2. A FEW QUESTIONS
Is your car or vehicle stolen and is not visible
among the several cars present?
Do you want to know the arrival for the bus you are
Are you going alone in your vehicle and your
parents want to track you movements because they
are worried about you?
Does your cargo consists of costly loads and you
want to protect them?
3. THE SOLUTION
Automatic Vehicle Locator (AVL)
What is AVL?
An automatic vehicle locator (AVL) is a device that
makes use of the global Positioning system (GPS)
and enables to remotely track the location of a
vehicle. It is an important tool which identifies a
vehicle with regard to geographic position, speed
5. COMPONENTS OF AVL
1. RADIO RECEIVER
2. GPS RECEIVER
3. GPS MODEM
5. GPS BASED STATION
6. WIRELESS COMMUNICATION
7. GPS TRACKING SOFTWARE
8. DATA STREAM PROCESSING SERVER
The global positioning system
(GPS) is a satellite-based
navigation systems made up of a
network of 24 satellites.
GPS is actually a constellation of
27 Earth-orbiting satellites (24 in
operation and three extras in case
The US military developed and
implemented this satellite netwok
as a military navigation system
but soon open it to anyone else.
8. HOW DOES THE GPS WORK ?
Trilateration :Imagine you are standing somewhere
on Earth with three satellites in the sky above you.
If you know how far away you are from satellite A,
then you know you must be located somewhere on
the red circle. If you do the same for satellites B
and C, you can work out your location by seeing
where the three circles intersect. This is just what
your GPS receiver does, although it uses
overlapping spheres rather than circles.
Radio receiver : A radio receiver is an electronic
device that receives radio waves and converts the
information carried by them to a usable form. It is
used with an antenna
GPS receiver : A GPS receiver's job is to locate four
or more of these satellites, figure out the distance to
each, and use this information to deduce its own
GPS modem : A GSM modem is used to send the
position of the vehicle from a remote place.
14. Antenna: An antenna (or aerial) is an electrical
device which converts electric power into radio
waves, and vice versa.
Base station : In a comp. network it is a transceiver
acting as a router for computers in the network,
possibly connecting them to a local area
network and/or the internet.
Wireless communication : Wireless
communication is the transfer of
information between two or more points that are not
connected by an electrical conductor.
15. GPS tracking : A GPS tracking unit is a device that
uses the Global Positioning System to determine
the precise location of a vehicle, person, or other
asset to which it is attached and to record the
position of the asset at regular intervals.
Processing : The goal of complex event processing
is to identify meaningful events (such
as threats)and respond to them as quickly as
17. WORKING OF AVL SYSTEM
The satellites are synchronized to emit encoded
navigational information (exact positioning and
Any vehicle equipped with a GPS receiver will
intercept these transmissions.
Using a simple mathematical formula derived from
triangulation, the receiver is able to calculate its
own longitude, latitude, velocity and even altitude.
Then this information is transmitted to a central
Maps allow understandable view of vehicles
location and will also allow operators to apply local
20. FLAWS IN THE SYSTEM
Ionosphere and troposphere delays - The
satellite signal slows as it passes through the
Signal multipath - The GPS signal is reflected off
objects such as tall buildings before it reaches the
receiver, thus increasing the travel time of the
Receiver clock errors - A receiver's built-in clock is
not as accurate as the atomic clocks onboard the
Fleet management: when managing a fleet of
vehicles, knowing the real-time location of all
drivers allows management to meet customer
needs more efficiently. Vehicle location information
can also be used to verify that legal requirements
are being met: for example, that drivers are taking
rest breaks and obeying speed limits
22. • Passenger Information: Real-time Passenger
information systems use predictions based on AVL
input to show the expected arrival and departure
times of Public Transport services.
• Asset tracking : companies needing to track
valuable assets for insurance or other monitoring
purposes can now plot the real-time asset location
on a map and closely monitor movement and
23. • Field worker management: companies with a
field service or sales workforce can use information
from vehicle tracking systems to plan field workers'
time, schedule subsequent customer visits and be
able to operate these departments efficiently.
• Covert surveillance: vehicle location devices
attached covertly by law enforcement or espionage
organizations can be used to track journeys made
by individuals who are under surveillance
The future prospects of GPS technology
are virtually limitless
Today’s GPS receivers are extremely
accurate. They provide a worst accuracy of