Introduction:

Bangladesh is a country in South Asia. It is bordered by India on all sides except for a

small border with Burma (Myanmar) to the far southeast and by the Bay of Bengal to the

south. Together with the Indian state of West Bengal, it makes up the ethno-linguistic

region of Bengal. Bangladesh is the seventh most populous country in the world.

Bangladesh face a number of major challenges, including widespread political and

bureaucratic corruption, economic competition relative to the world, serious

overpopulation, widespread poverty, traffic congestion, load shedding and an increasing

danger of hydrologic shocks brought on by ecological vulnerability to climate change.

Modern day people do not eager to go outside their home due to traffic congestion.

Because, most of the time they are stuck in the traffic jam in Dhaka city. The government

took some necessary step to control the traffic congestion, but they are not very effective.

Now, government decides that they will take the help of Global Positioning System

(GPS) to control the traffic congestion.

What is Global Positioning System (GPS):

The Global Positioning System (GPS) is a U.S. space-based global navigation satellite

system. It provides reliable positioning, navigation, and timing services to worldwide on

a continuous basis in all weather, day and night, anywhere on or near the Earth.

How it Works:

Generally GPS is made up of three segments: Space, Control and User. The Space

Segment is composed of 24 to 32 satellites in Medium Earth Orbit and also includes the

boosters required to launch them into the orbit.

That picture is a visual example of the GPS constellation in motion with the Earth

rotating.

The Control Segment is the composed of a Master Control Station, an Alternate Master

Control Station, and a host of dedicated and shared Ground Antennas and Monitor

Stations. The control segment has four parts.

They are:

1. A Master Control Station (MCS),

2. An Alternate Master Control Station,

3. Four dedicated Ground Antennas and

4. Six dedicated Monitor Stations.

The User Segment is composed of hundreds of thousands of U.S. and allied military users

of the secure GPS Precise Positioning Service, and tens of millions of civil, commercial

and scientific users of the Standard Positioning Service.

This is the picture of a typical GPS receiver with integrated antenna

GPS satellites broadcast signals from space that GPS receivers use to provide the

dimensional location (latitude, longitude, and altitude) and precise time.

Usefulness:

Now-a-days GPS is widely used for navigating, map making, land surveying, commerce,

scientific uses, tracking and surveillance. The precise time reference is used in many

applications including the scientific study of earthquakes and as a time synchronization

source for cellular network protocols. GPS has become a mainstay of transportation

systems worldwide, providing navigation for aviation, ground, and maritime operations.

Disaster relief and emergency services depend upon GPS for location and timing

capabilities in their life-saving missions. The accurate timing that GPS provides

facilitates everyday activities such as banking, mobile phone operations, and even the

control of power grids. Farmers, surveyors, geologists and countless others perform their

work more efficiently, safely, economically, and accurately using the free and open GPS

signals.

The main aspect of this project is ‘how GPS can be used to tackle traffic congestion of

Dhaka city. Dhaka is the capital of Bangladesh. Before we discuss about the traffic

congession of Dhaka city. First we took some quick look on Bangladesh. It is officially

known as the, ‘The People's Republic of Bangladesh’ is a country in South Asia. It is

bordered by India on all sides except for a small border with Burma (Myanmar) to the far

southeast and by the Bay of Bengal to the south. Together with the Indian state of West

Bengal, it makes up the ethno-linguistic region of Bengal. The name Bangladesh means

"Country of Bengal" in the official Bengali language.

Here we saw the flag and the coat of arms of Bangladesh. Bangladesh is the seventh most

populous country and is among the most densely populated countries in the world with a

high poverty rate. Bangladesh continues to face a number of major challenges, including

widespread political and bureaucratic corruption, economic competition relative to the

world, serious overpopulation, widespread poverty, and an increasing danger of

hydrologic shocks brought on by ecological vulnerability to climate change. The other

problems which cause the people of Bangladesh lot of headache are traffic congestion

and loadsheding.

Now the Government of Bangladesh decides to use the Global Positioning System(GPS)

to control the traffic congestion of Dhaka city. For applying the GPS in Bangladesh,

Bangladesh government first undertook a project named Bangladesh GPS Network

Installation, it is takes place in February 2007 in Bangladesh.

Figure 1 - PI Michael Steckler of Lamont-Doherty Earth Observatory inspects the

antenna mount. GPS station JURI is located at the Sagarnal Health Complex in the Sylhet

Division of northeastern Bangladesh.

Participants from Lamont-Doherty Earth Observatory, Dhaka University, and the

UNAVCO Facility installed 12 continuous GPS stations across eastern Bangladesh in

February, 2007. The project, aimed at understanding the deformation associated with the

Burma Arc subduction system, includes deployment of the GPS systems for 4 years and a

rotating network of seismometers. The Burma Arc setting is particularly unique due to

the large amount of sediment from the Ganges-Brahmaputra delta being incorporated into

the subduction system, which produces a rapid broadening the accretionary prism and

foldbelt. In addition, vertical velocities from the GPS data may allow for greater insight

into possible subsidence of the delta.

Figure 2 - UNAVCO Project Engineer Nicole Feldl aligns the antenna at JURI as

Dhiman Mondal, a student of Dhaka University, watches.

Each GPS site is equipped with a Trimble NetRS receiver and Trimble Zephyr Geodetic

antenna. The receivers are programmed to record observations at 15 second and 1 second

sampling rates. Due to the scarcity of bedrock and good sky view in Bangladesh, all of

the antennas were installed on reinforced concrete column buildings; monumentation

consisted of a 5/8" diameter stainless steel all-thread rod cemented into a hole drilled into

the roof (Figures 1 and 2). The height of the antenna above the roof ranged from 13-30

cm. Eleven of the stations were powered by AC power from the host building with a 100

Amp-hour battery back-up. The site at Barkhol, accessible only by boat across Kaptai

Lake, utilized solar panels and a custom designed solar panel frame (Figure 3), with 118

Amp-hours of battery back-up.

The GPS network is focused mainly in the Sylhet Division of northeast Bangladesh and

the remote Chittagong Hill Tracts of southeast Bangladesh.

The company generally provides GPS service in Bangladesh. They are very few in

number. They are Geoplan Bangladesh and GPS Integrated. In our project we discuss

about the GPS Integrated.

General Description about the Business:

GPS Integrated provides high quality GPS Tracking Products, GPS Tracking Services to

customers and businesses across the world. They offer a variety of tracking systems that

are ideal for personal tracking, Child Tracking, Elderly Tracking or business use like

Vehicle Tracking, Fleet Management, and Truck Tracking.

Their Web & Mobile based GPS fleet management & tracking systems can help to

increase the profitability of any company. A GPS unit can allow the owner to locate the

people if they lost or in case of emergency using their GPS devices. Their vehicle GPS,

car GPS unit, auto GPS, GPS locator, GPS car tracker, GPS auto tracker, vehicle tracker

will allow the owner to monitor their vehicles.

They also offer a variety of GPS phone, cell phone GPS, GPS navigator, GPS receiver,

GPS system, mobile GPS, handheld GPS, GPS accessories, GPS tracking device, phone

tracking, pocket pc GPS, GPS device, GPS tracking cell, PDA GPS software which is

very user friendly and convenient call phone GPS tracking.

The various services they offer are vehicle tracking, GPS navigation, GPS asset tracking,

cell phone tracking , mobile tracking, GPS pet tracking, fleet GPS tracking, GPS tracking

devices, GPS mapping software, GPS tracking systems, personal tracking, truck GPS,

GPS software, GPS phone tracking.

Challenges And Opportunities of Global Positioning System (GPS):

There is no field in this world which have no challenges, in our country to build the GPS

network we will face some challenges. They are:

Lack of money to build the structure need to provide the GPS services.

Lack of experts who know about the GPS.

Lack expert organizations that can provide the GPS services effectively.

But we do not forget the opportunities we have. We have:

Can gather foreign expert who can especially know things.

Create lot of jobs the firm provide the GPS services.

Earn revenue from the firm.

Create expert HR from the help of the firm.

We should keep in head is only challenge can turn opportunity. So, we can say, the more

the challenges, the greater the opportunities. So, we should grab the opportunities turn the

challenges to opportunities.

Strategic Role of Information System:

The strategic role of information systems are divided by four types, they are:

1. Augmentation;

2. Precise Monitoring;

3. Time Keeping;

4. Carrier phase tracking (surveying);

Augmentation

Augmentation methods of improving accuracy rely on external information being

integrated into the calculation process. There are many such systems in place and they are

generally named or described based on how the GPS sensor receives the information.

Some systems transmit additional information about sources of error (such as clock drift,

ephemeris, or ionospheric delay), others provide direct measurements of how much the

signal was off in the past, while a third group provide additional navigational or vehicle

information to be integrated in the calculation process.

Examples of augmentation systems include the Wide Area Augmentation System,

Differential GPS, Inertial Navigation Systems and Assisted GPS.

Precise monitoring

The accuracy of a calculation can also be improved through precise monitoring and

measuring of the existing GPS signals in additional or alternate ways.

After SA, which has been turned off, the largest error in GPS is usually the unpredictable

delay through the ionosphere. The spacecraft broadcast ionospheric model parameters,

but errors remain. This is one reason the GPS spacecraft transmit on at least two

frequencies, L1 and L2. Ionospheric delay is a well-defined function of frequency and the

total electron content (TEC) along the path, so measuring the arrival time difference

between the frequencies determines TEC and thus the precise ionospheric delay at each

frequency.

Receivers with decryption keys can decode the P(Y)-code transmitted on both L1 and L2.

However, these keys are reserved for the military and authorized agencies and are not

available to the public. Without keys, it is still possible to use a codeless technique to

compare the P(Y) codes on L1 and L2 to gain much of the same error information.

However, this technique is slow, so it is currently limited to specialized surveying

equipment. In the future, additional civilian codes are expected to be transmitted on the

L2 and L5 frequencies (see GPS modernization). Then all users will be able to perform

dual-frequency measurements and directly compute ionospheric delay errors.

A second form of precise monitoring is called Carrier-Phase Enhancement (CPGPS).

The error, which this corrects, arises because the pulse transition of the PRN is not

instantaneous, and thus the correlation (satellite-receiver sequence matching) operation is

imperfect. The CPGPS approach utilizes the L1 carrier wave, which has a period of

which is about one-thousandth of the C/A Gold code bit period of

,

to act as an additional clock signal and resolve the uncertainty. The phase difference error

in the normal GPS amounts to between 2 and 3 meters (6 to 10 ft) of ambiguity. CPGPS

working to within 1% of perfect transition reduces this error to 3 centimeters (1 inch) of

ambiguity. By eliminating this source of error, CPGPS coupled with DGPS normally

realizes between 20 and 30 centimeters (8 to 12 inches) of absolute accuracy.

Relative Kinematic Positioning (RKP) is another approach for a precise GPS-based

positioning system. In this approach, determination of range signal can be resolved to a

precision of less than 10 centimeters (4 in). This is done by resolving the number of

cycles in which the signal is transmitted and received by the receiver. This can be

accomplished by using a combination of differential GPS (DGPS) correction data,

transmitting GPS signal phase information and ambiguity resolution techniques via

statistical tests—possibly with processing in real-time (real-time kinematic positioning,

RTK).

Timekeeping

While most clocks are synchronized to Coordinated Universal Time (UTC), the atomic

clocks on the satellites are set to GPS time. The difference is that GPS time is not

corrected to match the rotation of the Earth, so it does not contain leap seconds or other

corrections which are periodically added to UTC. GPS time was set to match Coordinated

Universal Time (UTC) in 1980, but has since diverged. The lack of corrections means

that GPS time remains at a constant offset with International Atomic Time (TAI) (TAI -

GPS = 19 seconds). Periodic corrections are performed on the on-board clocks to correct

relativistic effects and keep them synchronized with ground clocks.

The GPS navigation message includes the difference between GPS time and UTC, which

as of 2009 is 15 seconds due to the leap second added to UTC December 31, 2008.

Receivers subtract this offset from GPS time to calculate UTC and specific timezone

values. New GPS units may not show the correct UTC time until after receiving the UTC

offset message. The GPS-UTC offset field can accommodate 255 leap seconds (eight

bits) which, given the current rate of change of the Earth's rotation (with one leap second

introduced approximately every 18 months), should be sufficient to last until

approximately the year 2300.

As opposed to the year, month, and day format of the Gregorian calendar, the GPS date is

expressed as a week number and a seconds-into-week number. The week number is

transmitted as a ten-bit field in the C/A and P(Y) navigation messages, and so it becomes

zero again every 1,024 weeks (19.6 years). GPS week zero started at 00:00:00 UTC

(00:00:19 TAI) on January 6, 1980, and the week number became zero again for the first

time at 23:59:47 UTC on August 21, 1999 (00:00:19 TAI on August 22, 1999). To

determine the current Gregorian date, a GPS receiver must be provided with the

approximate date (to within 3,584 days) to correctly translate the GPS date signal. To

address this concern the modernized GPS navigation message uses a 13-bit field, which

only repeats every 8,192 weeks (157 years), thus lasting until the year 2137 (157 years

after GPS week zero).

Carrier phase tracking (surveying)

Utilizing the navigation message to measure pseudorange has been discussed. Another

method that is used in GPS surveying applications is carrier phase tracking. The period of

the carrier frequency times the speed of light gives the wave length, which is about 0.19

meters for the L1 carrier. With a 1% of wave length accuracy in detecting the leading

edge, this component of pseudorange error might be as low as 2 millimeters. This

compares to 3 meters for the C/A code and 0.3 meters for the P code.

However, this 2 millimeter accuracy requires measuring the total phase that is the total

number of wave lengths plus the fractional wavelength. This requires specially equipped

receivers. This method has many applications in the field of surveying.

We now describe a method which could potentially be used to estimate the position of

receiver 2 given the position of receiver 1 using triple differencing followed by numerical

root finding, and a mathematical technique called least squares. A detailed discussion of

the errors is omitted in order to avoid detracting from the description of the methodology.

In this description differences are taken in the order of differencing between satellites,

differencing between receivers, and differencing between epochs. This should not be

construed to mean that this is the only order which can be used. Indeed other orders of

taking differences are equally valid.

The satellite carrier total phase can be measured with ambiguity as to the number of

cycles as described in CARRIER PHASE MEASUREMENT and CARRIER BEAT

PHASE. Let denote the phase of the carrier of satellite j measured by

receiver i at time . This notation has been chosen so as to make it clear what the

subscripts i, j, and k mean. In view of the fact that the receiver, satellite, and time come in

alphabetical order as arguments of and to strike a balance between readability and

conciseness, let so as to have a concise abbreviation. Also we

define three functions, : which perform differences between receivers,

satellites, and time points respectively. Each of these functions has a linear combination

of variables with three subscripts as its argument. These three functions are defined

below. If is a function of the three integer arguments, i, j, and k then it is a valid

argument for the functions, : , with the values defined as

,

, and

.

Also if are valid arguments for the three functions and a and b are

constants then is a valid argument with values defined as

,

, and

.

Receiver clock errors can be approximately eliminated by differencing the phases

measured from satellite 1 with that from satellite 2 at the same epoch as shown in

BETWEEN-SATELLITE DIFFERENCING. This difference is designated as

Double differencing can be performed by taking the differences of the between satellite

difference observed by receiver 1 with that observed by receiver 2. The satellite clock

errors will be approximately eliminated by this between receivers differencing. This

double difference is:

Triple differencing can be performed by taking the difference of double differencing

performed at time with that performed at time . This will eliminate the ambiguity

associated with the integral number of wave lengths in carrier phase provided this

ambiguity does not change with time. Thus the triple difference result has eliminated all

or practically all clock bias errors and the integer ambiguity. Also errors associated with

atmospheric delay and satellite ephemeris have been significantly reduced. This triple

difference is:

Triple difference results can be used to estimate unknown variables. For example if the

position of receiver 1 is known but the position of receiver 2 unknown, it may be possible

to estimate the position of receiver 2 using numerical root finding and least squares.

Triple difference results for three independent time pairs quite possibly will be sufficient

to solve for the three components of position of receiver 2. This may require the use of a

numerical procedure such as one of those found in the chapter on root finding and

nonlinear sets of equations in Numerical Recipes. Also see Preview of Root Finding. To

use such a numerical method, an initial approximation of the position of receiver 2 is

required. This initial value could probably be provided by a position approximation based

on the navigation message and the intersection of sphere surfaces. Although

multidimensional numerical root finding can have problems, this disadvantage may be

overcome with this good initial estimate. This procedure using three time pairs and a

fairly good initial value followed by iteration will result in one observed triple difference

result for receiver 2 position. Greater accuracy may be obtained by processing triple

difference results for additional sets of three independent time pairs. This will result in an

over determined system with multiple solutions. To get estimates for an over determined

system, least squares can be used. The least squares procedure determines the position of

receiver 2 which best fits the observed triple difference results for receiver 2 positions

under the criterion of minimizing the sum of the squares.

The Global Positioning System (GPS) is generally a military project. Though now it is

use for also for civilian purpose. We think, GPS used by military give strategic

advantage. They are:

Navigation: GPS allows soldiers to find objectives in the dark or in unfamiliar

territory, and to coordinate the movement of troops and supplies. The GPS-

receivers that commanders and soldiers use are respectively called the

Commanders Digital Assistant and the Soldier Digital Assistant.

Target tracking: Various military weapons systems use GPS to track potential

ground and air targets before they are flagged as hostile. These weapon systems

pass GPS co-ordinates of targets to precision-guided munitions to allow them to

engage the targets accurately. Military aircraft, particularly those used in air-to-

ground roles use GPS to find targets (for example, gun camera video from AH-1

Cobras in Iraq show GPS co-ordinates that can be looked up in Google Earth).

Missile and projectile guidance: GPS allows accurate targeting of various military

weapons including ICBMs, cruise missiles and precision-guided munitions.

Artillery projectiles with embedded GPS receivers able to withstand accelerations

of 12,000g's or about 117,600 meters/second2 have been developed for use in

155 mm howitzers.

Search and Rescue: Downed pilots can be located faster if they have a GPS

receiver.

Reconnaissance and Map Creation: The military use GPS extensively to aid

mapping and reconnaissance.

The GPS satellites also carry a set of nuclear detonation detectors consisting of an

optical sensor (Y-sensor), an X-ray sensor, a dosimeter, and an electromagnetic

pulse (EMP) sensor (W-sensor) which form a major portion of the United States

Nuclear Detonation Detection System.

The Ethical And Social Implications For The Mass People:

Global Positioning Systems is a new concept in our country. Only a few company have

get permission to provide GPS service in Bangladesh. This step will take the country one

step further because this kind of service is really a important service for country like us.

This service will help the general people those who spent most of their time in traffic

jam. It is a very innovative way to use GPS to solve traffic jam. As the country, like

Bangladesh jam controller is traffic police but they cannot be able to control it

effectively.

Through the Global Positioning System (GPS) traffic can know which road is getting

more congested so they can take the necessary measure which will lessen the traffic

congestion. Such as, they can open the new bypass road and they can send some more

traffic to control the congestion.

Most of the jam is created by some of the unruly driver; by the help of the GPS we can

able to know which drivers are doing that, and take necessary actions against those

drivers. This will help less the traffic congestion of Dhaka city and this will also help to

increase the ethical value of mass people.

Conclusion And Recommendation:

Global Positioning System (GPS) is a new concept in our country. It will help our

country to take one step further than our neighboring country, but our country does not

have the technological experts in this field, does not have the sufficient technology, does

not have sufficient money to build infrastructure.

So, the government should take some necessary step to collect fund to build the

infrastructure, because build these kind of structure is taking a huge time and money, so it

would be wise if government does not wait longer. Government can give jobs to foreign

experts, so they can fill up the place of technological experts. They can also teach the

students of how the GPS work or made them expert about it. By the help of them we

generally fill up the gap of technological experts and the trainer of the technological staff.

Though Global Positioning System (GPS) is a new thing, but it will help us our country

to one step further which will very important in our competitive world. This will not only

help us to control the traffic congestion of Dhaka city but it will also help to prevent the

theft of the vehicle, misplaced the fleet, theft of mobile, theft of kid, finding the lost pet,

get the correct time etc. So, government should give the necessary support to establish the

Global Positioning System in Bangladesh.