SYSTEM OVERVIEW
In our project, GPS is used to monitor the person‟s location anywhere on earth. The who has to be located must have
GSM model with SIM GPRS enabled. The GPS consist of GPS Transmitter and GPS Receiver. In other words, the
GPS unit simply measures the travel time of the signals transmitted from the satellites, then multiplies them by the
speed of light to determine exactly how far the unit is from every satellite its sampling. By locking onto the signals
from a minimum of three different satellites, a GPS receiver can calculate a 2D (two-dimensional) positional fix,
consisting of your latitude and longitude.
So, GPS is the simple unit which triangulates the position of person. GPS Receiver receives the human longitude and
latitude from satellite through GPS Antenna. GPS receiver is interfaced with the ARM through RS232 converter. RS
232 converter is used to convert RS232 logic to TTL logic vice versa because GPS receiver is the RS232 logic and
ARM-7 is the TTL logic.
Then the receiver sends the received signal to ARM-7. Here the ARM-7 is the flash type reprogrammable ARM-7 in
which we have already programmed. Now the ARM-7 displays the persons tracking on the LCD display. Then position
information signal is transmitted through GSM network. The tracking the persons having GPS and GSM from that in
PC we can monitor the human current position on the earth.
As shown in figure1; it works on mainly two different phases. First is tracking phase and second one is the mapping
phase.
In first phase i.e. Tracking Phase the person‟s having the GPS application which can trace the location of other person
with the GSM module having SIM900 (Subscriber Identification Module) with internet access. It also includes the
current location along with the help of GPRS system.
In the second phase i.e. Mapping Phase, it shows the current location which is shown by GPS will be displayed on
Google Earth. The wide usage of GSM and GPS systems by millions of people throughout the world is for vehicle
tracking and school kids and everyone can buy as per their need.
GSM networks consist of three major systems the Switching System (SS), Base station (BS) and the Mobile Station
(MS). GSM Module is just like mobile system which consists of SIM card which can be placed in SIM card slot. This
method of communication allows a path to be established between two devices. Once the two devices are connected, a
constant stream of digital data is relayed.
A GSM modem is a specialized type of modem which accepts a SIM card, and operates over a subscription to a mobile
operator, just like a mobile phone. GSM uses a process called Switching.