GPS comparison

StG58

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This Christmas is GPS Christmas for the oldest Daughter and the Wife.

We do a lot of outdoor activities in the Coast Range and Cascade mountains of Oregon. Wheeling, camping, hunting, hiking & etc. I currently have a Garmin 62st with the 1:24k chip installed. I trust it, and use it constantly. Tracks and waypoints are downloaded to the laptop and analyzed in two different mapping programs, depending on what I am trying to determine.

The wife and I picked up a Garmin 64s and a Garmin 600 Oregon for about $200 each this last weekend. Couldn't decide which one to give to the Daughter, so we went up into the hills to thrash them out a little.

The three GPS units in the test were the 62st, the 64s and the 600. Put fresh, fully charged Ni-MH batteries in all three. Moved the 1:24k map chip into the 64s, and booted all three up in the house. The 62st found it's satellites and got a lock on it's position in about 30 seconds. The 64s took about a minute and half to find satellites and achieve a position lock. The 600 about two and a half minutes to find satellites and achieve position lock. The 64s and 600 were brand new, and were starting out with no idea where they were. This would be the equivalent of driving several hundred miles and then turning your GPS on.

Once a lock was achieved, we let them run for about 15 minutes or so to see how much the position wandered. The 62st and the 64s were similar in this regard. Both reported an accuracy of 32 feet, and the track was about 32 feet in diameter. The 600 reported an accuracy of about 75 feet and the track was about 100 feet in diameter.

We threw a couple of pistols and some gear into the Jeep and headed out to the coast range for a couple of hours. All three tracked reasonably close to the road on the map. Close enough, anyway. Trying to get a map and a GPS to exactly match ground truth is a fools errand anyway. With survey grade gear you can come really close, but this is consumer grade gear...the maps we have access to will always vary from ground truth in any event. (another discussion for another time)

We arrived at our destination without incident, and commenced testing the wife's new revolver out with various loads. When we were done with that task, we tested the GPS units in the clearing. This test involved setting a point, letting the GPS units settle on that point, and marking it.

We then wandered to the far side of the clearing and, called up the marked point and told the unit to "Go To" that point. The 62 and the 64 performed about the same. In this instance, the addition of GloNASS reception on the 64 made no difference in it's ability to navigate back to the marked point when compared to the older 62. They both announced that they had arrived at the marked spot within about 20 feet of the actual marker. Zooming in on the display allowed us to get closer to the actual mark. Giving the GPS time to "settle" decreased the distance from the mark to the GPS unit. So far, so good on that test. I can live with getting within 20 feet of the mark. The 600 announced that it had arrived at the mark while still a good 75 feet away. It never did settle enough to allow us to get closer than about 25 - 30 feet of the mark.

We loaded up, changed the 24k chip over to the 600 and headed back. The 600 displayed an interesting phenomena. It would loose signal as we drove through the canyons and under heavy tree cover. It would draw a straight line from it's last know position to it's next know position, and then "curve match" the road in a few seconds. The straight line would "snap" to the road. That was a little disconcerting. I'm guessing that the processor was making assumptions about our line of travel, and correcting the GPS track to match. We were only travelling about 25 mph or so.

The 600 is a touch screen, high-zoot unit. There are only two buttons on the side. Power and mark. The rest of the input is through the touch screen. Does it work? Yes. It even works with gloves on. But, we found several issues with using the touch screen. If you are going to throw it in a pocket or a pack, the screen must be locked, otherwise, you will never know what screen it will be on when you pull it out. It is difficult to use one handed with gloves on. The wife could only one hand it in her left hand with gloves on. She has small hands. The accuracy of input goes out the window and things like wiping water drops off the screen cause unexpected results.

The 62 and 64 use the same input method. Buttons under the screen. Screen selection and input were old school, but worked right or left handed with gloves or without. Naming waypoints was a pain, but do-able. Naming waypoints on the 600 was easy and fast.

All three units can connect to a tablet or laptop through USB. The 62 and the 64 have the ability to be connected to an external antenna. All three support internal microSD cards for mapping chips. All three have plenty of built in memory for additional mapping products. The 600 and the 64 support GPS and GloNASS satellites, though GloNASS was turned off by default on the 600. All three can store more tracks and waypoints than you are likely to generate in a year.

The bottom line is the 64 and the 600 are both good units. They will both do what needs doing. The wife and I prefer the 62/64 and the Daughter is getting the 600 for Christmas. We will return the 600 if she doesn't like it and get her a 64s if she wants one, and she probably will.
 
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Nice write-up / review!

Here's a good question: With smart phones becoming as advanced as they are, I've noticed that Garmin makes apps for the iPhone and Android phones. Do you see any reason why a dedicated GPS unit would be better than a smart phone using one of the Garmin apps?
 
The antenna is the key. The performance difference between the 62, the 64 and the 600 basically boils down to the type of antenna that each has. (ignoring the touch screen) The 64 has an antenna optimized to receive GPS and GloNASS signals, while the 600 has an antenna that is compromised for making the unit more streamlined and slightly more compact. I think, but can't prove, the optimal navigation setup for a Jeep would be a tablet computer and a GPS "hockey puck" receiver. Connect the two through a usb port and you get the best of all worlds. An 8 or 10 inch screen would allow you to see more map, and the dedicated hockey puck receiver would be optimized to receive the weak gps and GloNass radio signals. The families criteria for selecting a gps unit is a little different than most. Our ground conditions are pretty severe, and our accuracy, supportability and portability requirements are on the extreme end of things. The NI-MH batteries can be charged from a solar panel pretty easily. Same with a smart phone though. I bet the smart phone would do fine, if you can load up high resolution maps, for most people in most circumstances. If nothing else, the smart phone would give you a little bigger screen at the cost of lower accuracy.
 
These units that you have, how do they update? I assume they connect to the Internet and can download newer maps and such?

I've seen that Garmin makes some software for phones (I believe it's around $100). It's very highly reviewed but I wonder how well it would work when you're in the middle of nowhere with ZERO phone reception. Like you said, you'd need some sort of external antenna or something.

For all I know this is indeed possible. I just haven't done enough research to know if it is or isn't. This is probably because I use my phone for GPS all the time, but that's because I'm not in a remote location where I need something other than a phone.
 
What is this update you speak of? LOL Seriously though, around major cities the road network changes pretty often, and updates are important. The further out you get the less changes occur. With cartography, we are interested in four things, Latitude, Longitude, Elevation and Time. (or some variation there of) Basically some things position on the earth's surface and how that changes over time. In the city, things appear and disappear rapidly. Natural features, not so much. A river will change course slowly over time, lakes become wetlands, become meadows etc. Roads get pushed through for a logging operation and then disappear in ten or twenty years. The update cycle for a USGS 7.5 minute map (1:24k) is probably 20 years or more. Street maps go out of date before they are ever published. I get the USGS 1:24 chips for the units and just live with any differences that exist between the map and ground truth. That's life. For software updates on the units, they get plugged into the laptop and the firmware gets flashed once in awhile, usually whenever I get to thinking of it and don't have anything better to do.

On the reviews for the Garmin software, check out how they are being used and by whom. I'm betting that they are being used in the city for navigating the city. Maybe the occasional jaunt into the country. Those mapping applications have and will continue to kill people because they have the wrong information presented in the wrong way for venturing into the pucker brush. It's just a fact of life.

You don't need cell phone reception to use a mapping application on a smart phone. A smart phone has a gps receiver built into it, and the hardware to process that signal is built into the phone. The truly interesting Jeep roads are out back and beyond cell reception. I know I'm getting there when I haven't had cell reception for twenty minutes or more.

You know, we could / should have a discussion on maps in general on this site some time. I actually had a business associate, now deceased, who did some of the first detailed cartographic surveys of Oregon and SW Washington back in the day. It was back in the 1920's and 30's IIRC. The tales he told were interesting and informative, to say the least. A lot of it was done on horseback by two man teams who would be out in the countryside for a week to ten days at a time. The technology has changed a bunch, but those were the base maps that what we use today are derived from. USGS DEM's, 1:100k's, 1:24k's, GNIS database, US Census TIGER/LINE files... The technology has changed a bunch, but all of the base maps that the modern stuff is derived from is based on the cream of 19th century technology.
 
You're right. I didn't think this one out before I opened my mouth. Why would anyone need a map update when they are out well past city limits in areas where it probably takes hundreds of years for any sort of significant changes to the land.

Those Garmin apps are indeed being used almost entirely by city dwellers I would bet. I would however thing that those Garmin apps would have to be just as good as the actual Garmin units themselves even for the areas out in the middle of nowhere.

I was under the impression you needed cell phone reception to use a mapping application. I say that because anytime I am out past cell phone reception areas and I try to use Google Maps or Apple Maps it won't work because there's no signal. That being the case, I figured it required cell phone signal in order to connect to the satellite. Am I wrong?

The idea of maps in general is an interesting one. I've thought about this from time-to-time when I was bored. That at some point in time there were people who had to map out all this land by themselves with nothing but pen and paper. It's one of those things that's pretty amazing the more you think about it. And then to think how far we've come these days where things can be mapped out by satellite imagery... All of that happened so fast it's just crazy.
 
Ahhhh... Google Maps. The cell phone knows where it is, but the map has to come over the cell service. Just like paper maps, you have to carry the map with you to use it. Hence the map chips for the GPS units. You can download the map to your laptop / tablet / cell phone / gps unit, but you have to have the map stored before you loose the cell signal. Did you know that all USGS, and most other map data in the US is public domain? Do a search on USGS maps... The whole world is out there in almost whatever resolution you want. Even the CIA was in on mapping for awhile. NASA has some pretty cool stuff available as well.

Satellite imagery...photogrammetry (image based mapping) can and will lie to you. It does have it's uses though.

I have a software package from the University of Hawaii that let's me do all kinds of cool and useful stuff like putting a satellite image under any map or other spatial digital data set that I want. It's a wonderful way to burn a weekend!
 
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Gotcha. So there must be a setting within my Google Maps app where I can download it so I have it stored before I lose signal. Haven't played around with it enough to know in all honestly.

I figured that map data was public domain. I'm sure at some point it wasn't, but once the public started to be able to buy GPS units something must have changed.

I've burned a weekend or two with Google Earth. You know, just zooming in on places I've never actually been just to look around. It makes the world seem much smaller than it actually is.
 
I don't use Google maps, so I can't answer that. I just pull out the map book and thumb through it to the map I need. The gps tells me where I am. Man, I need to work on my map setup this winter. I'm tired of looking at the world through a keyhole.

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The US is unique in that all US Government map data has always been public. Not so in the rest of the world.

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The US is unique in that all US Government map data has always been public. Not so in the rest of the world.

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Didn't know that, that's pretty cool! Wonder why it's not like that in the rest of the world. Seems pretty silly!
 
Chris, I'm not sure which one or if it's all of them, but some of those GPS apps on the AppStore actually contain maps of the entire USA and once downloaded, don't require Internet/cell service. Programs like Google Maps and Apple Maps need Internet do download the map on the fly. It wouldn't be feasible for a map program to be preinstalled that has gigs of map data.
 
Chris, I'm not sure which one or if it's all of them, but some of those GPS apps on the AppStore actually contain maps of the entire USA and once downloaded, don't require Internet/cell service. Programs like Google Maps and Apple Maps need Internet do download the map on the fly. It wouldn't be feasible for a map program to be preinstalled that has gigs of map data.

I don't think Apple maps allows you to download the map, but I read recently that Google maps rolled out a new feature where it allows you to download the map before you head out so that you don't need to rely on cell phone service. That would be handy if you're in the middle of nowhere.

My only concern is I wonder if the maps on Google Maps would be as good as the maps with Garmin or others? I would have to assume so since Google has probably put billions into Google Maps.
 
I don't think Apple maps allows you to download the map, but I read recently that Google maps rolled out a new feature where it allows you to download the map before you head out so that you don't need to rely on cell phone service. That would be handy if you're in the middle of nowhere.

My only concern is I wonder if the maps on Google Maps would be as good as the maps with Garmin or others? I would have to assume so since Google has probably put billions into Google Maps.

I would want to rely on google's satellite images more so than a garnin or tomtom. Even for off-road stuff it'll zoom in pretty nicely so you know more easily what your surroundings are.
 
I'd put my money on Google Maps being based on Census TIGER/LINE data and USGS 1:100k data where the Census maps are sparse. They may do some of their own mapping, but it's pretty expensive. The 1:100k stuff is already broken out in layers like roads and hydro. Pretty standard in the industry for road maps.

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Tiger/line has road names and address ranges in it, so it greatly cuts down on the cost of producing a map. Place names and things like rivers and mountains come from the GNIS data.

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I'd put my money on Google Maps being based on Census TIGER/LINE data and USGS 1:100k data where the Census maps are sparse. They may do some of their own mapping, but it's pretty expensive. The 1:100k stuff is already broken out in layers like roads and hydro. Pretty standard in the industry for road maps.

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You've gone over my head with map lingo!

So, if you were navigating the off-road areas way beyond city limits, would you trust Google Maps over a Garmin mapping system, or vice versa? In other words, who makes the best maps for navigating the off-the-grid areas?
 
Garmin, or my own custom maps. A paper map book is a really good idea as well. Electronics fail at some point. A compass and a map book.

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You mentioned using your smart phone as a GPS. Here is an interesting device and app combination that has offline texting and mapping. Might be worth a look at $200 a pair.

http://www.gotenna.com/

Also, this seems to be highly rated for trail use.

https://www.gaiagps.com/gallery/

Sorry about the techno-babble about maps. Had a cartography business for awhile when computer mapping was just starting out. Neat stuff and I like to share. I guess the bottom line is that all of the maps that we see available and that we can afford are based on about a dozen public sources in the US. All have known accuracy issues. The USGS 1:24k's are the gold standard for what we do off road.
 
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