Mapopolis Inaccuracy

[+EarlyMorningHours]

I don't know how many versions this has been going on or if it has always existed but what I am about to describe seems a little odd. I'm using an iPAQ 3975 upgraded to PPC2003 with a CoPilot bluetooth GPS and Mapopolis V4.33. My wife and I did a multicache yesterday, "The Bookworm Exchange" by -=(GEO)=-, in which the first two finds were simply coords to the next. It was in the 20's yesterday in the Buffalo, NY region and at first I was thinking that possibly this error was an effect of the cold temperatures on my iPAQ but last night I was able to replicate the problem in my 70 degree home.

 

This was a cache we were coming back to since we had been stumped earlier. I was being extra careful with everything this time because I really didn't want to walk away empty twice. I entered the coords into Mapopolis, named the landmark "Part 2", and went back to the map. I then tapped on the pink circle with white X and it showed the name, "Part 2", followed by the coords, which were not what I had just entered . I proceeded to delete this erroneous waypoint I had just created and repeated this whole process at least a half dozen more times. Every time I had something a little bit different. The coords aren't off by too much; usually only 2 or 3 ten thousandths. But on three star and up caches this could obviously be problematic.

 

I use the gpxtomaplet utility to convert my GPX files to Mapopolis' mlp format. So I decided to look at some caches in Mapopolis and compare the coords to what is posted on Geocaching.com. Sure enough, same spread, 2 or 3 ten thousandths. So the gpxtomaplet converter doesn't seem to be the problem since I get the same error by entering manually.

 

So now its all starting to come together in my mind. Most caches are hidden in such a way that with enough experience under your belt you just need to be in the general area and you'll find it by looking in the obvious spots. With the harder caches I had been resorting to GPS Tuner V2 to average my way to the cache. This was probably partly due to the fact that Mapopolis had me off by a couple hundred feet. Has anyone else noticed this problem?

[+-=(GEO)=-]

Yup, I have observed the same thing. Since I don't use Mapopolis for caching proper but rather for navigation / research, it never bothered me too much, except when I use it to validate the puzzle solutions where precision matters. It must be very annoying for you though.

 

Regards,

Fabien.

[+EarlyMorningHours]

A couple of weeks ago we were trying to find a new cache (which has since been archived) that involved doing some binary math and then coordinate conversion. Simple stuff if you're a computer guy. Well, looking back on it now I know why we ended up on the docks of a yacht club instead of the the bridge about 300 feet to the south!

 

In fact there's a particular 5 star I might have to go back to real soon...

[+4agers]

Wow, thanks for pointing that out. I've been using mapopolis to navigate me between caches for a few months now and love it! I always enter coordinates from gpxsonar and not mapopolis so I haven't had a real issue.

 

I plan on upgrading to a bluetooth gps soon... then this will be an issue.

 

I've taken the liberty to ask the question in the Mapopolis forums... here

Edited December 8, 2003 by 4agers

[+robert]

I've taken the liberty to ask the question in the Mapopolis forums... here

Definitely a good idea. Lamar over there can help.

[+JeepCachr]

Did you ever get an answer to this? I'm using mapopolis with my fortuna clip on blue tooth receiver and an Ipaq.

 

I've only looked for one cache but it got me within 10 ft. of both stages. I'm wondering if GPS Tuner or Navigator II will be any more accurate or get me any closer.

[+CacheCreatures]

Interesting indeed. I use a Fortuna CF GPS on my Dell, and Mapopolis is the only app we've ever needed to locate the caches. (We've also hidden a few using this setup with no issues.)

 

I have noticed that, while entering coords manually, they will usually translate to the map 1 or 2 1000th off. But in real world terms that has equated to about 7 feet; never enough to be of concern.

 

Are we thinking this is an issue specific to bluetooth gps's?

[+EarlyMorningHours]

JeepChr,

 

I never did get an answer, but then again I never posted anything over at GPSPassion. As CC stated though, you're talking about 1 or 2 one thousandths, so it probably isn't a huge deal.

 

I've been using GPS Tuner for quite some time, but I'm not all that pleased with it really. The averaging routine that the program uses needs to be updated so that it drops individual readings that are too far out of whack from all of the other readings. One problem is that starting with V2.5 he made the standing / walking setting automatic. I preferred it as a manual setting, which I believe would better accomodate stripping out wildly inaccurate readings.

 

CC,

 

I don't believe this has anything to do with BT GPSs. You could verify this by running Mapopolis without your GPS at all. Enter some lat / long and see if they are in fact what you entered.

 

I'm beginning to find out that in some cases the most important thing is how accurate the coords are that are supplied by the cache owner. You could be using $3000 differential with post processing and it wouldn't help a bit if the owner posted coords that are 15 meters off. The flip side to this equation is the owner could have spot on coords, my GPS could get me to say within 3 meters, but if its an unusually devious hide, the GPS won't help. I'm completely stymied on part 4 of a 5 part cache. The owner has verified for me that part is in fact there and that the coords are ok. He's just a sick and demented cache placer

Edited March 22, 2004 by EarlyMorningHours

[+NightPilot]

Keep in mind that Mapopolis was never designed for geocaching. It's designed to route you via streets to an address. If you want to geocache with your Palm, try CetusGPS. It's much more oriented toward geocaching, and works much better. Mapopolis will get you to the parking area, and that's all it was designed to do. Then switch to Cetus for the walk to the cache. Cetus in its latest version displays the cache pages, and you can upload the waypoints from several programs.