Buying a GPS unit can be easier if you know the various features that GPS receivers come with. When your needs and the features match accurately, then you need to look at the price and customer support given by GPS makers.

Your needs are generally based on what purpose you want to use a GPS. Just fascinated by features of GPS, if you decide to buy one for your car or a hand-held for boating or hiking, the entry-level models are ideal as they will also suit your budget. 

If you look for a GPS for your car, you can either go for in-built GPs or portable GPS but you need to look at the supporting features like map, display etc and choose the best car navigation system for your car. Hand-held GPS receivers come in numerous models and with different features and prices. They can be used wherever you like. GPS for boating is another widespread use of GPS and there are lots of models that you can find in the market and you can choose the best GSP.

 

GPS receivers are either designed as hand-held or portable models and in-built models. 

In-built GPS: This design is mostly used in vehicle navigation system like cars, trucks, motor cycles, boats and airplanes. Since it is installed at a fixed place in your vehicle, so you do not need to fit it in your vehicle every time. These receivers are ideal for users who want to use a dedicated navigation system for their vehicles. In-built navigation systems are more expensive than portable models. They are difficult to detach from car so you cannot use them in another car or bike or boat.

 

Hand-held GPS: Hand-held models can be taken to anywhere you like. They are ideal when you move around on feet as the whole kit just weighs about 3 or 4 ounces and are capable of doing basic as well as special functions. Hand-held models can also be used in traffic navigation system.

 

Based on the functions of GPS, we can classify GPS models into three categories

 

GPS is a navigation tool that helps you to find a location based on information received from various sources like satellites, maps from hard drives etc. Most hand-held models are quite able to cater your basic navigation requirements and provide good accompaniment while hiking or biking. Easy to carry and install, affordable prices and versatile uses are some advantages that a hand held GPS enjoys over fixed GPS units. However, reading details and maps can be a little harder due to relatively smaller screens in hand held GPS units.

The entry-level GPS units usually come with less detailed map and inadequate memory, but you will find them sufficient if you do not expect much out of them. However, when you go for advanced GPS units, they provide you voice-enabled directions to assist your navigation. 

 

Perhaps, it is one of the most wide-spread applications of GPS. Most GPS units come with pre-loaded maps which are extremely detailed and can show roads, streets and lanes. Some units can give instructions when you drive, like which turn you should take, etc. Newer GPS units have text-to-text speech feature which allows an electronic voice to tell you all instructions while you are driving. You can also select the shortest route or the most scenic route from the map database that a GPS is equipped with. Some GPS units can be linked to local traffic service to get live traffic information and helps you to take an alternative route in case your usual route is blocked.

 

These units are specially designed for use in boats and ships. These waterproof GPS units should have large memory to store numerous maps. If you use portable GPS units for your boat, you should have a well-designed mount on the boat to keep the unit at the right position.  

 

An accurate and sophisticated navigation system depends upon the features which are given below. If you add technologies like DVD, Wi-fi and Bluetooth with GPS, the cost will shoot up, but you will get a highly sophisticated GPS which can make your driving thoroughly enjoyable. Concentrate on the basic features of GPS, if you think otherwise.

 

Maps are the information sources that guide you to reach a destination. Most GPS units come already with pre-loaded maps that are often used in your country. However, if you require a map of a foreign city or a specific street, there are many ways to get the maps. Maps are available in CDs and DVD or even in some websites. GPS units come with hard drives (capacity up to 20 GB) where they store the maps. So, by simply connecting your GPS with a PC, you can download the required map through the USB port. 

 

Most GPS units have color LCD display with touch-screen feature. The dimension of the screen ranges between 3 “and 7”. In-built GPs units usually have a relatively larger display, so you can view the details easily. The smaller screens especially in hand-held GPS units can make the details hard to see.

 

A good GPS can direct you to your destination with turn-to-turn instructions when you input it. You can find the instructions on the map, but it requires your constant visual attention. Voice guidance is a new feature in car navigation system to keep your eyes more on road than on the GPS screen.  The electronic voice will tell you where you are, where you should turn and even the name of the roads and streets. You can also issue voice commands to your GPS. 

 

When you go on long business trips, the Wi-fi connectivity available in GPS units can enable you to get in touch with your family and friends. Being an additional feature and costing more, they usually come with in-built GPS.

 

If your GPS is enabled with Bluetooth technology, you can make phone calls just by linking your Bluetooth-enabled mobile with your GPS.

 

Some GPS units can play MP3 and video files or you can even get radio channels using GPS unit.  

 

 

When you buy GPS, you should check the display very carefully.

Display should be bright and sufficiently big so that maps can be read easily even in poor light conditions.

 

As a rule of thumb, colour display is better than monochrome display, as the monochrome screen may falter in poor light conditions. 

 

Also make sure that your GPS display does not reflect in ambient light conditions. Otherwise you will have visibility problems while you drive in bright sunny days.

 

Since, GPS has LCD display, it can be prone to narrow viewing angles. So check viewing angles of GPS. Since GPS will be mounted a little over your head, it should give acceptable display quality when viewed from low angles.

 

When you buy a GPS unit, usually you will get maps for your country as pre-loaded. Check whether maps are as much detailed to suit your requirements. If you require a map for your local place or a specific street but is not provided in the hard drive, you can get it from your vendor or a website.

 

When you buy a specific brand, you will find the maps provided by the maker cannot be used by other models and vice versa.  

 

New GPS units come with huge memory capacity up to 20 GB to store maps, POI, MP3, videos etc. Determine how much memory you may require before you buy a GPS unit. If you want to store a lot of maps, MP3s or other data, probably you would require a larger hard drive.  

 

 

As a rule of thumb, bigger GPS units with larger screens are generally useful at places where you receive weak signals. Smaller GPS receivers can serve as excellent portable models and they are easy to mount due to their lightweight.   

 

It is important that the antennae of your GPS should be adjusted properly to get the maximum signal strength. If you use a portable unit and wish to use it with your bike, car or boat, make sure that it can be removed and installed easily. Also check whether it has come with powerful batteries and antennaes so that you can use it outdoor for a longer time.

 

You can get special software that can convert your PC (mostly laptop) into a GPS receiver however the software is functional only in compatible operating system.

 

They come with in-built GPS and let you know the altitude so you may find it a useful feature while you are trekking or exploring.  

 

GPS can be connected to a PC or with other GPS if it has connectivity option. It enables the transfer of data and maps between the devices.  

 

When you buy advanced satellite navigation system, it is definitely going to cost you more, however, you will be offered free accessory packs and CDs that contain maps and travel information.

Does your accessory pack include different sets of antennas and booster? Because, your GPS unit may require them for maximum reception of signals.

 

A GPS unit uses touch screen display so you can operate it just by tapping the screen. Before you drive, you can feed your destination and other details into the GPS. If you want to find various routes to a particular address, feed all details - city, street etc. 

GPS have preloaded maps with all topographical features. As soon as you tap your destination into your GPS, it will display all available routes.

At anytime you have the option of choosing an alternate route which you can ask for from you GPS. The road database of GPS often provides you to select a route of your preference. It can be the most scenic or the shortest, but you are the decider. 

Glancing over the GPS screen can be distracting while you drive. So, most GPS units come with voice-enabled feature. The voice will tell you where you are, where you should turn, etc. Listening to the instructions you can drive with as much comfort. 

Before you decide to buy a car GPS unit, first assess your requirements. If you are going to install it just for navigation purpose, you can buy a simple GPS unit at affordable prices. Whether you need Wi-fi or Bluetooth or MP3 with your car GPS unit depends upon your requirements, your preference and your budget. What you should really look for is an accurate and sophisticated navigation system for your car. So, when you buy a car GPS unit, check the following features:

 

Portable or hand-held models are easy to install and remove. They are also relatively cheaper. But their small screens can make your reading of maps a little harder. If you are in habit of often removing and using it with other vehicles, you had better go for portable GPS unit. In-built GPS units come with additional features and you do not need a protective case. When you go for high-end in-car navigation system, it may be a bit expensive but you will be offered free accessory packs and CDs that contain maps and travel information.  

 

When you buy a car GPS unit, you should check the display very carefully.

Display should be bright and sufficiently wide so that maps can be read easily even in poor light conditions.

 

As a rule of thumb, colour display is better than monochrome display, as the monochrome screen may falter in poor light conditions. 

 

Also make sure that your GPS display does not reflect in ambient light conditions. Otherwise you will have visibility problems while you drive in bright sunny days.

 

Since, GPS has LCD display, it can be prone to narrow viewing angles. So check viewing angles of GPS. Since GPS will be mounted a little over your head, it should give acceptable display quality when viewed from low angles.

 

When you buy a GPS unit, usually you will get maps for your country as pre-loaded. Check whether maps are as much detailed to suit your requirements. If you require a map for your local place or a specific street but is not provided in the hard drive, you can get it from your vendor or a website mostly free of cost.  

 

New GPS units come with excellent memory capacity up to 20 GB to store maps, POI, MP3, videos etc. Determine how much memory you may require before you buy a GPS unit. If you want to store a lot of maps, MP3s or other data, probably you would require a larger hard drive.

 

This is a useful feature that you can consider whey you buy a GPS for your car. However, you need to check the audio quality.   

 

Simple GPS units are available at affordable prices. When you go for high-end in-car navigation system, it may cost you more but you will be offered free accessory packs and CDs that contain maps and travel information.

 

Does your accessory pack include different sets of antennas and booster?

It is a good idea to buy these accessories as your GPS unit may require them for maximum reception of signals.

 

Can your car GPS be linked to local traffic service to get live traffic information? 
Although you need to pay charges for using this charge, this support often helps you to get rid of many problems related to road traffic.

 

If you use a portable GPS unit and wish to use it with your motor cycle, car or boat, make sure it can be removed and installed easily. Check whether it has come with powerful batteries and antennas so that you can use it for outdoor use for a longer time.

Global Positioning System (GPS) is the most accurate and the most sophisticated navigation system in the world. The GPS receiver that enables you to determine your location is one of the three main components of the GPS system. The other two components are a constellation of 24 satellites (actually 30) and a few ground stations that constantly monitor these satellites. The GPS receiver just picks up the signals that are constantly transmitted by satellites and process them to determine its location. With the GPS system, you can know where you are even in unknown places as well as the speed and direction if you are moving.

 

It was US Department of Defense that started developing a navigation system based on satellites during early nineteen sixties. Given name as NAVSTAR, the GPS underwent a gradual evolutionary process during the next three decades. Many GPS satellites were launched during this period on experimental basis and finally NAVSTAR was successfully completed in 1993. Presently there are two dozens of GPS satellites that orbit the earth and assist the navigation system used by military as well as civilians. The maintenance of these satellites alone cost US government nearly 800 million every year not to mention the billions of dollars spent for building satellites and their launching.

 

GPS was initially used for military operations, weapon systems and tracking missiles. However, within a decade, it was made available for people in all walks of life and soon it became an essential navigation tool to be used in airplanes, ships, cars and trucks. It has also become a valuable aid to map makers, explorers, scientists, adventurers and rescuers

 

Today, GPS has revolutionized our personal navigation system. You no longer require any maps or compasses when you travel in unfamiliar places, because your small, easy-to-carry GPS receiver provides all traveling supporting information. GPS enabled transport vehicles are quite safer when compared with vehicles without GPS system. They will show your location, speed and direction and even give directions to reach your destination. As GPS provides coverage over the entire globe and your GPS receivers come with pre-loaded maps of any places, your navigation has never been safer before.

 

There are three major components that make up the GPS. They are satellites, monitor stations and GPS receivers.

 

Your GPS receivers constantly decode the signals received from the satellites to determine your location. Presently, there are 24 GPS satellites that orbit the earth and transmit signals to GPS receivers. The additional 6 satellites are presently non-operational. Each satellite moves in a circular path with a radius of 12,000 kms from earth and completes two revolutions everyday. The GPS satellites are stationed on the orbits in such a way that you can get signals from at least 4 satellites from any place at any time.

 

The data provided by GPS satellites are of three types: almanac, ephemeris and the pseudorandom code. Almanac is nothing but a logbook that records data about the position of satellites while ephemeris provides latitude and longitude details of any place on earth. Each satellite has a unique pseudo-random code so that the GPS receiver can identify the specific satellite and process its signals. There is an atomic clock onboard in the satellite to measure the time taken by the signals to reach the earth. As atomic clock is the most accurate clock, so GPS usually provides the most accurate time with a preciseness of nano-seconds. 

 

The five ground stations which are located around the globe, constantly track the path of satellites to send and receive data from satellites. Apart from the master control station at Colorado, the other monitor stations are located in Falcon AFB, Hawaii, Ascension Island in the Atlantic, Diego Garcia in the Indian Ocean and Kwajalein Island in the South Pacific. The master control station receives the information collected by monitor stations and constantly sends updated information through the antennas to the satellites back to synchronize the atomic clock in the satellites and to correct the ephemeris of each satellite.

 

 GPS receivers

GPS receivers are small computing devices that receive signals from GPS satellites and process them to determine a specific location.

 

GPS receivers are generally made up of following components:

Initially, GPS receivers had just four channels which means they could track four satellites simultaneously. However, with time and technological advancements, present GPS receivers can have 12 – 20 channels. They come with both portable and mountable designs and hundreds of models are available depending on their in-built features. The hand-held GPS receivers weigh just a few ounces and you can take them to anywhere you like to assist your navigation while the mountable GPS receivers can be installed in cars, trucks, ships, airplanes etc.

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