 18-30 secs.
Temporal Aiding - Wireless Network shares its knowledge of GPS time with GPS
Receiver so it does not have to solve ambiguities. Saves 4-6 seconds.
Main benefit of AGPS is that it provides TTFF in ~10-20 seconds.
AGPS - IDEN
MLS (Mobile Location server) provides AGPS information one way from MLS to
receiver inside the handset.
Both Handset Application and Network initiated are available
AGPSCDMA
Uses Qualcomm GPSOne Technology
PDE (Position Determining Equipment) provides AGPS to the handset
MS-Assist (User Plane) - Handset Application initiated; Uses PDE on every fix
MS-Based (User Plane) - Handset Application initiated; Uses PDE on first fix and
only when needed (every 60-90 min)
Control Plane (BMF) - Network initiated via web services calls to BMF Gateway
3] Types of GPS:-
1] Global Navigation Satellite System (GNSS)
2] Global Positioning System (GPS)
3] GLONASS (Russian)
4] BeiDou (BDS) (Chinese)
5] Galileo (European)
6] Indian Regional Navigation. Satellite System (IRNSS) (India)
7] Quasi-Zenith Satellite System (QZSS) (Japan)
8] Legenda (satellite system
5] Uses of GPS:-
GPS is a powerful and dependable tool for businesses and organizations in many
different industries.
Surveyors, scientists, pilots, boat captains, first responders, and workers in mining
and agriculture, are just some of the people who use GPS on a daily basis for
work.
They use GPS information for preparing accurate surveys and maps, taking precise
time measurements, tracking position or location, and for navigation. GPS works
at all times and in almost all weather conditions.
• There are five main uses of GPS:-
1] Location :- Determining a position.
2] Navigation :- Getting from one location to another.
3] Tracking :- Monitoring object or personal movement.
4] Mapping :- Creating maps of the world.
5] Timing :- Making it possible to take precise time measurements.
• GPS use cases include:-
1] Emergency Response:- During an emergency or natural disaster, first
responders use GPS for mapping, following and predicting weather, and keeping
track of emergency personnel.
2] Entertainment:- GPS can be incorporated into games and activities like
Pokémon Go and Geocaching.
3] Health and fitness:-Smartwatches and wearable technology can track fitness
activity (such as running distance) and benchmark it against a similar
demographic.
4] Construction, mining and off-road trucking:-
From locating equipment, to measuring and improving fleet asset allocation, GPS
enables companies to increase return on their assets.
5] Transportation:- Logistics companies implement telematics systems to improve
driver productivity and safety. A lorry tracker can be used to support fleet route
optimisation, fuel efficiency, driver safety and fleet compliance.
6] Characteristics of GPS:-
1] Free
2] Accurate
3] Reliable
4] Anytime & Almost anywhere
5] Unlimited user capacity
7] HISTORY OF GPS :-
1] Developed by US Department of Defence GPS
2] 1969-Defence Navigation Satellite System (DNSS) formed
3] 1973-NAVSTAR Global Positioning System developed
4] 1978-First 4 satellites launched
5] 1993-24th satellite launched; initial operational capability
6] 1994 – Full operational capability
