Inaccurate Waypoints

 

Can someone explain why some of the GPS POI files that are uploaded are so inaccurate? I'm editing a file of Walmart stores and some of the locations are so off the mark it isn't funny. I'd be ashamed to have my name attached to anything that was so useless.

If you are editing the file

If you are editing the file you downloaded from POI_Factory, then you are wasting your time. Most of those POIs have been adjusted to take you to the front door.

If you are editing files downloaded from Walmart, you should download the files from POI-Factory.

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Frank Nuvi 3597LMT 37.322760, -79.511267

POI's

revrnd wrote:

Can someone explain why some of the GPS POI files that are uploaded are so inaccurate? I'm editing a file of Walmart stores and some of the locations are so off the mark it isn't funny. I'd be ashamed to have my name attached to anything that was so useless.

Are you referring to the GARMIN POI's or the ones from POI factory?

You have to realize that the person who creates and maintains a POI file cannot personally visit EACH and EVERY location.
So the way it is done is to use the GARMIN maps installed in your computer to get as close a location as possible. At least that is how I do it. I may use the Garmin map, MS Streets&Trips and GOOGLE Earth as well. Some commercial establishments have lat/lon on their website but even those can be out.

Having said that, feel free to pay someone the expense to check out all the Walmart locations in all of North America.

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Nuvi 350 long gone, Nuvi 855LMT, Nuvi 2797LMT, 3790LMT passed on to my daughter. Using Windows 10. DashCam with GPS.

Some Examples, please

revrnd wrote:

Can someone explain why some of the GPS POI files that are uploaded are so inaccurate? I'm editing a file of Walmart stores and some of the locations are so off the mark it isn't funny. I'd be ashamed to have my name attached to anything that was so useless.

We would be interested in some examples of locations from a POI file that you think are inaccurate.

For the files that I maintain, the coordinates are set at an "entrance" off the road on which one would likely be traveling. What this permits is an alert to be set when one is driving around. Note that "alerts" will only sound if the coordinates are set to within 30 meters (about 98 feet) of the roadway on which the GPS is traveling.

Company Data can be almost useless

Addresses supplied by the company, can be terrible. I did the KIA Canada file, and got the original addresses from KIA Canada.

I found city names that did not match with the actual suburban names. Street addresses are often out you a huge distance away.

When making a file, creators often have to go to Google Earth and also street view to drag the marker to the actual position. It can be very difficult to do a perfect location.

A mall address might be nowhere near the actual store entrance.

That said, some creators are really anal, about the location and there are some who aren't quite so anal. Most of those responding in this post are in the anal realm and do everything possible to be very accurate.

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NUVI2555LMT, NUVI350

The files were downloaded

The files were downloaded from POI-Factory. For example POI for a store will not show up on a street in the town on Base camp. View the 'item' in Google Earth and the POI will be in a forested area nowhere near a street, road or highway. Google Earth image is within a year, so it's not like the image was from 10 years ago and sprawl has occurred in the meantime.

Contact the maintainer

revrnd wrote:

The files were downloaded from POI-Factory. For example POI for a store will not show up on a street in the town on Base camp. View the 'item' in Google Earth and the POI will be in a forested area nowhere near a street, road or highway. Google Earth image is within a year, so it's not like the image was from 10 years ago and sprawl has occurred in the meantime.

Have you contacted the maintainer of the POI file to revise the error(s)? That's how those of us who do not create or maintain a POI file here can contribute to The Factory's accuracy of the custom POI files available. I maintain no custom POI files but I've offered corrections many times.

Coordinate Errors

revrnd wrote:

The files were downloaded from POI-Factory. For example POI for a store will not show up on a street in the town on Base camp. View the 'item' in Google Earth and the POI will be in a forested area nowhere near a street, road or highway. Google Earth image is within a year, so it's not like the image was from 10 years ago and sprawl has occurred in the meantime.

I have encountered problems with some POI files for stores and restaurants located in large malls. It depends on where the file creator decided to locate the "entrance" - to the mall or to the facility itself.

However, what you describe sounds more like an error with the coordinates of the item. Using decimal coordinates, you could be off by several kilometers by entering an incorrect digit in the first or second decimal place. And then you could be half a world away by reversing the latitude/longitude coordinates.

As pointed out earlier, converting street addresses to coordinates can be a pain... but I have not encountered very many problems using files from the POI Factory.

I think I downloaded 3

I think I downloaded 3 files. The POIs are similar to this:

365 E 17th St.

Super Walmart Center #3000 Tulsa

Walmart 275

There is no rhyme or reason as to which POI is the actual location. Sometimes the address POI would be close & the 2nd example way off the mark. In the next town it could be reversed. A lot of times, the 3rd example would just be the main intersection of the locale.

Heck even when there is a shaded spot, labelled Walmart @ a mall, the POIs aren't close.

@revrnd

Thanks for the three examples.

I am assuming these are from the poi-factory POI file named
Walmart_United States & Canada.csv (628.9 KB)
which I just downloaded.

I looked for POIs in this file that would match your examples but was unable to find anything.

Can you be a bit more specific, please?

Yes

Some are pretty bad. I write down the specific poi and send in the correct latitude and longitude or change of address, whatever it needs to whom ever takes care of the file. Never had issues doing it this way. Its a small thing. smile

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nüvi®3580LMT,nüvi®2598LMT| We do not live in Igloo's, and do not all ride to work on snow mobiles.

I've already winnowed out

I've already winnowed out the duplicate/inaccurate POIs, so I can't. All I know is that the POIs were labelled 3 different ways. I checked my Download folder & I must've deleted the files after loading them into Base Camp.

Sorry.