this is presentation for the gps

1. Global
Positioning
System (GPS)
BY : Sabin Bhat
Class : 11
Section : M15

2. GPS
• The Global Positioning System
(GPS) is a space-based radio-
navigation system consisting of a
constellation of satellites
broadcasting navigation signals
and a network of ground stations
and satellite control stations used
for monitoring and control.
Currently 31 GPS satellites orbit
the Earth at an altitude of
approximately 11,000 miles
providing users with accurate
information on position, velocity,
and time anywhere in the world
and in all weather conditions.

3. Working principle
On June 26, 1993, twenty-four GPS satellites were deployed in
space about 19,300 kilometers above the earth's surface. They orbit
the earth once every 12 hours at an extremely fast pace of roughly
11,200 kilometers per hour. These satellites are evenly spread out
so that four satellites are accessible via direct line of sight from
anywhere on the globe.
Each GPS satellite broadcasts a message that includes the satellite's
current position, orbit, and exact time. A GPS receiver combines the
broadcast signals from multiple satellites to calculate its precise
position using a process called triangulation. In this process at least
three satellites are required in order to determine a receiver's
location and a fourth satellite is also used to estimate an accuracy
of this location information.
This process can take time between few seconds to a few minutes
depending on the strength and quality of the receiver. For speeding
up the process, most GPS devices also store or cache some
information of previous location.

4. Principle of GPS: Trilateration
The working of GPS is based on the trilateration mathematical principle.
Suppose a man is standing somewhere on Earth with three satellites in the sky
above him. Consider three circles from A, B, and C which intersects exactly at
the man's position as shown in (a). Now the distance between each satellite
and the point of intersection is calculated which helps in determining the
man's position on the earth. Larger the number of satellites above the
horizon, more accurate is the location.

5. Uses of GPS
• Navigation: GPS is widely used for navigation purposes,
both in personal and commercial settings. It can provide
real-time information about the current location,
direction, and distance to a destination.
• Surveying: GPS technology is used extensively in
surveying, cartography, and mapping. It provides
accurate and precise measurements of location,
elevation, and distance, which are used for creating
maps, conducting land surveys, and tracking changes in
the earth's surface.
• Military and defense: GPS is used by military and
defense organizations for a range of applications,
including navigation, targeting, reconnaissance, and
surveillance.

6. Uses of GPS
• Agriculture: GPS is used in agriculture to optimize crop
yields, reduce waste, and increase efficiency. It can be
used to map fields, track crop growth, and monitor
irrigation systems.
• Aviation: GPS is used extensively in aviation for navigation
and flight planning. It provides pilots with real-time
information about their location, altitude, and speed,
which is essential for safe and efficient flight operations.
• Emergency services: GPS is used by emergency services
such as police, fire, and ambulance services to locate and
respond to emergencies quickly and efficiently.