GPS Wierdness

[stiles watson]

Put together a 70 mile trip to get acquainted with my DeLorme and Street Atlas today. Cruised along nicely. Turned off the freeway an exit too early. GPS recalculates automatically. Cool!! The closer I would get to the destination, the larger an more detailed the map would become. Cool!!

Then all of a sudden, the green arrow veered off the road line on the map and ran parallel to it. Then It started announcing that I was off the path and started suggesting alterations of the route. Had I not known where I was going, I would have been in a pickle. NOT cool!!

Now tust level is shot to blazes. The beginining and ending points were full addresses. Now I am confused.

[CountryGuy]

Stiles

At home in Lenawee County we were testing GPS as well, places we knew. On highway going north, come to stop sign, road keeps going, but GPS wants us to turn left, go 200 feet, then turn right. I told Al, cool, the GPS must think I need to go re-read that cemetery (one of my little pet projects, reading and helping local genealogy club publish into book form.)

Problem was, that the road did not turn, but went totally straight.

We have found that campgrounds may be hard to input as an address (at least some we have tried so far). GPS does not recognize the address, AT ALL! Other campgrounds have no address (Makes me think the 2 CD set of campgrounds someone was talking about the other day might be nice to have??

To find one campground, I had to get out my laptop (streets and trips) and find the town, then zoom in and out till I found where the campground should be. Ended up setting a way point to the town for GPS, kept laptop on my lap (whoooeee, those babies get warm!!!) and using it to get us to the campground.

OH, we have a Garmin 2610.

I think Steve R has said this before, seems you need more than one system. SIGHHHHHHHHH

Carol

[DHenry]

Carol, have you ever updated your Garmin 2610? If you go to www.garmin.com and choose updates and downloads you can download the current changes they have made to the 2610 and it should help correct some of the errors that it makes. Good luck.

[CountryGuy]

DHenry,

I will ask Al, the unit is rather new, but I will ask him. Thanks for the hint!

Carol

[sreigle]

Stiles (and Carol), there is nothing wrong with the GPS or the software. It's the maps. They all use government maps and sometimes the roads are off either because someone drew the map incorrectly or the road has changed since the map was drawn. What you experienced is exactly why I turned off the automatic backontrack feature. Now if I need it to get me backontrack I just click the backontrack button. Turn that off and it's not nearly so disconcerting. By the way, our old neighborhood where we had our last stick house had streets on the maps all screwed up EXACTLY the same way on the official city map, on Street Atlas, and on Streets and Trips. Exactly the same.

One thing you said that I didn't know is that the closer you get to a turn the more detail it shows. Maybe I start out with the map at too detailed level to see this. Which magnification level did you start with? I'd like to try that. I usually start with 13 or 14. Thanks.

Carol, what software are you using the software with? I use find with addresses in SA and it usually finds it just fine. Occasionally there's one not there but most of the time it finds it.

[CountryGuy]

Steve,

Garmin software. Came with the 2610. Stand alone unit. We get that closer view when we get close to a turn or a way point, that is kinda neat.

I have on the laptop, Microsoft Streets and Trips 2004?? Shoot, pulled it up, does not say, but does say 11. blah blah blah , lots of numbers. It will not find the campground in Watson Illinois either (the one I could not find on Garmin). That proves your point that they are all using the same basic data.

Another thing I noted while driving down, that NOT all services available along the road are on the data base. Saw a lot of gas stations, truck stops, etc, that were not included in the data base. Sure would be interesting to know who picked the data included, and the perameters of the decisions.

Now, here is something that is fun, you are driving along on an interstate. Now, you come along an area where they are "rebuilding" the expressway, maybe they have moved the road over a few hundred feet. GPS does NOT know this of course, and the "voice" goes bererk, screaming, OFF COURSE, RECACULATING. That will catch your attention!

Did pick us a nice flat route from Tipton to Texas, hardly any hills! Fastest route. Did include some really rocking roads tho.

Be nice when you could say, pick the fastest, less rocking and rolling route! HA HA, dreaming on, eh??

Carol

[sreigle]

Carol, turn off the automatic backontrack! The automatic option is new with the 2005 version of SA. At first I thought I'd like it but for the reason you and Stiles found out, I turned it off. I'll click the button if and when I want it to get me backontrack. But I also have auto calculate turned off (as opposed to auto backontrack). I don't like it recalculating at every change I make in the route when planning a trip, especially when we're talking a 1200 mile trip. Takes too long. I'll click the calculate button when I'm good and ready.

Carol, in S&T I think you can get the longitude and latitude coordinates of the cg. You could enter those into the garmin software. Like you, I find no package has everything. I find more CG's in S&T, like one of the folks said above but I find more walmarts and other stores in Street Atlas. And neither has all of them. I'm not sure where they get that info anyhow.

[Dave e Victoria]

A couple of points here for those of you really interested in GPS.

1) The map reading facilities of GPS products are still very new. When I was with Sperry/Honeywell, we were building state of the art electronic map systems for the most advanced fighters of the time (F/A-18 and AV-8). This was only 15 years ago and the systems cost nearly $150.000 per copy. Total data storage was about 600 megabytes on a glass CD size disc. We've come a long way babe. Things were evolving then and they are still evolving today.

2)Map technology or cartology is an art (as in painting) For example, If you look at a map and see a major high way depicted on an atlas it is about 200 times as big as it actually is. Moreover, the route tends to smooth out curves and turns. As you get to a higher and higher resolution, these details get corrected if the details are known. The fact is that as GPS has come into play and we get to higher resolutions we are finding a whole lot of things are not where we thought they were to begin with.. This is not part of the art- just simple inaccuracy and error. (The old engineering tongue in cheek axiom: accuracy is inversly proportional to resolution)

Manufactures such as Garmin are in a constant stress trying to get the most accurate data to support new navigation features for their products. Unfortunately, the map folks have less incentive to get things straightened out. I suspect we will be in a turmoil over these different objectives for years to come.

Now, here is other real trivia for you.

a) the map data over the former Soviet Union were digitized from satellite data and are, for the most part, more accurate than the data over the remote parts of the US. (although, they didn't care much about actual addresses). This was to support the TERCOM systems which guided our cruise missles.

b) some map data are specifically inaccurate on purpose. Foe Instance, the Chinese government map data for Beijing airport is in error by about 15 miles. This is because the Chinese Government doesn't really wnat any on to know where it actually is. Every airplane flight management system flying into China has to carry this correction in a NOTAM( notice to airmen) data base. How would you like to land in the fog in that city. Scarry huh!!

[CountryGuy]

Dave,

Another good reason NOT to go to China?? (JUST KIDDING) The fees to float Montana there would be a bit out of the Stevens budget levels!

Thanks for the insight, it was VERY interesting!

Had another go around with Garmin today, not entirely satisfactory. Maybe as we adjust to Garmin, we will think better of the system???

Cheers, Carol

[Parrothead]

I agree with Dave. I have bought government maps to load into data bases to route buses or for other demographic purposes. They are expensive and only about 90% accurate. It was troubling to me because I had little kids waiting at the bus stop. We could fix them in the databases I was using but it was very, very time consuming. Can you correct or add to the maps in the GPS software?

[sreigle]

Dave, thanks for a great explanation!

Carol, I meant they all use govt maps but business shown and their location, I don't know where those come from and they do have different levels of this it seems.

Parrothead, I know that in Street Atlas you can edit the roads and add new routable roads. I found a (just one so far) freeway onramp that was shown as one-way in the wrong direction so changed that. I also back in SA2003 drew in the corrected neighborhood streets in our stick home neighborhood. In the SA2003 and SA2004 versions those changes would be there from one use to another when I used the same map or loaded the same road edits. But for some reason in the SA2005 version it sems to lose these changes when I shut down the app. Not saving the changes I guess. I have not checked DeLorme's site yet to see if there's a fix. I don't use the edits very often so don't worry much about them sticking around. But, yes, you can edit the roads.

[CountryGuy]

Short update

Al checked and even downloaded latest software (which we believe was on the unit, but is for sure now) from Garmin.

Found out there are MANY MANY MANY more attractions, etc. on the computer version over the loaded unit version. Now, there is every possibility I misunderstood this yesterday when he was working on it, as I had my own project going on a different computer and during some of his ranting and raving I turned off my listening devices (my ears! ).

He did find a number of "stops" and "attractsions" we want to see while here and loaded from the computer to the Garmin. His statement was, this is easier than trying to do on the Garmin while in the truck.

The learning curve continues.

Carol