Monday, February 17, 2003
GPS Navigation Shootout Intro - Will You Get There or Get Lost?
Posted by Gary Garland, Esq. in "THOUGHT" @ 12:05 AM
This is the introduction to our GPS Navigation Series. This collection of articles will delve into the hardware available for the Pocket PC, the software, some alternatives, and what the future holds in this field. Let’s go!
There are roughly six major GPS offerings for the Pocket PC. The best are quite good. The worst are frightening and couldn’t help you find your way out of a paper bag (and will crash your Pocket PC, to boot)! Which has the best hardware? The best software? Come, dear reader, settle down with your latte and join us.
We will begin our series with an explanation of what GPS is, some of the nomenclature, and certain expectations. Next, we’ll discuss the hardware, trends, and expectations. Then, we’ll come to the software which can make or break the best of hardware. We’ll also look at the Garmin StreetPilot III stand alone car navigation unit, and compare to our Pocket PC brethren in performance. Lastly, we’ll round up everything and talk about each which application is better at certain tasks. In a rush to go out and buy a system now? I’ll kill the suspense and tell you www.mapopolis.com has my favorite software, and it is so inexpensive I would call it a best buy. Destinator is also a very capable program, but not my first choice. Think of Ginger vs. Mary Ann, or think of Mapopolis as gin and tonic, while Destinator is a martini. I know, I know, you don’t agree with me. Well, that’s why everyone has his own opinion - I’ve done my best to give a clear, unbiased view based on my experiences with these packages. There can be compelling reasons to buy a different package, as will become evident in the next few articles.
Figure 1: What a mess! Offerings from Mapopolis, Destinator, Pharos, Teletype, CoPilot, Navman, Holux and Garmin
Who are you, anyway, Mr. GPS?
Err, not exactly. I’m just a poor shmo. My wife’s car has a great in-dash system, and I was looking for as close to that performance as possible out of my iPAQ. I don’t have access to Consumer Reports’ test labs, and don’t claim to be an expert. I think it’s safe to say my experiences would mimic someone who has purchased any (or all) of these packages, and used each for roughly five to 10 hours. Of course, the longer you use any of these packages, the more gems you find - maybe a better way to do something, maybe a feature you didn’t realize was present. I read documentation as necessary - if any one of these were my only GPS package, I would have thoroughly read the documentation. Also, I’ve tried to do my homework, and have a fairly good understanding of what goes on with GPS positioning, what the software does, and what the software should do. Finally, I’ve had a chance to talk/write/meet some of the folks behind the scenes, so I have an idea of what’s yet to come.
Why this wimpy disclaimer? Well, to minimize whatever flaming I’ll receive in the discussion forums, of course! Also, because I want to make some points clear. Although I’ve done as much research as I could, and put more than 40 hours into the research and review of these systems, I will undoubtedly make mistakes - these are complex packages, and there is room for errors. Plus, I have tried to obtain some information from vendors which they simply could not provide.
As a general guideline, if I’m reasonably sure something is a fact, there will be no hedging. If I’m pretty sure about something, I’ll make that known to you also. Hopefully any corrections in the forum will be just that - corrections - and if necessary, perhaps any major errors will be changed in the appropriate section to reflect the comments.
Lastly - why is this whacky author being so familiar, with terms like “my experience,” “I saw,” etc. - well, dear reader, while not the most professional way to write an article, I do believe it is appropriate. For all intents and purposes, you’re driving along with me to my home and office. And you didn’t even chip in for gas, so I think we can skip a few formalities, don’t you? Okay, now to the heart of this intro:
What exactly is GPS and NMEA?
GPS stands for Global Positioning Satellites. A GPS receiver essentially picks up a radio signal beamed from three or more of the 24 orbiting GPS satellites the U.S. Department of Defense was kind enough to launch into space for a mere (Dr. Evil voice) $12 billion dollars. By measuring the time it takes for the signal from each satellite to reach the receiver, the GPS unit is able to calculate the distance to each satellite, and ultimately provide latitude and longitude coordinates of the receiver, typically within 15 to 100 feet for civilian use. NMEA is the National Marine Electonics Association, and the NMEA 0183 is the standard protocol interface. Don’t worry, you won’t be tested on this, but at least in theory, any receiver that is compliant should be able to export to compliant software. The receivers output information in text, and the software reads that text and easily translate the position with all the hard location number crunching done by the receiver. In English, you should be able to use compatible software (from other manufacturers) with your hardware.
If three Satellites are Good, and four are better, what about 12?
Most receivers can track up to 12 satellites at once. The Digitraveller can track 16. When your receiver picks up three satellites, it knows your latitude and longitude, i.e. where you are on Earth, and your software can operate in 2D (two dimensional) mode, which is fine for driving. Locking onto a fourth satellite gives you altitude, which is just a curiosity in a car, but pretty useful when flying (bearing in mind the error rate, discussed below).
Your receiver will attempt to lock onto as many satellites as it can. When it has a lock on three, it begins transmitting your coordinates to your software and you’re in business, unless your software requires a 3D fix. It is my understanding that more than four satellites is simply overkill - it does not result in greater accuracy, but it simply allows your receiver some backup data in case a weak signal is lost. The exception may be Garmin - the specs on the StreetPilot III imply it uses data from all 12 satellites at once. The unit has demonstrated (through its own diagnostics) accuracy that varies according to conditions, but at one point it told me it was accurate within 15 feet - sweet! If anyone has information which differs, kindly mention it in feedback - the vendors I have had contact with know their software far better than their hardware.
Just who is NavTech?
Navigation Technologies (NavTech) is an impressive company. All the North American factory installed car navigation systems use NavTech. They also supply mapping data to on-line sites including www.mapquest.com, etc. These are the big boys.
Some packages use data other than from NavTech. I have yet to find any major discrepancies (but have found a bit which will be mentioned in the reviews). Obviously, if NavTech missed a road or incorrectly classified it, you’d expect all packages with that map to have those flaws. I think it's reasonable to expect the data to be accurate to within two years. Huh? I expect a two-year-old road to be on the map, I don’t expect a one year old road to be present.
The mapping information is incredibly complex. Per NavTech, each road segment has an incredible 150 attributes, including turn restrictions, speed limits, number of lanes, one or two way, height restrictions, lane dividers, and about 145 or so things I can’t think about. The software is only as good as the maps. You would expect all packages using NavTech to get the same results, but they don’t, and that’s where the real problems lie, as we’ll discuss in the individual reviews.
What’s the POInt?
Just about each mapping package includes Points Of Interest. Each seems to come from a different source, some include phone numbers, etc. Just like roads, it’s reasonable to expect a lag time from when a business is established (or closed) until that data is reflected in the software. Figure a two year lag time, a number I pretty much made up, but I think it’s about right.
The packages differ in what’s included with their software. To my knowledge, www.mapopolis.com is the only vendor to charge separately for Points Of Interest. At $25 for the entire U.S., it's well worth it.
I would like to note, for virtually any of the systems, do not expect many of your favorite strip malls to be listed - that also includes their addresses. Most programs will treat their address as if they were actually on the road instead of in a giant parking lot. That means the ability to pick a location from the on screen map may be more important than you would have initially thought.
How does a car’s built-in GPS system differ from a Pocket PC’s?
Well, aside from about $1,800, my reference system is my wife’s Honda Odyssey, with the top rated GPS system made by Alpine. Her GPS is augmented with a dedicated DVD player, gyroscope and wheel sensors. The wheel sensors help ensure accuracy and can compensate for situations when the signal is lost, such as in a tunnel. The gyroscopes (solid state, not the spinning tops you put on a pencil as a kid) allow the system to know when the van just made, say, a right turn, allowing the system to calibrate to the road.
A handheld GPS receiver potentially has a smaller antenna than a vehicle’s. Also, there are no wheel sensors, so a lost signal is fatal to positioning, unless an algorithm attempts to guess the vehicle's location based on prior speed and direction. Finally, I am not aware of any handheld GPS receiver with a gyroscope, which I believe is a good thing, as the Pocket PC’s position is calculated based on the difference between the current location and the prior location, regardless of whether the Pocket PC is flat or rotated, making for potentially more accurate Pocket PC readings.
As a quick example of how a Pocket PC’s receiver calculates speed and position, think about standing in a spot, shouting, and then moving to another location and shouting. While the GPS receiver “receives” instead of transmitting/shouting, it does calculate the distance between the current location and the last location (say, one second ago), and also the direction between the two. Using simple math (not so simple for me) software can calculate your position and speed.
The three elements of a Pocket PC GPS Navigation system
Obviously, we need a receiver, which can come in several forms - a detached unit, such as Radio Shack’s $99 Digitraveller which has separate electronics and plugs into the serial port, a sleeve such as the Navman which functions in lieu of a CF jacket, and a CF card receiver which plugs into the CF slot. New entries include the family of Bluetooth GPS receivers, which are not attached to the Pocket PC. A Bluetooth receiver actually transmits the GPS information to the Pocket PC via Bluetooth, opening up some different possibilities as explored below. (Talk about misnomers - a Bluetooth “receiver” receives satellite signals, but then transmits data via Bluetooth - still, it sounds better than saying, “Bluetooth Transceiver”).
In addition to the receiver, there need to be two aspects of the software to make things work. First, there has to be the database that has the information of where things are - here’s a road, there’s a lake, and there’s a landmark or restaurant. Second, you need the software to make it work - the software must make the map usable, and more importantly, for navigation it must calculate the route which is the primary function of navigation software.
The general installation involves loading software into your PC, loading software/drivers onto the Pocket PC, and finally selecting the map area(s) you wish to export to the Pocket PC. Each vendor has a different method of exporting the data. While one vendor may let you download each county individually, another may require you to download 40 megs at a time, which could include several states.
More Errors than Ted Kennedy
Most of the receivers state an accuracy of roughly 10 to 15 meters 95% of the time. That means, most of the time, you will be off by 45 feet, and the rest of the time, you’ll likely be off by quite a bit more (and once in a while, even more accurate)! Shabby electronics? Not at all - these things must calculate radio signals coming at the speed of light. Each receiver has proprietary algorithms to account for atmospheric distortion, reflections from trees, buildings, your neighbor’s dog, wind turbulence, your windshield, etc. What that means is you have to have the right expectation of the software, which must operate under the assumption that the data it's receiving is faulty. Even the best software may think you’ve turned when you haven’t (but should correct in a second or so), and can tell you to turn in 100 feet when it is really 50 feet or 150 feet. For the most part, roads are not so close together that the error is significant, but it is something to be aware of.
Lastly, you need to hold your beloved new navigator. I will post a review of mounts when completed, but I will say this: it is far more useful and gratifying to have your Pocket PC securely held in a suitable location than to drive with it on your lap. Trust me.
Glance-O-Rama
While driving, you obviously can’t stare at the display (something about keeping your eyes on the road). There is definitely a difference between how you use these programs while at home, or while driving.
While your vehicle is in operation, chances are you will become adept at speed reading/glancing at your display, probably in ˝ second bursts. Glance at the display, drive, repeat. There is just so much information you can get in ˝ second (maybe closer to 1/4 second?) During those quick glances, very often the map information will be relatively useless and you’ll want to rely on verbal prompts, and possibly arrows and/or words which visually cue how you’ll proceed. When you use one of these solutions, you’ll likely want to thoroughly familiarize yourself with what you’ll see while driving. Pharos and StreePilot III are the only packages with a simulation mode which let you see your route, turn directions, signals etc. from the comfort of your home (or parked car).
Finally, a quick warning- use common sense when you look at your Pocket PC or set up the routes in the car - simply pull over. The display, whether on a Pocket PC or in dash navigation system, can be distracting, so be smart and spend time playing with the features until you are proficient. Some of the packages have driver/passenger mode, so the driver sees less distractions and has an easier time of things. I am an accident lawyer by trade, and not looking to pick up new business from Thoughts readers! During these tests, I had no less than three near accidents - twice while my wife and baby were on board. The scary part? I was not looking at the GPS displays at the time - I had looked at the displays a few seconds before, and was thinking more about what I had seen than about what I was doing. Okay, no more lectures.
Which hardware is best?
We’ll cover hardware choices in the next segment, “GPS Hardware Review” and also discuss some general mounting guidelines and suggestions. Following that, I’ll explain the test routes and methods used, and show some screen comparisons. Then we can finally get into the heart of these reviews!
Conclusions
I hope you found this introduction informative and not too boring. These few introductions are necessary so you can make an informed decision of which GPS package, if any, deserves your hard earned cash. Although I've spent hours with the hardware, I need to try it in the harshest environment I know, other than by my cats' litter box: the steel canyons of Manhattan. So long for now!
There are roughly six major GPS offerings for the Pocket PC. The best are quite good. The worst are frightening and couldn’t help you find your way out of a paper bag (and will crash your Pocket PC, to boot)! Which has the best hardware? The best software? Come, dear reader, settle down with your latte and join us.
We will begin our series with an explanation of what GPS is, some of the nomenclature, and certain expectations. Next, we’ll discuss the hardware, trends, and expectations. Then, we’ll come to the software which can make or break the best of hardware. We’ll also look at the Garmin StreetPilot III stand alone car navigation unit, and compare to our Pocket PC brethren in performance. Lastly, we’ll round up everything and talk about each which application is better at certain tasks. In a rush to go out and buy a system now? I’ll kill the suspense and tell you www.mapopolis.com has my favorite software, and it is so inexpensive I would call it a best buy. Destinator is also a very capable program, but not my first choice. Think of Ginger vs. Mary Ann, or think of Mapopolis as gin and tonic, while Destinator is a martini. I know, I know, you don’t agree with me. Well, that’s why everyone has his own opinion - I’ve done my best to give a clear, unbiased view based on my experiences with these packages. There can be compelling reasons to buy a different package, as will become evident in the next few articles.
Figure 1: What a mess! Offerings from Mapopolis, Destinator, Pharos, Teletype, CoPilot, Navman, Holux and Garmin
Who are you, anyway, Mr. GPS?
Err, not exactly. I’m just a poor shmo. My wife’s car has a great in-dash system, and I was looking for as close to that performance as possible out of my iPAQ. I don’t have access to Consumer Reports’ test labs, and don’t claim to be an expert. I think it’s safe to say my experiences would mimic someone who has purchased any (or all) of these packages, and used each for roughly five to 10 hours. Of course, the longer you use any of these packages, the more gems you find - maybe a better way to do something, maybe a feature you didn’t realize was present. I read documentation as necessary - if any one of these were my only GPS package, I would have thoroughly read the documentation. Also, I’ve tried to do my homework, and have a fairly good understanding of what goes on with GPS positioning, what the software does, and what the software should do. Finally, I’ve had a chance to talk/write/meet some of the folks behind the scenes, so I have an idea of what’s yet to come.
Why this wimpy disclaimer? Well, to minimize whatever flaming I’ll receive in the discussion forums, of course! Also, because I want to make some points clear. Although I’ve done as much research as I could, and put more than 40 hours into the research and review of these systems, I will undoubtedly make mistakes - these are complex packages, and there is room for errors. Plus, I have tried to obtain some information from vendors which they simply could not provide.
As a general guideline, if I’m reasonably sure something is a fact, there will be no hedging. If I’m pretty sure about something, I’ll make that known to you also. Hopefully any corrections in the forum will be just that - corrections - and if necessary, perhaps any major errors will be changed in the appropriate section to reflect the comments.
Lastly - why is this whacky author being so familiar, with terms like “my experience,” “I saw,” etc. - well, dear reader, while not the most professional way to write an article, I do believe it is appropriate. For all intents and purposes, you’re driving along with me to my home and office. And you didn’t even chip in for gas, so I think we can skip a few formalities, don’t you? Okay, now to the heart of this intro:
What exactly is GPS and NMEA?
GPS stands for Global Positioning Satellites. A GPS receiver essentially picks up a radio signal beamed from three or more of the 24 orbiting GPS satellites the U.S. Department of Defense was kind enough to launch into space for a mere (Dr. Evil voice) $12 billion dollars. By measuring the time it takes for the signal from each satellite to reach the receiver, the GPS unit is able to calculate the distance to each satellite, and ultimately provide latitude and longitude coordinates of the receiver, typically within 15 to 100 feet for civilian use. NMEA is the National Marine Electonics Association, and the NMEA 0183 is the standard protocol interface. Don’t worry, you won’t be tested on this, but at least in theory, any receiver that is compliant should be able to export to compliant software. The receivers output information in text, and the software reads that text and easily translate the position with all the hard location number crunching done by the receiver. In English, you should be able to use compatible software (from other manufacturers) with your hardware.
If three Satellites are Good, and four are better, what about 12?
Most receivers can track up to 12 satellites at once. The Digitraveller can track 16. When your receiver picks up three satellites, it knows your latitude and longitude, i.e. where you are on Earth, and your software can operate in 2D (two dimensional) mode, which is fine for driving. Locking onto a fourth satellite gives you altitude, which is just a curiosity in a car, but pretty useful when flying (bearing in mind the error rate, discussed below).
Your receiver will attempt to lock onto as many satellites as it can. When it has a lock on three, it begins transmitting your coordinates to your software and you’re in business, unless your software requires a 3D fix. It is my understanding that more than four satellites is simply overkill - it does not result in greater accuracy, but it simply allows your receiver some backup data in case a weak signal is lost. The exception may be Garmin - the specs on the StreetPilot III imply it uses data from all 12 satellites at once. The unit has demonstrated (through its own diagnostics) accuracy that varies according to conditions, but at one point it told me it was accurate within 15 feet - sweet! If anyone has information which differs, kindly mention it in feedback - the vendors I have had contact with know their software far better than their hardware.
Just who is NavTech?
Navigation Technologies (NavTech) is an impressive company. All the North American factory installed car navigation systems use NavTech. They also supply mapping data to on-line sites including www.mapquest.com, etc. These are the big boys.
Some packages use data other than from NavTech. I have yet to find any major discrepancies (but have found a bit which will be mentioned in the reviews). Obviously, if NavTech missed a road or incorrectly classified it, you’d expect all packages with that map to have those flaws. I think it's reasonable to expect the data to be accurate to within two years. Huh? I expect a two-year-old road to be on the map, I don’t expect a one year old road to be present.
The mapping information is incredibly complex. Per NavTech, each road segment has an incredible 150 attributes, including turn restrictions, speed limits, number of lanes, one or two way, height restrictions, lane dividers, and about 145 or so things I can’t think about. The software is only as good as the maps. You would expect all packages using NavTech to get the same results, but they don’t, and that’s where the real problems lie, as we’ll discuss in the individual reviews.
What’s the POInt?
Just about each mapping package includes Points Of Interest. Each seems to come from a different source, some include phone numbers, etc. Just like roads, it’s reasonable to expect a lag time from when a business is established (or closed) until that data is reflected in the software. Figure a two year lag time, a number I pretty much made up, but I think it’s about right.
The packages differ in what’s included with their software. To my knowledge, www.mapopolis.com is the only vendor to charge separately for Points Of Interest. At $25 for the entire U.S., it's well worth it.
I would like to note, for virtually any of the systems, do not expect many of your favorite strip malls to be listed - that also includes their addresses. Most programs will treat their address as if they were actually on the road instead of in a giant parking lot. That means the ability to pick a location from the on screen map may be more important than you would have initially thought.
How does a car’s built-in GPS system differ from a Pocket PC’s?
Well, aside from about $1,800, my reference system is my wife’s Honda Odyssey, with the top rated GPS system made by Alpine. Her GPS is augmented with a dedicated DVD player, gyroscope and wheel sensors. The wheel sensors help ensure accuracy and can compensate for situations when the signal is lost, such as in a tunnel. The gyroscopes (solid state, not the spinning tops you put on a pencil as a kid) allow the system to know when the van just made, say, a right turn, allowing the system to calibrate to the road.
A handheld GPS receiver potentially has a smaller antenna than a vehicle’s. Also, there are no wheel sensors, so a lost signal is fatal to positioning, unless an algorithm attempts to guess the vehicle's location based on prior speed and direction. Finally, I am not aware of any handheld GPS receiver with a gyroscope, which I believe is a good thing, as the Pocket PC’s position is calculated based on the difference between the current location and the prior location, regardless of whether the Pocket PC is flat or rotated, making for potentially more accurate Pocket PC readings.
As a quick example of how a Pocket PC’s receiver calculates speed and position, think about standing in a spot, shouting, and then moving to another location and shouting. While the GPS receiver “receives” instead of transmitting/shouting, it does calculate the distance between the current location and the last location (say, one second ago), and also the direction between the two. Using simple math (not so simple for me) software can calculate your position and speed.
The three elements of a Pocket PC GPS Navigation system
Obviously, we need a receiver, which can come in several forms - a detached unit, such as Radio Shack’s $99 Digitraveller which has separate electronics and plugs into the serial port, a sleeve such as the Navman which functions in lieu of a CF jacket, and a CF card receiver which plugs into the CF slot. New entries include the family of Bluetooth GPS receivers, which are not attached to the Pocket PC. A Bluetooth receiver actually transmits the GPS information to the Pocket PC via Bluetooth, opening up some different possibilities as explored below. (Talk about misnomers - a Bluetooth “receiver” receives satellite signals, but then transmits data via Bluetooth - still, it sounds better than saying, “Bluetooth Transceiver”).
In addition to the receiver, there need to be two aspects of the software to make things work. First, there has to be the database that has the information of where things are - here’s a road, there’s a lake, and there’s a landmark or restaurant. Second, you need the software to make it work - the software must make the map usable, and more importantly, for navigation it must calculate the route which is the primary function of navigation software.
The general installation involves loading software into your PC, loading software/drivers onto the Pocket PC, and finally selecting the map area(s) you wish to export to the Pocket PC. Each vendor has a different method of exporting the data. While one vendor may let you download each county individually, another may require you to download 40 megs at a time, which could include several states.
More Errors than Ted Kennedy
Most of the receivers state an accuracy of roughly 10 to 15 meters 95% of the time. That means, most of the time, you will be off by 45 feet, and the rest of the time, you’ll likely be off by quite a bit more (and once in a while, even more accurate)! Shabby electronics? Not at all - these things must calculate radio signals coming at the speed of light. Each receiver has proprietary algorithms to account for atmospheric distortion, reflections from trees, buildings, your neighbor’s dog, wind turbulence, your windshield, etc. What that means is you have to have the right expectation of the software, which must operate under the assumption that the data it's receiving is faulty. Even the best software may think you’ve turned when you haven’t (but should correct in a second or so), and can tell you to turn in 100 feet when it is really 50 feet or 150 feet. For the most part, roads are not so close together that the error is significant, but it is something to be aware of.
Lastly, you need to hold your beloved new navigator. I will post a review of mounts when completed, but I will say this: it is far more useful and gratifying to have your Pocket PC securely held in a suitable location than to drive with it on your lap. Trust me.
Glance-O-Rama
While driving, you obviously can’t stare at the display (something about keeping your eyes on the road). There is definitely a difference between how you use these programs while at home, or while driving.
While your vehicle is in operation, chances are you will become adept at speed reading/glancing at your display, probably in ˝ second bursts. Glance at the display, drive, repeat. There is just so much information you can get in ˝ second (maybe closer to 1/4 second?) During those quick glances, very often the map information will be relatively useless and you’ll want to rely on verbal prompts, and possibly arrows and/or words which visually cue how you’ll proceed. When you use one of these solutions, you’ll likely want to thoroughly familiarize yourself with what you’ll see while driving. Pharos and StreePilot III are the only packages with a simulation mode which let you see your route, turn directions, signals etc. from the comfort of your home (or parked car).
Finally, a quick warning- use common sense when you look at your Pocket PC or set up the routes in the car - simply pull over. The display, whether on a Pocket PC or in dash navigation system, can be distracting, so be smart and spend time playing with the features until you are proficient. Some of the packages have driver/passenger mode, so the driver sees less distractions and has an easier time of things. I am an accident lawyer by trade, and not looking to pick up new business from Thoughts readers! During these tests, I had no less than three near accidents - twice while my wife and baby were on board. The scary part? I was not looking at the GPS displays at the time - I had looked at the displays a few seconds before, and was thinking more about what I had seen than about what I was doing. Okay, no more lectures.
Which hardware is best?
We’ll cover hardware choices in the next segment, “GPS Hardware Review” and also discuss some general mounting guidelines and suggestions. Following that, I’ll explain the test routes and methods used, and show some screen comparisons. Then we can finally get into the heart of these reviews!
Conclusions
I hope you found this introduction informative and not too boring. These few introductions are necessary so you can make an informed decision of which GPS package, if any, deserves your hard earned cash. Although I've spent hours with the hardware, I need to try it in the harshest environment I know, other than by my cats' litter box: the steel canyons of Manhattan. So long for now!
