Creating an accurate POI file can be tedious

In building the BofA file, would it be possible to put in some comment that indicates that it is an ATM only?

What I often want to do when on vacation is to find the nearest branch - not the nearest ATM. If there were a way to pull out of the file all of the ATM's only, then I would be left with branches.

I tried to put the word "Remote" in for ATM only, but didn't get them all.

If I get an actual list from BoA - I will be sure to correct any that are missing and I will be more diligent for the states to come.

Will start putting "Branch" or "Remote" in for the next state which will be RI.

I agree with you. Even with its limitations, especially with street addresses, Google Earth is the best way available to geocode. It beats having to go to every location.

My policy is to start small and make sure locations are as accurate as necessary. I feel this is better than offering many locations with doubtful accuracy.

dobs108 Nassau County NY

After numerous restarts on a file I found starting small and checking how it looks in a GPS is the best way. You also get to see what info is there or still needed as a "nice to have".

Metricman Quote "First, let me say that the most accurate way to create a POI file is to be there with a GPS and record the L/L of the location, then transfer the data to the file."

It's even more fun when locals have their name for a road (ie Danforth Rd), Google map, sat, aerial shows another (Route 30), web site gives another (Main St) and Google street view is shows County Rd 30 on the signs. Some places in my files are so remote there is no aerial, sat is useless and the map view is all you have and you may or not have street view. Or the mailing and delivery address is a PO Box and hours of web searching won't give you a physical address and you can't phone the place because the number isn't listed or is wrong. But then I guess you just hope that somebody who downloaded the file lives near the place and can send you the correct info.

I know how tedious it can be. Try finding a boat 20 feet long in Google Earth.

Another way is to use the GPS-Equalizer (name?) for filling in L/L blanks, but that has the same errors as Google and the rest.

I'll just keep plugging away at it. I hope that no other state is as concentrated as MA was.

I did find 2 50 ft long planes in the Atlantic, off of Pea Island NC.

This is just a thought, as I sit here putzing with the various Googles, EPE, and MapSource myself...

Out of all of the variables in getting to an accurate location with a Garmin, at least MapSource can show you the map that's on your unit, and the street numbers according to it.

Not that it won't have errors as well. I'm just throwing it out here.

Metricman wrote:

When I made the Williamsburg POI file, I tried a couple of ways. I used Google Earth and I also tried the U.S Geophysical Survey digital maps. Both were disappointing. Field checking the results showed that the accuracy was just not good enough for doors that were sometimes just a few feet apart. Not only that, but the doors are usually not visible in a satelitte photo or on a map. My Nuvi will give me 18 foot accuracy or better outdoors, which is more reliable than Google Earth, in my opinion.

I would beg to differ with a couple of Metricman's observations. First of all, Google Earth is extremely accurate with its latitude and longitude, all the way down to six decimal places. Jeez, how many more decimal places do you need before GE is "good enough" for you? Now, having said that, I also concede that the skill in getting good lat/long numbers often takes a fair amount of skill. Many of the sat pictures are extremely fuzzy, and therefore practically useless. While it would be nice for businesses to provide their customers the lat/long of all of their locations, that's not how it is yet. So it becomes the responsibility of the person wanting that information to track down the locations and put GE's crosshairs where they belong.

The second point in Metricman's post that I don't agree with is his comment about some doors being mere feet apart and therefore not distinguishable by GE. I would argue that that degree of accuracy is unnecessary. I've got news for you: if I'm in my car and my GPSr gets me to a door a few feet away from the door I really need, that's close enough. I'll find what I'm looking for.

I generally agree about his other points, especially about street and highway names being inconsistant. One of the problems that I have is that in rural areas, all maps show the street name as being the numeric route number, while the internals of the GPSr use the local street names, which are only known by the locals living in the immediate area.

Whether you are using Google Maps or Earth or the GPSr itself, addresses are not always accurate because the map does not have the coordinates of each address. I assume the coordinates of intersections are accurate and the position of an address is estimated by comparing it with the other addresses between two intersections.

This works when intersections are close together but fails when intersections are far apart. Many business websites have a mini Google Maps or Mapquest map to show where they are located, and these aren't always accurate.

I predict that Enhanced 911 systems will someday have the coordinates of every building in their area. When used with the real-time coordinates of emergency vehicles, computerized dispatching would be possible. The coordinates of addresses would be made available to businesses (for a fee) and Google Maps and Earth would then be able to obtain this info.

dobs108

Plunder,

There is some error involved when a "Flat" image of a curved surface is projected back onto a curved surface. Also, there is an error if the satellite is shooting at an angle other than absolute "0 Degrees" down. Go to any large city and note that the buildings are usually "Tilted". You can usually see one or more sides of the building in the image. I've seen this "tilt" on one story buildings. The further you go from directly overhead (0 degrees), then the greater the angle of tilt will be (plus - add in the curve of the earth to add to the tilt). and then you have to add in the altitude of the location, which adds to the error. These are "Commercial" images, not Military, and therfore not as accurate or as high a resolution.

Would you trust Google positioning to put a Cruise Missle into a 6 ft X 6 ft hole in the side of a 12,000 ft high mountain? I wouldn't! But we aren't doing that here. Just because Google Earth displays to 6 decimal places, doesn't mean that it is always that accurate.

Take your GPS to any landmark in your area - like the end of your driveway (please be outdoors and be sure the landmark is visible in Google E). Record the L/L from the GPS and then check it against Google E. My Garmin read (-)XX.72086, XX.36337 (claiming 18 ft accuracy) and Google E says -XX.72077, XX.720774. Entering the Garmin coordinates into Google E puts the indicator about 25 ft away. You can see some of the West walls of the houses in my neighborhood (but not much of the wall), so the satelitte was not directly overhead when the image was made. This observation throws the 6 decimal places accuracy right out the door.

Anybody else out there try this? How much error did you get?

If you go to:

http://www.poi-factory.com/node/21554

and if you read what I wrote, you will see that you have to "walk" in the restored area. You can't drive during the day and the POI is intended for those that have handheld GPS devices, and yes some doors to different buildings are mere feet apart. I made each location distinct so that users could see the proximity of each location when "zoomed in".

Not trying to start a big debate or argument, but check out the accuracy of Google E yourself before making any reply.

FYI, I did visit one University where they actually listed the L/L of some locations. I guess that the more GPS equipped IPOD's, etc. become popular - the more we will see the L/L being given.

Where I live, the 2 counties and the city have maps already in Digital form. These maps can supply Street Address, owner(s) name, history of owners, how much assesed for by county/city (tax assessment) and how much property has been sold for, for each sale.

They also can display a map of the parcels and you click on the parcel to get the information. Visit your local government Commissioner of Revenue "online" to see if they have a map. I'm curious as to how many localities have done this.

All they need is the money to do it, if they already haven't done it.

I have a feel for what Metricman is saying, and it's not as much accuracy as it is 'alignment' and completeness in some cases. Although in mapping all are the same I suppose, inaccurate.

For example, I have mapped my yard boundaries in GE and it's very accurate in linear measure and coordinate 'granularity'. However the coords don't exactly convert & match to my state's state plane GIS data, and we all know my GPS coords aren't going to match exactly either.. and neither my Magellan or Garmin do. I could use them pretty well for driving, but not so accurately walking.

And then the other data attached to the coords (like address number, road width & placement, etc) in the different data sources differs.

One of the reasons I suggested MapSource as an alternative is that I'm working on a poi 'test' file with a route attached. There is a difference in the 'roads' on Google Maps & Google Earth, and my Garmin map. Both in exact position as well as in existence. I found a great spot in GE to place my test pois and driving route only to find that the roads (not exactly public..Watkins Glen Motorway!) were not on the Garmin map set.

BTW, Maryland does the land ownership maps statewide & there is a LOT of various state GIS data & maps available.

I wouldnt go so far as staying such project is very difficult

I use geepeex and use the geocode function.
It gets me roughly to where I wanna be..then I just fine tune it using a hybrid map.

Granted, doing this on a block of buildings your not familiar with can be difficult...
But for something like drag strips that I added to a master file, it was pretty easy.
Generally its the long 1/4 strip.
Plop the location at the entrance and your done.

dood, dragstrips show up on Google Earth like they were airports!

dobs108