How GPS Receivers Work

How GPS Receivers Work

by Marshall Brain and Tom Harris, howstuffworks.com

Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky.

Things are much, much easier today. For less than $100, you can get a pocket-sized gadget that will tell you exactly where you are on Earth at any moment. As long as you have a GPS receiver and a clear view of the sky, you'll never be lost again.

In this article, we'll find out how these handy guides pull off this amazing trick. As we'll see, the Global Positioning System is vast, expensive and involves a lot of technical ingenuity, but the fundamental concepts at work are quite simple and intuitive.

When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellites (24 in operation and three extras in case one fails). The U.S. military developed and implemented this satellite network as a military navigation system, but soon opened it up to everybody else.

Each of these 3,000- to 4,000-pound solar-powered satellites circles the globe at about 12,000 miles (19,300 km), making two complete rotations every day. The orbits are arranged so that at any time, anywhere on Earth, there are at least four satellites "visible" in the sky.

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 location. This operation is based on a simple mathematical principle called trilateration. Trilateration in three-dimensional space can be a little tricky, so we'll start with an explanation of simple two-dimensional trilateration.

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GPS buying guide : Getting started

GPS buying guide : Getting started

by ConsumerReport

If you often travel to new places for work or pleasure, have trouble reading maps, or simply hate to ask for directions, you might consider a global positioning system (GPS) based navigator for your car. Once you put in a destination, the system will plot a route, give spoken turn-by-turn directions, and show your progress along the route. Most personal navigation devices (PNDs) let you choose your routing preferences, including the shortest distance, the fastest time, or even routes with no toll roads. Some portable units offer special routing options for bicyclists to help them avoid highways and for pedestrians, appropriate routes are provided that ignore one-way traffic restrictions. Some devices even offer a choice for the most fuel-efficient route.

You can also use a GPS device to quickly find a variety of points of interest (POI), including gas stations, ATMs, hotels, tourist attractions, and more. Typically, you can search for a specific point of interest, browse ones that are near your current location, or look up ones in a different area. You can even choose a nearby restaurant by the type of food you wish to eat. Once you've located what you want, the system can calculate a route to get you there and often provide contact information, should you wish to call ahead.

In today's competitive market, GPS prices have come down to the point where even budget units include features previously available only on more expensive models, such as the ability to speak street names, issue speed warnings, and provide reality view, graphically representing major intersections. Higher-priced models can include such features as an FM receiver for traffic information, a wireless FM transmitter to integrate with the car's audio system, and Bluetooth connectivity, which can be handy for hands-free phone operation. Services such as traffic, weather reports, and Internet searches are widely available, although they can require a subscription or use a smart-phone data plan. Free traffic information is also increasingly common, though it is sometimes supported by small, onscreen advertising.

Extra features aside, our testing has shown that all GPS navigators will typically get you to your destination, but not always by the most efficient route. While there is no substitute for local knowledge of roads and traffic situations, some devices add intelligence through historical traffic data and the ability for users to modify maps.

How to choose

Before you buy a GPS navigator, think about your typical driving conditions, how often you're in unfamiliar areas, and the features that are most important to you.

Next, focus on how well the system works for navigation. The highest-rated models we've tested make it especially easy to enter destinations and give the most helpful directions. Look for a GPS guide device that scored well for ease of use. Some interfaces are more intuitive than others, and low-scoring units can be awkward, slow, or both. Then consider what, if any, extra features you want. We'll take you through these steps and introduce functions to consider in this GPS buying guide.

What type of driving do you do?

If most of your driving is spent commuting along the same route or running local errands on familiar roads, you might not get much use from a GPS navigator.

On the other hand, if you often encounter traffic congestion on your commute, choosing a nav system with real-time traffic information can help you avoid traffic congestion, accidents, or road construction, and plot a route around it before you even get to the trouble area. But traffic reporting on GPS units is not perfect; like other sources of traffic information, it can be inaccurate or outdated. Still, this can be a welcomed feature for many drivers.

Where and how often will you use it?

If you're buying a new car, check to see if a built-in system is available and how much it costs. These are nicely integrated into the car. But they are typically far more expensive than portable systems, both initially and for subsequent map updates. Still, if most of your driving is done in one car, or if you'd prefer not to have a unit mounted on the dash or windshield, and you're not on a tight budget, you might be happier with a built-in system.

If you often fly to new places and rent vehicles, or if you own more than one car, a portable system might be the way to go, especially with prices for entry-level systems starting at less than $100.

Another increasingly popular option is a cell phone or smart phone. With these, you don't have to pay for an expensive in-dash system or worry about carrying around a portable GPS navigator.

There are two types of phone-based navigation available. One is a subscription-based service from your cellular service provider, which typically costs about $3 dollars a day or $10 dollars a month. Downloadable navigation applications are the other option, which range in price from free to around $60. Our testing has shown that as is often the case, you get what you pay for. A server-based solution can be great in a pinch, say for a vacation or if you get lost. However, an application is a better buy for smart-phone users, as the name-brand apps have the features and performance to rival dedicated portable devices, and they have the complete map onboard, so guidance isn't dependent on a cell signal. Whichever option you choose, you'll also need to purchase a mount, car charger, and possibly a data plan for your phone, if you do not already have one.

What about extra features?

A full-featured aftermarket GPS unit can effectively upgrade an older car with features like a trip computer, Bluetooth hands-free telephone capability, MP3 player, and an FM transmitter.

Voice command is a feature that enables you to navigate on the run, allowing you to enter an address or get directions to a gas station, restaurant, hospital, or location from the POI menu simply by asking for it. However, this feature is only available on a few high-end units. Performance varies, but we've found that this feature works very well on the Garmin Nuvi 3790T.

Extras like live traffic information, weather, and local gas prices can offer an increased measure of safety and convenience, but you may have to take on a subscription fee.

Check the local laws

Check the laws in your area and the mount types available before you buy. States have been known to place restrictions on windshield mounts. Most manufacturers include a plastic disk that sticks to the dashboard to provide an alternative mounting location. Another option is a "bean bag" mount, which simply sits on the dashboard and has a rubberized surface to hold it in place.

If you travel outside the United States, look for a portable system that offers maps for navigating in other countries. Most will function in the United States and Canada, but some upper-level models from Garmin, TomTom, and others come preloaded with or can be retrofitted with maps of Europe and other regions.

Built-in battery convenience

All portables come with a rechargeable battery. If you want to use the GPS device for walking or accessing the multimedia features outside of a car, look for one that will operate for at least three hours on a charge.

While all systems include a plug for your car's 12-volt outlet, a built-in battery also gives you the option of using the power port for another device, such as a cell phone, and it eliminates cord clutter.

A battery also enables you to enter a destination and plot a route before you enter the vehicle. Some models are also packaged with a traditional AC plug for in-home use and recharging. Most also charge through a computer's USB port.

Size matters

If you choose a portable unit, size is important, especially if you frequently pack it in a suitcase. Some models are no bigger than a wallet, while others are as large as a paperback book. Look for a screen that's large enough to read easily without blocking your view. We've found a 3.5-inch diagonal screen is an acceptable compromise for travelers, but for regular use, a 4.3-inch wide screen allows more information to be displayed, thereby making it easier to enter addresses, due to larger touch-screen buttons. Several models use 4.7- to 7-inch screens, which can be easier to see in a larger vehicle with the windshield further away from the driver. For commercial trucks, vans, and RVs, it is best to purchase a special device for those applications, as they will provide guidance that factors low-bridge clearance and parkway restrictions. In addition, they typically provide detailed travel information, such as truck-stop services.

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Traffic Information Services

Traffic Information Services

by Matt Freeman

As GPS navigation systems become more and more popular, many people are discovering the fun and utility of using real-time traffic information services. These services, which work in a growing number of metropolitan areas, help keep you up-to-date on traffic conditions along routes you've programmed into your navigation system. They warn you of specific traffic incidents, including accidents and construction, which usually gives you time to adjust your route and avoid getting stuck in time-killing jams.

How does it work?

Real-time traffic data is compiled by a traffic-information provider, then broadcast over a radio frequency to equipment set up to receive it. Depending on the equipment you have, you'll subscribe to a service that's broadcast over terrestrial FM, or to one that's broadcast along with satellite radio signals. Many new portable navigators now include this real-time traffic info for free. Traffic information doesn't interfere with FM or satellite radio reception, so you can continue to listen to either source while you receive traffic signals.

The traffic information comes from a variety of sources, including commercial traffic data providers, departments of transportation, police and emergency services, road sensors, traffic cameras, and even aircraft reports. This information is compiled and delivered via radio frequency (FM or satellite) to your navigation system. These providers work with the two main companies behind map data for the U.S., Tele Atlas and NAVTEQ®, to deliver accurate representation of traffic data on GPS map displays.

In terrestrial FM applications, the traffic signals are broadcast over the FM Radio Data System (RDS), a special application of the radio band for sending small amounts of digital information. Most car stereos support FM RDS signals, which is how you can see radio station call letters or artist and song title information on your display when tuned to certain stations.

To use the service, simply program a destination into your navigation system. As you drive, your system will receive and deliver alerts whenever a traffic incident comes up. You'll get both an audible warning and a visual indicator on the navigator's map, which shows you where along your route the incident has occurred. Many systems will automatically suggest alternate routes that enable you to steer you clear of the incident ahead.

Traffic incidents include accidents, emergencies, construction, scheduled road closures, and traffic diversions for occasions such as sporting events. Some services even offer detailed information about traffic flow and the average speed along your programmed route in certain high-traffic areas of select cities.

What are the benefits?

Your primary benefit is time. More often than not, you'll get warnings of traffic incidents along your route with time enough to avoid them. And since you're using the traffic data in conjunction with a navigation system, you'll get suggestions for the most efficient alternate routes. And that means less time spent sitting in gridlock.

Traffic-information services also let you get the most out of your navigation system. Normally, you wouldn't use a GPS unit to guide you to work, or to get you back home along familiar roads. But with real-time traffic info, you'll find that your navigation system becomes an invaluable traveling tool you'll use daily.

What do I need and how much does it cost?

Basically, all you need to enjoy real-time traffic information is a traffic-ready navigation unit and, usually, an antenna (satellite radio antennas can pick up traffic-information signals as well, if you're using a compatible satellite radio receiver).

As mentioned above, some newer portable GPS units and in-dash navigation receivers include either a limited or lifetime subscription to a traffic data service. Other devices or sources require a subscription to their service. Currently, the most popular traffic-information services are provided by:

-  Clear Channel's Traffic Message Channel — also known as Total Traffic Network (FM)

-  NAVTEQ Traffic RDS (FM)

-  SiriusXM satellite radio's NavTraffic (satellite)

Pricing depends on the source. For example, satellite radio subscription prices range from $3.99 per month (in addition to the regular satellite radio subscription) to $8.99 per month. Terrestrial FM services typically cost around $60 per year.

What cities are covered?

Coverage currently includes many metropolitan areas. However, the number of cities covered grows fairly frequently, and has expanded quite a bit over the last few years. Rather than try to keep up with the list of cities, here are links to the coverage areas for the three providers listed above.

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CES 2013: Magellan SmartGPS shows that portable navigators can get smarter

CES 2013: Magellan SmartGPS shows that portable navigators can get smarter

by consumerreports

At the Consumer Electronics Show (CES) in Las Vegas, companies tireless boast of their brilliant new products. Well, Magellan goes one better with a truly smart idea, integrating social and localized content into its upcoming Smart GPS navigator.

This dashtop device has similar features to its current crop of navigators, with route guidance augmented by user ratings. Where the Smart GPS innovates is by using WiFi and Bluetooth to pull in local information to improve points of interest searches, using popular mobile services and enabling the functionality to be shared on mobile devices.

The 5-inch glass capacitive touchscreen provides quick access to information and offers via Foursquare and Yelp. Profiles are available for local businesses, along with user reviews, contact information, and one-touch routing. Plus, the connected device provides nearby gas prices, traffic information, speed camera warnings, and weather.

The data is fed to the device from the user's smart phone via Bluetooth, with the ability to pre-load information when WiFi is available, such as in your driveway or garage. Like all navigators, it can also be updated via a computer connection.

Free apps for Android and iOS enable the SmartGPS experience to continue on compatible phones and tablets.

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How to choose the best GPS navigator for the holidays

How to choose 

the best GPS navigator for the holidays

by Consumer Reports

If you're considering giving the gift of navigation this holiday season, we can point you in the right direction with our test-based advice.

The good news is, there are just three leading brands from which to choose: Garmin, Magellan, and TomTom. In years past, there were numerous companies trying to get a slice of the navigation pie, from brands you never heard of to well-established electronics companies. Competition was fierce, the barriers to entry high, and the margins low. Consequently, the field has since narrowed and the choices are simpler.

And now the bad news: There are still dozens of models and variations to choose from.

Start by identifying your budget. There are deep discounts available, with sale prices starting at less than $90, although these devices tend to bring compromises such as screen size and user friendliness. Plus, they are generally not the latest models. Realistically, you'll spend $100-$120 for a good, contemporary device. Stretch up to $160 or so, and you can get most of the common bells and whistles. Of course, there are several devices priced from $250 and beyond, adding glass screens and voice control, but those are for the rarified few.

Determine the best size. Small, 3.5-inch devices have become the exception, rather than the rule as they were a couple years ago. These are extremely portable, being conducive to removing from the car and storing in a pocket book or briefcase. However, the more common 4.3-inch size provides a larger screen, making it easier to read the maps and enter addresses. Large 5-inch devices may be a good choice for full-sized pickups, SUVs, commercial trucks, and RVs, but they are too big for a conventional car. (If you are buying for a big rig or RV driver, be sure to by a model specifically configured for their routing needs, such as those in the Garmin Dezl or Magellan RoadMate Commercial lines.)

Key features. Today, most devices include spoken street names (for natural-language route instructions) and even traffic services. Know that traffic information is imperfect, especially in the low-cost units, but it can be helpful. Consider buying lifetime traffic and map updates, as these will extend the device's usefulness and are much cheaper to purchase upfront. Model names typically include "M" or "T" to indicate these services.

Entry-level units that provide an easy-to-use interface often lack handy features, such as multi-destination routing, traffic capability, and a pedestrian mode. In the $120-plus devices, lane assist and reality view become common, two types of display that advise on how to take an exit. These can be quite helpful features, especially when traveling in unfamiliar areas.

As prices climb to $160 and beyond, Bluetooth connectivity is readily available, allowing your phone to interface with the device. This can effectively add Bluetooth functionality to an older car that may not have come from the factory with an integrated, hands-free system.

The models below target three types of buyers. They have 4.3-inch screens, unless otherwise noted. To learn the specific features and test scores, see our complete GPS ratings. An interactive tool can help you sort and filter by the factors that matter most to you.

Apps are another option. Smart phones with built-in GPS receivers and free software have proven to be true competitors to standalone devices. While our tests favor the ease of use of a dedicated device, a smart phone can effectively get you from Point A to Point B with the included Apple or Google map software. Applications from major navigation companies, such as Garmin, Navigon, and TomTom, can mimic a portable device, giving the best of both worlds. Smart phone users will want to have a dedicated mount, ideally a special-purpose one that has a built-in receiver and more-powerful speaker. A phone charger is also key, as navigation can significantly drain the battery.

Around the holidays, the nav app companies typically have special discounts. Definitely don't buy at full price. After doing the research, you might consider giving an iTunes gift card to the Apple iPhone user on your shopping list.

Wrap it up. If you do give a GPS device this holiday season, go the extra mile and preprogram it with the person's home address and some favorite locations. You can even customize it with holiday graphics, personal photos, special icons, or novelty voices, depending on the company and device.

Choose carefully, as you will hopefully be buying a welcomed traveling companion that can be a digital passenger for years to come.

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How to Buy an In-car GPS Navigator

How to Buy an In-car GPS Navigator

By Fred Zahradnik, About.com Guide

When you walk into a big electronics store, you can often try out the item you're thinking of buying, whether it's watching a big screen television, checking out a laptop's display, or listening to a stereo. Buying in-car GPS can be a bit more challenging, because you can't take it for a test drive. GPS units are often sealed in packages, and even if they're on display, it's difficult to know how they'll perform in real-world conditions.

People often become bitten by the GPS bug when they ride in a friend's car that has a GPS. By all means, try out a friend's GPS if you can, but I find that owners often don't know all of the features of their own units, or they aren't aware of important differences in performance and features up and down the price scale.

This article is designed to help you find your way through the GPS buying maze to get the best unit for your needs at the best price.

1. Understand Your Needs and Evaluate Features

Your first step is to understand what features are available; what you need based on anticipated use; what would be nice to have if you are willing to spend a little more, and what's a good value. This price and feature comparison for in-car GPS will get 

2. Read the Reviews

Here at About GPS, we acquire and test the newest and most popular in-car GPS models as they come onto the market. Every unit is rigorously road-tested, rated, and compared to others in its class in our car GPS review section.

3. Find Out More About Features Such as Traffic Detection/Avoidance and Hands-free Calling

An in-car GPS unit can do more than give you turn-by-turn directions. Most higher-end units can help you detect and avoid traffic backups and can be used, along with a Bluetooth connection to your mobile phone, as a hands-free calling device.

4. Get the Most From Your Car GPS (and Drive Safely)

Once you've purchased your car GPS, there are some simple setup steps you can take to get the most from your navigator.

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Savvy Traveling

Savvy Traveling

by Matt Freeman 

When you're out on the road, the number of tools you now have at your disposal to make your travels easier, safer, and more fun simply staggers the imagination. And it doesn't matter if "on the road" means running errands all around town or traveling from state to state: if you're behind the wheel, you can use these tools to make doing whatever you need to do that much easier — without acting as a major distraction.

Driving in a new town and need to find a restaurant that everyone will like? No problem. Want to avoid traffic jams on your way to work? Piece of cake. Accidentally leave the directions at home? You're covered. Flat tire? Out of gas? Accident? Help is easy to find. All it takes is the right tools.

Here are some great gear suggestions, and some handy tips for getting the most out of them.

Smart tools make for smart travelers.

OnStar® in any car

At this point, it's likely you've seen at least a few commercials for OnStar. It provides services like roadside assistance, crash response, and stolen vehicle assistance, and until now had only been available in GM cars and trucks. Thanks to the OnStar FMV add-on mirror, you can now get OnStar in most 1981 or newer vehicles.

Recently, we took the OnStar FMV for a spin, and came away pretty impressed. Check out our OnStar FMV video for a quick review. You can also get more details at our full OnStar FMV product presentation. We find that the system particularly excels in three areas that can help you wherever you're driving: emergencies, navigation, and daily driving aides.

The OnStar FMV replacement mirror opens up the services of OnStar to drivers of just about any vehicle.

Emergencies

Quite simply, it'll give you peace of mind to have someone on call should you find yourself with car problems like engine trouble, a flat tire, or an empty gas tank. An OnStar advisor will not only find you help, they can tell the local shop where you are, so you don't have to worry about figuring it out, which is nice if you're in unfamiliar territory.

In the case of an accident, it isn't always easy to get to or find your cell phone to call for help. This is where having OnStar is great. In many instances, the system will even automatically place the call for you.

Navigation

Your OnStar subscription lets you tap into OnStar navigation, too. With the press of a button and a quick conversation, you get spoken, turn-by-turn directions to wherever it is you want to go. Sure, you don't get maps to look at, but that's okay; there's something to be said for making your eyes your primary navigation tool. We really like that you can plot trips in advance using Google™ Maps, then send them wirelessly to your OnStar FMV. This way, you can familiarize yourself with the route a little bit before leaving the house, which makes it easier to anticipate spoken directions as you're driving.

Daily driving

Busy mornings often mean not being able to take the time to do some things before you run out the door, like checking the weather and traffic. The OnStar FMV has you covered there, too — it can give you a weather forecast and area traffic report as you're pulling out of the driveway.

The OnStar FMV system also offers Bluetooth® in two different ways. It can pair with your phone so you can make hands-free calls. You can also buy a package of minutes and use the mirror itself as your cell phone. That's great if, like me, you have a tendency to leave your phone sitting on the counter as you run out the door.

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Tips on Installing a Navigation System

Tips on Installing a Navigation System

Crutchfield Writing Team

There are three basic types of in-car navigation systems: in-dash, remote-mount, and portable. This article will give you some tips on installation considerations for each type of system, but focuses on the in-dash and remote mount systems, since they are more involved. After reading this article, see our Navigation Installation Guide for detailed installation instructions.

In-dash & Remote-mount Navigation Systems

In-dash navigation systems consist of 2 or 3 parts: a car stereo with a built-in screen, an external GPS antenna, and occasionally, a hideaway connection box that contains audio/video inputs and outputs. A remote-mount system consists of a separate navigation computer (with an external antenna) that must be connected to a compatible car stereo. Both of these navigation systems require some extra wiring connections.

Parking Brake 

For safety reasons, any video screen in the front of the car must be attached to the parking brake wire. This applies to GPS systems too. Some of the more advanced navigation functions are disabled while the vehicle is in motion. If you want to look up a phone number or change the default settings of the unit, you'll need to pull over first.

Vehicle Speed Sensor (VSS)

In addition to the standard power and ground leads, remote-mount navigation (and even some in-dash units) systems connect to a vehicle's Vehicle Speed Sensor (VSS) wire. Your vehicle's cruise control uses the VSS wire to determine the vehicle's speed—it serves the same function for the navigation system. (Don't substitute the tachometer signal wire for the VSS wire—the tach signal wire sends pulses as long as the engine is running, even when the car is sitting still.) The VSS wire sends a series of pulses (from 800 to just over 1,000 per mile) only when the vehicle is in motion. If the VSS wire is not hooked up, the navigation system will not realize that the car is moving at all, and will be unable to track position.

Reverse Signal

Many systems also connect to the vehicle's reverse (or back-up light) signal wire — this connection tells the navigation system when the vehicle is traveling in reverse. If this wire is not hooked up, then the vehicle direction will not track properly, and the navigation system won't be able to do its job.

We can help

Our highly trained Technical Support staff can provide parking brake, VSS, and reverse wire information for most vehicles. They're available seven days a week (have your invoice handy when you call). Even if the information is not available for your vehicle, they can still help you figure out which wires are the ones you need.

GPS Antenna

The navigation computer determines its position by communicating with the Global Positioning Satellites through its GPS antenna. The waterproof antenna may be mounted inside or outside of the vehicle, but best results are usually obtained by mounting it outside on the roof.

If you opt for interior mounting, keep in mind that the GPS antenna cannot "see" through metal. Reception is also prone to electromagnetic interference when mounted in the interior of the vehicle. Do not place the antenna on the dashboard or rear deck if:

-  you have a wired rear defroster

-  you have metallic window tint

-  you have a solar reflective window

-  you have a windshield mounted radio antenna

The GPS antenna must be placed at least 5" from any physical obstruction like the "A" pillar or a 2-way communication antenna. The antenna attaches to sheet metal using a magnet or adhesive, and the cable is routed to the interior through a rear window (or door) seal.

Calibration

Once installed, your navigation system must be calibrated according to the manufacturer's instructions. Most systems will also require recalibration after a tire change.

Installing a navigation unit is like putting in an in-dash CD player or an amplifier—with a few added twists. You should have no problem setting up a navigation system if you've installed this type of equipment before.

Portable Navigation Systems

Part of the appeal of portable GPS navigators is their ease of installation. Most portables use a suction cup mount to attach directly to the windshield or your dash. Power for the GPS unit is provided by a cigarette lighter power adapter.

Simply clean a small area of the windshield (not in your direct view of the road) with glass cleaner or rubbing alcohol, and attach the suction cup to clamp it securely to the glass. Your portable GPS unit may also come with another type of installation system, such as a bean bag mount that uses a weighted non-skid rubberized pad to mount on an uneven surface, or adhesive brackets to mount the unit directly to the dash.

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Connected World of Portable Navigation

Connected World of Portable Navigation

by Dominic Devito

Connected GPS for your car combines the mapping capability of GPS with the search functionality of the Internet, so you can find any type of destination you're looking for in real time. This handy feature, which is currently available on only a few GPS models, lets you use very specific search terms to find exactly what you're looking for quickly. And it offers some extra benefits for the road as well.

The old way: points of interest

Most portable GPS navigators come with a built-in point of interest (POI) database as well as detailed road maps. The points of interest typically include address and phone number information, and are grouped by the GPS navigator into broad categories, such as restaurants, shopping, fuel, transportation, and more. Then the POI are usually subcategorized one or two more times, such as dividing the "food" category into various types, such as pizza, Mexican, or coffee shops. "Transportation" can be divided into airports, train stations, subway stops, and more.

You can use the navigator's touchscreen menu to find a specific destination by going through several menu screens once you've figured out how the POI are categorized, but it can be a time-consuming process if you're not sure exactly what you're looking for or are searching for an atypical travel destination.

The new way: Internet-connected search

This is where connected GPS can make a huge difference. With an Internet-connected navigator, you can bypass the guesswork, wasted time, and sometimes missing or outdated information of the POI database and rely on real-time Internet search results to find any type of destination, from the common to the unusual. Connected GPS devices use wireless Internet connectivity to link to popular search engines such as Google™ to provide rapid results for searches. You can quickly find numerous listings for locations such as "music stores" and "pet groomers" nearby, often with helpful customer ratings when applicable. Once you locate a specific destination, it's navigation-as-usual: You get directions to go there, and maybe a phone number, with only one or two taps of the navigator's screen.

More than just search

Connected services do more than give you search capabilities — they can also provide live traffic reports in your area, weather forecasts, and local gas price information to help you save some money. You can also look up local movie times and events listings to find out what's going on in town tonight. Other features such as flight departure and arrival times, currency conversions, White Pages listings, and social networking with other GPS users help keep you informed as you travel.

Connected GPS services typically require a subscription, but most navigators that come with this capability include a free trial so you can try it out. Connected services do not work in Canada and may not be available in all areas in America — consult your GPS device's owner's manual for more details.

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Introduction to GPS Navigation

by Dominic Devito

Just a few years ago, adding a navigation system to your vehicle meant purchasing bulky components that required complex installation and the use of multiple CD-ROMs or DVD-ROMs to download the appropriate maps. Nowadays, many navigation systems come pre-loaded with maps and features designed to suit just about any budget and level of use.

Use this introduction to determine whether you want an in-dash setup that preserves your car's factory look, a portable GPS that is easy to use and install, or a handheld GPS that you can use in the mountains, on the water, and in your car. Then use our shopping guides to learn how to choose the right model for you.

Types of in-car navigation systems

In-dash Navigation

If you want to maintain the factory look of your dash and add the convenience of a large touchscreen monitor, look for an in-dash navigation system. A typical in-dash navigation system consists of a car stereo with a built-in monitor (ranging from 6-1/2" to 7"), an external GPS antenna, and sometimes a hideaway connection box that contains the A/V inputs and outputs. The stereo mounts in the factory stereo slot in your dash. The hideaway box is usually mounted behind the dash or under a front seat.

In addition to CD playback and AM/FM reception, most in-dash systems include DVD playback, so you can watch a movie on the built-in screen when the car is parked. Installation of an in-dash system can be complex, as they require connection to power, ground, the vehicle speed sensor, and the parking brake.

Remote-mount Navigation

A remote-mount navigation system consists of a self-contained GPS receiver that must be connected to a compatible in-dash stereo. Most of the time, this is the solution for someone who already has a touchscreen stereo and wants to add navigation capability. 

Portable Navigation

Compact and easy to use, portable GPS navigators are ideal for anyone who wants the convenience of in-car navigation without the hassle of a permanent installation. These portable units attach quickly to the windshield or dash and use a simple cigarette lighter adapter to draw power. This makes them easy to transfer from vehicle to vehicle. Featuring bright color screens that range from 3.5" to 7", most portable GPS receivers also include touchscreen controls, voice prompts, a built-in speaker, and an integrated GPS antenna.

Newer portable navigators are making navigation easier and driving a bit safer. GPS receivers with Bluetooth® connectivity offer hands-free phone calls and voice-command recognition. GPS devices with 2-way Internet connectivity make it possible to find a specific destination not listed in the Points of Interest. Best of all, touchscreen user interfaces have evolved to the point where many people find they can start using a portable GPS receiver without first reading the owner's manual (although you'll always get more out of your purchase by reading the manual).

Handheld GPS

Handheld GPS receivers include models designed for hiking, boating, off-road driving, geocaching, and even for use on the golf course. These are all great options for the outdoors, but are not optimized for driving. If you plan to use a GPS receiver primarily in your car, look for either an in-dash, remote-mount, or portable system, as these include special features designed specifically for use while operating a vehicle, such as voice prompts, large, bright screens, and built-in speakers.

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Portable Navigator Shopping Guide

Portable Navigator Shopping Guide

by Dominic Devito

Portable navigators are intended for use in your car, but because they're portable and have a ton of features, they are some of the most versatile forms of GPS (Global Positioning System) navigation you can get. The options, of course, can make it difficult to choose which navigation system is right for you. Read below for helpful ways to narrow down your search.

Where do you need to go?

-  Maps: Most portable navigators come with all the maps you'll ever need built right in. In most cases, you'll get maps of the contiguous 48 states, and many models also offer Alaska, Hawaii, Puerto Rico, and most or all of Canada so you can find your way, even if you're in an out-of-the-way place. Some navigators even allow you to make edits to certain aspects of their built-in maps, in case a street changes direction, your favorite restaurant moves, or there's extended construction along your route to work. Additional maps are usually available as downloads or on separate DVDs or memory cards (see below).

-  Points of interest: One of the more distinguishing features among portable navigators is the number of points of interest, or POI. POI are all the various places along a journey that might make it more fun, more educational, or be of use, such as theaters, museums, hospitals, hotels, restaurants, ATMs, and gas stations. If you want the greatest number of options for places to stop, rest, or explore, look for a device with more POI. Some advanced navigators utilize two-way Internet connectivity to provide unlimited, up-to-date consumer-rated POI for businesses, products, and services.

-  Storage capacity: Some portable navigators also offer additional maps available for download from their brand's website, so if you want a super-detailed map of New York City, or some maps for your upcoming European vacation (for units that work in foreign countries), they're right there for you. If you think you'll be uploading maps frequently, choose a unit with lots of storage space. Some websites offer additional POI as well, in case you wanted to see a more in-depth tour of your destination, or let you add your own. For handheld GPS devices used primarily for outdoor use, you can even download marine and fishery maps.

The TomTom VIA 1535 TM features a convenient EasyPort windshield mount so you can move the navigator in and out of your vehicle easily.

What about screen size and portability?

-  Screen size: Most portable navigators have touchscreen displays that range in size from 3-1/2" to 7". Smaller units, with smaller screens, are generally easier to mount and are less intrusive on your view of the road. But large displays may offer more control functions on a specific display screen than a smaller device. For instance, you might be able to see the map, as well as six other menu options on a large screen, whereas a small screen might let you view the map and one or two menu options. Larger screens can also be helpful if the ideal mounting location is far enough away to require squinting or neck-craning. A 3-1/2" display from two-and-a-half feet away can be a challenge to read for anybody.

-  Portability: Most portable navigators now are very thin, measuring from less than an inch to about an inch and a half thick. But this isn't always the case — think about how often you'll be taking your portable navigator out of the car with you, to use it for walking directions, to keep it safe, or to use in a rental after a flight. A larger navigator might be better for in-car use, but a smaller, more compact unit might be more convenient for carrying in your pocket or purse.

The Magellan RoadMate 9250T-LMB features a generous 7" color display.

Which voice?

-  Voice guidance: You'd be hard-pressed to find a navigator these days without voice guidance and a built-in speaker — but not all voice-guiding systems are created equal. Most of them will give you a list of accents and languages to choose from. If you're an Anglophile, perhaps you'd like to hear a British accent; if you're trying to learn Spanish, perhaps you'll want to switch it to the Spanish directions. Some brands now include, as part of their subscription services, celebrity voices such as John Cleese. So, if you didn't get enough of him from Monty Python, you can take him along with you on your next road trip. And if you don't like anyone else telling you where to go, some navigators even allow you to record your own voice saying key words and directions, which you can then hear as you drive.

-  Text-to-speech: One of the most exciting developments in voice-guidance technology is called text-to-speech. This means that instead of a general directive like "turn left ahead," you'll hear a reference to the specific street name: "turn left onto Greenbriar Drive." This can remove a lot of confusion at a busy intersection or when streets are close together. A navigator with this technology would be good for you if you know you'll often be driving in areas with confusing traffic patterns, or exploring unfamiliar areas.

The Garmin nüvi 3590LMT features 3D building graphics 

and lane guidance to help keep you on the right path.

Do you want more than just navigation?

Extra features: Some portable navigators include additional user functions. You might find a built-in camera, MP3/WMA playback capability or a digital photo viewer. And some units are expandable, with A/V inputs and outputs available for devices such as your DVD player, rear-view camera, or portable MP3 player.

Bluetooth® compatibility: Some navigators offer Bluetooth wireless connectivity, so you can make and receive calls with your compatible cell phone through the navigator. With many areas enacting regulations that require a hands-free device for phones while driving, this feature can come in very handy. Many navigators include a phone number with their POI information, so you can use the unit to find a destination, such as a restaurant or hotel, and then call ahead for a reservation.

Traffic updates: Some portable navigators can indicate on the screen where there are congested roads in your area or along your route. These navigators typically use auxiliary receivers — some of which are built into the 12-volt power cable — to receive traffic data reports from FM-based RDS (Radio Data System) signals or other sources, including satellite radio reports. The receiver translates the data into visual cues on the screen, showing which roads are affected and how severe the congestion is. Typically you can attempt to route around the traffic, which may take you on a longer but ultimately faster path. Traffic-info reports are usually available in and around metropolitan areas and sometimes require a paid subscription, but more and more navigators are offering free basic traffic updates. For more on traffic-info services, see our article here.

Internet connectivity: The next step for portable GPS, as with many devices, is on-demand access to the Internet. A few high-end navigators feature wireless connection to the Internet to provide real-time search results for destinations as well as access to updated travel information, such as area gas prices, weather forecasts, movie times, local events listings, and much more. These navigators generally won't allow web browsing, but they can connect to powerful search engines to help you find out-of-the-ordinary spots along the way quickly, plus consumer ratings and other useful applications.

3D building graphics: As portable navigators integrate faster processors, they're able to deliver better visual information than in the past. One example of this is 3D building graphics, which depicts important buildings or landmarks realistically on the screen, to help you visualize your surroundings better as you follow the directions either by car or on foot. These graphics are presently limited to buildings in major cities or other major attractions.

Junction view and lane guidance: To go along with the graphics mentioned above, many newer navigators feature lane guidance, which indicates on the screen the proper lane to use on a multi-lane road to ensure you won't miss an upcoming turn or maneuver. This is especially helpful in unfamiliar areas or on busy highways with many exits in quick succession. Junction view provides a detailed and realistic look at complicated intersections, including highway signs, to help ease the confusion of "mixing-bowl" scenarios with multiple ramps and levels that would be harder to follow with a simple 2-D representation.

Do you expect to use the navigator outside of your car?

Power: All portable navigators work great in your car, but most of them allow you to use them outside of your car, too. Just about every model comes with built-in rechargeable batteries, so you can sit comfortably on your couch and program in your destination before you go anywhere. You can expect to get at least an hour or two of use out of a navigator with a full battery charge, depending on how it's used. Nearly all portable navigators come with a DC power (cigarette lighter) adapter, and some include an AC power adapter as well, so you can charge and use them at home.

Traveling without your car: Many portable navigators feature different transportation modes which can route you in ways other than on paved roads. Some can find the shortest path between spots and take you off streets and sidewalks if you prefer to cross terrain, while others will guide you along sidewalks and alleys but disregard certain vehicular regulations, such as one-way streets, which is great for pedestrian travel. Some navigators can provide guidance specifically for bicycles, motorcycles, and even long-distance trucks.

For recreational activities such as off-road biking, running, hiking, fishing, geocaching, boating, and more, look into specialty handheld GPS devices. Many of these feature smaller screens but can show detailed landscapes and topographic maps. Some can help you find a fishing spot, improve your marathon time, or even help improve your golf game using GPS technology. These handheld navigators are not ideally suited for vehicular navigation, but they usually come with street and highway information and can serve that purpose if necessary.

How are you going to mount it?

Mounting: Most navigators come with a windshield mounting bracket (suction cup mount), which is one of the easiest and most easily viewable ways to install the device. These work very well with the smaller portable devices. However, some areas do not allow devices of any sort to be mounted on the windshield. Another mounting option is a disc which mounts to your dash or console with heavy-duty adhesive backing. Or you can use a portable friction mount, which is a non-slip beanbag with a mount attached to it — perfect for uneven surfaces.

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