JIMI Electronic

In the pre-PC days, taking a trip across town, a state, or the country to visit someplace you’d never been before often involved planning worthy of a major expedition. You’d have to carefully check maps, trying to figure out the shortest and fastest routes, guessing when and where you’d need to stop for gas, scribbling down notes, and highlighting roads on paper maps. That’s all changed with inexpensive and easy-to-use street navigation software. Just run a program on your PC and enter the address of your starting point and the final destination. Then, a few mouse clicks later, you’ve got both a map and exact turn-by-turn directions for how to get from Point A to Point B. And as an added bonus, if you have a laptop and Tracker For Car , you can take this software on the road with you, track your location in real-time, and get helpful hints in reaching your destination. (Most street navigation programs also have versions that run on PDAs for ultimate portability.) Several street navig...

Your  GPS Tracking Device  now has power, so it’s ready to go, right? Well, almost. After you put batteries in your GPS receiver and turn it on for the first time, don’t expect it to instantly display your location. A GPS receiver first needs to go through an initialization process before it can tell you where you are. The type of initialization and the amount of time it takes depends on what information the GPS receiver has previously received from the satellites and when. The process is mostly all automatic, and you don’t need to do much as your GPS receiver starts up and begins to acquire satellites. Your GPS user manual may contain model-specific initialization information. To initialize a new GPS receiver, take it outside to someplace that has an unobstructed view of the sky (such as a large field or a park) and turn on the power. (You did install the batteries first, right?). After the start-up screen displays, the receiver will begin trying to acquire satellites. I...

GPS might be divided up in the following way: The Earth The first major component of GPS is Earth itself: its mass and its surface, and the space immediately above. The mass of the Earth holds the satellites in orbit. From the point of view of physics, each satellite is trying to fly by the Earth at four kilometers per second. The Earth’s gravity pulls on the satellite vertically so it falls. The trajectory of its fall is a track that is parallel to the curve of the Earth’s surface. The surface of the Earth is studded with little “monuments”– carefully positioned metal or stone markers–whose coordinates are known quite accurately. These lie in the “numerical graticule” which we all agree forms the basis for geographic position. Measurements in the units of the graticule, and based on the positions of the monuments, allow us to determine the position of any object we choose on the surface of the Earth. Earth-Circling Satellites The United States GPS design calls for a t...

Several different techniques have been developed for using the  GPS tracker  to pinpoint a user’s position, and to refine that positioning information though a combination of GPS derived data and additional signals from a variety of sources. Some of the more popular techniques, such as autonomous positioning, differential positioning and server-assisted positioning, are briefly described below. Autonomous GPS positioning Autonomous positioning, also known as single-point positioning, is the most popular positioning technique used today. It is the technique that is commonly thought of when a reference to using the GPS to determine the location of a person, object or address is made. In basic terms, autonomous positioning is the practice of using a single GPS receiver to acquire and track all visible GPS satellites, and calculate a PVT solution. Depending upon the capabilities of the system being used and the number of satellites in view, a user’s latitude, longitude, a...

If a static tracking device control survey is carefully planned, it usually progresses smoothly. The technology has virtually conquered two stumbling blocks that have defeated the plans of conventional surveyors for generations. Inclement weather does not disrupt GPS observations, and a lack of intervisibility between stations is of no concern whatsoever, at least in postprocessed GPS. Still, electronic tracking devices is far from so independent of conditions in the sky and on the ground that the process of designing a survey can now be reduced to points-per-day formulas, as some would like. Even with falling costs, the initial investment in GPS remains large by most surveyors’ standards. However, there is seldom anything more expensive in a GPS project than a surprise. New Design Criteria These upgrades in accuracy standards not only accommodate control by static GPS; they also have cast survey design into a new light for many surveyors. Nevertheless, it is not correct to say th...

Direct communication between vehicles allows information exchange without requiring any fixed infrastructure or base stations. The location and velocity of vehicles is constantly changing, and the RF communication range is of fairly short distance; therefore, the set of vehicles that can directly communicate will constantly change over a short period of time. This dictates that the physical layer and the network must be capable of operating in an ad hoc, decentralized manner, although coordination and synchronization through GPS ( GPS tracker ) time signals are possible. Any two nodes must be able to communicate securely whenever they are within communication range. In a V2V network we can distinguish two modes of communication, usually designated as: • Single hop: Two vehicles are close enough to communicate directly with each other (either broadcast or point to point) with low latency. • Multihop: Vehicles that can not directly communicate may forward messages through interme...

The GPS is a constellation of twenty-four satellites (plus spares) that orbit the earth every twelve hours at an altitude of 14,000 miles from the earth's center. The system is owned and operated by the DOD, specifically the Air Force. Each satellite carries four highly accurate atomic clocks that "tick" to an accuracy of 1 nanosecond (one-billionth of a second); future satellites are expected to be accurate to between .01 and .1 nanosecond. The satellites broadcast their precisely timed radio signals through the atmosphere and onto the earth's surface at the speed oflight. The signals from each satellite arrive at any particular point on or above the earth's surface at slightly different times. GPS receivers passively calculate where they are and what time it is by comparing the signals of multiple satellites in the constellation. Receivers require an unobstructed view of the sky, so they can be used only outdoors, and they often do not perform well in forested a...

GPS Declassified examines the development of GPS from its secret, Cold War military roots to its emergence as a worldwide consumer industry. Drawing on previously unexplored documents, the military rivalries influenced the creation of GPS and shaped public perceptions about its origin. Since the United States’ first program to launch a satellite in the late 1950s, the nation has pursued dual paths into space—one military and secret, the other scientific and public. Among the many commercial spinoffs this approach has produced, GPS arguably boasts the greatest impact on our daily lives. Told by the son of a navy insider—whose work helped lay the foundations for the system—and a science and technology journalist, the research and technological advances required for the development of GPS. GPS moved from the laboratory to the battlefield to the dashboard and the smartphone, and they raise the specter of how this technology and its surrounding industry affect public policy. Insights into h...

The intricacies of GPS ( electronic tracking device ) are steeped in mathematics, physics, and engineering, but you don’t need to be a rocket scientist to understand how GPS works. GPS is composed of three parts: satellites, ground stations, and receivers. Eyeing satellites In GPS jargon, a satellite is the space segment. A constellation of 24 GPS satellites (21 operational and 3 spares) orbits about 12,000 miles above the Earth. The satellites zoom through the heavens at around 7,000 miles per hour. It takes about 12 hours for a satellite to completely orbit the Earth, passing over the exact same spot approximately every 24 hours. The satellites are positioned where a GPS receiver can receive signals from at least six of the satellites at any time, at any location on the Earth (if nothing obstructs the signals). A satellite has three key pieces of hardware: Computer: This onboard computer controls its flight and other functions. Atomic clock: This keeps accurate time wit...

A short history of GPS Military, government, and civilian users all over the world rely on GPS for navigation and location positioning, but radio signals have been used for navigation purposes since the 1920s. LORAN (Long Range Aid to Navigation), a position-finding system that measured the time difference of arriving radio signals, was developed during World War II. The first step to GPS came way back in 1957 when the Russians launched Sputnik, the first satellite to orbit the Earth. Sputnik used a radio transmitter to broadcast telemetry information. Scientists at the Johns Hopkins Applied Physics Lab discovered that the Doppler shift phenomenon applied to the spacecraft — and almost unwittingly struck gold. A down-to-earth, painless example of the Doppler shift principle is when you stand on a sidewalk and a police car speeds by in hot pursuit of a stolen motorcycle. The pitch of the police siren increases as the car approaches you and then drops sharply as it moves away. Americ...

What’s my favorite outdoor activity? Although I enjoy riding my mountain bike to work, what really turns me on is diving into a patch of thick woods and getting completely lost. If it’s an area I’m familiar with, all I need is a water bottle, an energy bar, and a hat in case I’m out after dark. So why would I buy a GPS tracker ? Because they’re small, they’re relatively inexpensive, and they provide the biggest tax-dollar bang-for-the-buck that I can imagine. When I switch on the GPS, I’m plugging into a multibillion-dollar satellite-based navigation system that is coddled in some manner by several of the largest and most powerful U.S. government agencies, including all branches of the military beneath the wings of the Department of Defense and the Department of Transportation. It’s almost irresistible once you realize the enormity of what a simple $150 cell phone–size device can do A GPS unit, coupled with inexpensive topographic-map software, allows you to preview your excursion, ...

Ancient travelers relied on celestial objects, such as stars, to find their way. GPS users also use celestial objects—satellites—to navigate. There are, of course, vast differences between a star and an earth-orbiting man-made object. You observe a star to navigate; a satellite is invisible to the naked eye, but you use its position data, or ephemera, to navigate. Modern navigators no longer have to wait for nightfall and clear skies, and, thanks to atomic clocks, they can receive precise position data continuously. According to the National Academy of Sciences, in 1957 scientists observing the newly launched Sputnik realized they could predict its position by measuring the increase and decrease in frequency of its radio signal as it orbited the earth. This observation confirmed that a satellite’s position in space could be accurately determined from the ground, which meant a satellite could determine the accurate position of an object on or above the ground, such as a hiker or a hang ...

A tracking device can simultaneously receive signals from 4 up to 11 satellites, if the receiver is on the surface of the earth. Under this condition, there are two approaches to solve the problem. The first one is to use all the satellites to calculate the user position. The other approach is to choose only four satellites from the constellation. The usual way is to utilize all the satellites to calculate the user position, because additional measurements are used. In order to focus on this subject only the four-satellite case will be considered. If there are more than four satellite signals that can be received by a GPS receiver, a simple way is to choose only four satellites and utilize them to solve for the user position. Under this condition, the question is how to select the four satellites. Let us use a two-dimensional case to illustrate the situation, because it is 24 BASIC GPS CONCEPT easier to show graphically. In order to solve a position in a two-dimensional case, three sa...

A Global Positioning System (GPS) is a group of 24 earth-orbiting satellites, providing location and time in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS Satellites. This system of satellite can work in any weather condition, operate 24/7/365 and travel at roughly 7,000 miles an hour. A GPS receiver uses a triangular calculation to pinpoint a user’s exact location buy comparing the time a signal was transmitted with the time it was received by a satellite. The control segment of GPS ( GPS tracking device ) consists of a master control station (MCS), a worldwide network of monitor stations, and ground control stations. The MCS, located near Colorado Springs, Colorado, is the central processing facility of the control segment and is manned at all times. There are five monitor stations, located in Colorado Springs (with the MCS), Hawaii, Kwajalein, Diego Garcia, and Ascension Island. The positions (or coordinates) of these...

For ages people have been looking for ways to find locations and identify directions to different places. It all began in the first century when the Chinese used lodestone ladles whose handles always pointed towards the south no matter what direction they were placed in. In the year 1978, a Block-I GPS satellite was launched. It was basically used for defense purposes. Another milestone in the GPS system is the development of Topologically Integrated Geographic Encoding and Referencing (TIGER) a digital map that allowed users to create virtual maps. This digital map was released in 1989, and sometime before that in 1983, the US president had declared that the GPS system would be made public for everyone to use. Both these factors speeded up the process of the designing and development of GPS-enabled tracking devices in the world. Over the next few decades, more research institutions and IT-based companies began to create devices based on GPS. Now, GPS has become so commonplace that...

A BRIEF HISTORY PRIOR TO atomic clocks, quartz-movement watches kept the most accurate time. Quartz time, based on the vibrations of a quartz crystal, is accurate to about one thousandth of a second perday. But with radio signals traveling at the speed of light, a clock that is off by even a thousandth of a second will produce a gross position error. Atomic clocks, accurate to within 1 second every 100,000 years, derive their precision from the highly predictable gains and losses of energy by atoms. These clocks, accurate to a billionth of a second, are key to the success of GPS. Ancient travelers relied on celestial objects, such as stars, to find their way. GPS users also use celestial objects—satellites—to navigate. There are, of course, vast differences between a star and an earth-orbiting man-made object. You observe a star to navigate; a satellite is invisible to the naked eye, but you use its position data, or ephemera, to navigate. Modern navigators no longer have to wait ...

Expensive goods and important products always need to be taken care of, but recently something improves the risk of goods. With the improvement of longer supply chains add touch points, the more and more holes appears, therefore, many criminal organizations aimed at the hole and the cargo security should concern. We can see that the cargo theft has increased 34% in 2014, and rose in Asia as well, according the professional research, the greatest risk of cargo theft currently exists in Brazil, Mexico, and South Africa, and the main method is hijacking. In fact, every market has own risk, and security managers should have a knowledge of different cultural normals and business practices. Such as some risks which caused by terrible weather, political unrest, natural disaster and others. Although people manufacture various solutions to address those risks continuously, but the criminals also continually adapt their tactics. A strategy which is a favorite tool of polices that called mot...

Nowadays everyone has noticed that more and more crime around the world but still a lot of criminals also failed to nab, in fact, it is even in a growth trend, we have to try our best to protect ourselves and our asserts while the police forces to the increasing crime wave. Recently with the inventions and developments in science and technology, a new tool has appeared, it is GPS Tracking Device . It can help us and police in our combined fighr against crime with innovations such as small vehicle tracking devices which can be easily attached to any vehicle, these small portable tracker depends on the Global Satellie Position system or GPS Tracking Device to constantly where they are or their accuate locations, speed and direction of driving. Some polices also use global positioning systems, or GPS Tracking Device in their vehicles. Because this GPS technology can deal with the emergency quickly and easily, as well as allow those policemen to pacify callers who want to know how far...