Vehicle-mounted GPS units

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Do you use a GPS while driving?

Frequently
12
33%
Occasionally
17
47%
Never
7
19%
 
Total votes : 36

Postby Teresa » Dec 4, 2007 9:10 pm

Garmin Etrex Legend in the woods. Mapquest or aaa.com on paper for the car. AAA online triptiks are the major reason for being in that group.

I'm always driving off to strange clients houses in towns I've never been in. Some of these places don't have cell service yet, and are down in hollows where GPS doesn't reach. Internet Paper is good.
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Postby tncaver » Dec 4, 2007 9:48 pm

I'm glad I don't have to compete against the Chimpanzees
too.
But I do like the accuracy of the GPS units in the middle of
the boonies.
Last edited by tncaver on Dec 4, 2007 9:52 pm, edited 1 time in total.
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Postby NZcaver » Dec 4, 2007 9:49 pm

Hey Teresa,

Like you, I've been a devoted Mapquest-printout follower for years. I'm planning to break out of the paper habit with a new GPS!

Regarding reception in hollows etc, I'm impressed with how far GPS units have come in terms of improved receive sensitivity and faster signal processing. Some of these units now even have a "dead reckoning" option for navigating underground - ie navigating through Boston's Big Dig. Not a priority for me, but I can see where some might find it useful. One feature I do like with some of the newer units is the spoken street name announcements.

If you live in one of the 50 busy cities where live traffic info is available, and you don't mind paying the subscription, the traffic feature might be useful. But for me this is another non-priority right now, just like an MP3 player and the Bluetooth handsfree feature. So as most of you probably know, many of these units - even the cheapest ones - come with literally millions of locations for stores, restaurants, gas stations, municipal buildings etc built in. I found it amusing reading some reviews and buyer feedback that exhaustively discusses the finer points of the "cuisine guide" in their chosen GPS. You guessed it - also not a priority for me. But I guess I could grow to appreciate having this as an option. Maybe.
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Postby NZcaver » Dec 9, 2007 8:02 pm

Update - my GPS arrived last week, and I'm pretty impressed with it. The unit I finally chose (after much deliberation) is a Garmin Nuvi 260.

Image

This is not a review (yet), but here are some features that contributed to my decision:

Garmin has a good reputation
This model has North American mapping including Alaska, Hawaii, and Canada (although Canada street mapping is less detailed than US)
It gives you spoken directions, including the actual street names
The database includes the locations of 6 million points of interest (restaurants, hotels, etc), with phone numbers and addresses
The unit will recalculate your journey using an alternate route if you deviate from the original track it created
The screen is bright and easy to see
The touch screen user interface is simple and intuitive
The price was right (retails around $400, now on sale in stores around $350, and I got mine from an online store for about a hundred less than that)

This unit has an SD card slot and USB connector, and includes a photo viewer, world time clock, calculator, and currency/unit converter. Not big necessities for me, but I might occasionally use them. It does not include a traffic condition receiver (which I mentioned previously is not a priority for me because I'm seldom commuting in traffic), nor an MP3 player, a bluetooth handsfree speaker for your phone, or an attachment that cooks breakfast. I can probably live without any of the above.

Thank you to those who provided advice. Feel free to continue contributing to this thread if you wish.
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Postby KENTO » Dec 11, 2007 2:28 pm

How are you techies gonna get around when the fuel runs out and lithium batteries are hoarded by the government? :woohoo: :laughing:
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Postby fuzzy-hair-man » Dec 11, 2007 5:28 pm

KENTO wrote:How are you techies gonna get around when the fuel runs out and lithium batteries are hoarded by the government? :woohoo: :laughing:

The horse knows the way. :nana: :laughing:
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Postby YuccaPatrol » Dec 12, 2007 8:48 am

I've used GPS since it was first made available to the public and have owned more than 10 units over the years.

I recently bought a Garmin Nuvi 200 for my wife. I specifically chose the CHEAPEST one they sold because it is the simplest to use, and does not have a bunch of unnecessary non-GPS features to bump up the price and add layers of complexity that are not needed.

Garmin has always been the standard for GPS and I know from personal experience that their customer support is incredible. They once replaced a unit under warranty that I had run over with my car. I contacted them to see if it was repairable and told them that it was quite crushed. They said to send it in anyway and they would see if it could be repaired for a fee.

They sent me a new unit the next week.

If I didn't know about the customer service, I would probably buy a Tom-Tom which has some clever and interesting features (user-modifiable maps), but Garmin has me hooked for life.
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Postby Squirrel Girl » Dec 23, 2007 10:30 pm

When GPS units first came out, I thought, "I don't need one, I can read a map." But eventually I bought an Etrex Legend. It's great because I can make maps of my bike routes, and put waypoints in for cave locations, etc.

Now I'm going to use it to get elevations to enter into my weather meters to calibrate the barometric pressure.

There are many ways I prefer maps, but the gizmos can do things that are just more convenient.

I then saw no reason to get a GPS for my vehicle. I can read maps afterall. But I went downtown the other day with someone who had a GPS. And I have to admit that there's something nice about getting directions around cities where I don't generally know my way. It's very hard to read one-ways on a map while you're driving. The voice-directions are pretty convenient.

THEN, the last few days, my nephew stayed at my house. He works for Teleatlas and drives around roads mapping them, and the data gets sold to Google and Mapquest, etc. His company just got bought (or is about to be bought) by TomTom. So now I'm thinking about getting a TomTom.

I still love maps. Even if I get a car GPS, I won't toss my atlases. But that doesn't mean GPS's don't have some use.

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Postby NZcaver » Dec 23, 2007 11:02 pm

Squirrel Girl wrote:Now I'm going to use it to get elevations to enter into my weather meters to calibrate the barometric pressure.

One word of warning - generally speaking, the altitude is the least accurate feature of GPS units. Unless you have access to a professional survey quality GPS with antenna or know something else which I don't, I'd suggest against using consumer models to calibrate for altitude.

I still love maps. Even if I get a car GPS, I won't toss my atlases. But that doesn't mean GPS's don't have some use.

Yep - as far as being an "aid to navigation" they've come a long way since I first played with one back in the mid-90's.

Cool photo, by the way.
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Postby Squirrel Girl » Dec 24, 2007 6:52 am

NZcaver wrote:One word of warning - generally speaking, the altitude is the least accurate feature of GPS units. Unless you have access to a professional survey quality GPS with antenna or know something else which I don't, I'd suggest against using consumer models to calibrate for altitude.

But of course! The altitude is *not* accurate. But if you see how much change there is in pressure relative to the change in altitude AND the precision of the pressure, you'll find that the GPS is close enough. If I have access to better data, so much the better, but the GPS is within spec.
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Postby tncaver » Dec 24, 2007 8:07 am

GPS units for the general public do not have extremely accurate elevation
readings. Although the Etrex Legend has an elevation correction
function, it can still be off by 10 to 20 feet. However, if you plot your
coordintates on a paper topo map the elevation is pretty accurate
because the coordinates are very precise these days.
A vehicle mount is available for the Etrex Legend. Although I think it
would be very distracting to use it while driving. However, a passenger
could use it while driving and give voice directions.
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Postby Squirrel Girl » Dec 24, 2007 9:02 am

When I went to India earlier this year, someone else had a different Etrex than I do. His gave better elevations than mine. When I got back, I checked the web, and sure enough, he's got something inside his that does do better elevations. Too bad I can't remember which model he has. He didn't have maps in his though.

Maps are great when you know exactly where you're going and you buy them ahead of time. If you're doing reconn or relying on others for suggestions and decide later where you go, you won't (well *I* won't) have all those maps pre-purchased, just in case. A GPS is really handy in that case. Plus if you let it run for a while, you can average the results and get a better answer, even if it's not perfect. Again, for my weather meters, it's still within the precision of that instrument.

I wouldn't even consider trying to drive around navigating with my Etrex Legend. The screen is WAY too small. I virtually never have a passenger with me, so that wouldn't help either.

Another problem with maps and navigating is that some people who read with reading glasses can have an extremely hard time reading maps--especially at night. A GPS with a big lit screen and voice directions would be way better.
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Don't trust Topo elevations

Postby Jep » Dec 24, 2007 10:17 am

I deal with coordinates daily as part of my job. I agree that you cannot trust GPS units for accurate ground elevations. I even get to play with a Trimble TSC1 whenever I want. The only way I can get accurate ground elevations with it is to go to a known bench mark and calibrate it, and I have to do it every time I turn it on.

However, from the tower work I do on behalf of my clients, I clear a lot of towers with the FAA. Even if I have a survey to 1A accuracy in my hands, the FAA questions me if my ground elevation doesn't match what they see on a topo. 1A accuracy is to plus or minus 20' (6 meters) in the horizontal axis and plus or minus 3' (1 meter) in the vertical axis.

So, the truth is, topos are not always accurate for ground elevations. In fact, here in Greenbrier County, they do not have all sinks on the topos that have obviously been there for years and are a large enough land features to to have been seen when they did their aerial updates in the last 30 years.

And I remember one site in Lancaster PA that the survey was over 80' higher than the highest contour line on the map. I sent the surveyor back and he came back with similar results. I then went into the field with him, watched him calibrate his unit and my Trimble and we both came up with the same GE. It was a slow day, so I was able to make the commute from Harrisburg to the site and still be back in time for lunch.

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Postby Squirrel Girl » Dec 24, 2007 11:59 am

OK, just to provide data. I changed the elevation in my weather meter by 7 m (about 20'). It changed the barometric pressure reading 0.7 hPa. The accuracy of the unit is 1.5 hPa. So I maintain that the GPS is good enough for this particular purpose.
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Postby Squirrel Girl » Dec 26, 2007 7:04 am

NPR had a story this morning on GPSs being the hot gift this Christmas:

http://www.npr.org/templates/story/stor ... d=17611103

They talk about how your GPS can now give you audio tours of things you drive by on the road. I predict this is yet another place where cave locations will end up.
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