Accuracy of Lat/Long data from POI editors

 

I searched this forum, but couldn't find an answer to:

a) I tried the online tool called http://www.poieditor.com/ that takes pointers from Google maps and creates/exports a CSV file with POI coordinates. But, it seems to truncate the numbers such that many coordinates in my town show-up as the same location.

b) I also see a cool tool listed on this web site that is an advanced POI editor with many extra data "fields"....Is there a source for the official "what's inside" a Garmin database?

c) Do I understand it corrrectly that my Garmin has a canned database, but that it only gets updated annually? Lots of places are NOT in their database unless I manually add them as POIs.

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New to the world of leisure-time GPS; will likely start a custom POI file for Rochester NY area since I can't seem to find one....

a. Try POI Edit and see if

a. Try POI Edit and see if you get different results (www.poiedit.com)

b. No. The database is not publicly known or available.

c. Yes. That's correct.

Check out

drhitch wrote:

I searched this forum, but couldn't find an answer to:

a) I tried the online tool called http://www.poieditor.com/ that takes pointers from Google maps and creates/exports a CSV file with POI coordinates. But, it seems to truncate the numbers such that many coordinates in my town show-up as the same location.

b) I also see a cool tool listed on this web site that is an advanced POI editor with many extra data "fields"....Is there a source for the official "what's inside" a Garmin database?

c) Do I understand it corrrectly that my Garmin has a canned database, but that it only gets updated annually? Lots of places are NOT in their database unless I manually add them as POIs.

http://GeePeeEx.googlepages.com Phil Hornby's program does an excellent job for $10 USD. Not related to Phil, just a happy user. smile

--
Computers are useless. They can only give you answers. - Pablo Picasso (Bob - Garmin c530, eTrex Vista HCx)

GeePeeEx

[quote=Summermug
http://GeePeeEx.googlepages.com Phil Hornby's program does an excellent job for $10 USD. Not related to Phil, just a happy user. smile

Don't see a $10 for the program but web says $17.99.
http://geepeeex.googlepages.com/downloadlinks

--
nuvi 2460LMT

http://www.takitwithme.com/

I have been using...

http://www.takitwithme.com/

for converting Google Maps that can be either uploaded directly to Garmin devices (into Favorites) or can generate GPX files which can be loaded into many different devices (goes into Custom POIs for a Garmin).

PT

--
Garmin nüvi 200 (my first GPS), 780, & 3700 Series. And a Mac user.

You're right.

mariner wrote:

[quote=Summermug
http://GeePeeEx.googlepages.com Phil Hornby's program does an excellent job for $10 USD. Not related to Phil, just a happy user. smile
Don't see a $10 for the program but web says $17.99.
http://geepeeex.googlepages.com/downloadlinks

Look like he has rasied the price since I purchased it. He has recently added some features.

Still think it's worth the money.

--
Computers are useless. They can only give you answers. - Pablo Picasso (Bob - Garmin c530, eTrex Vista HCx)

Like GeePeeEx Editor, too

Summermug wrote:

http://GeePeeEx.googlepages.com Phil Hornby's program does an excellent job for $10 USD. Not related to Phil, just a happy user. smile

Yeah, I second that. I tried a few things and found myself jumping from site to site and program to program to get what I wanted to do. GeePeeEx Editor did just about everything I wanted to do. Well worth the price.

And as far as geocoding goes, I understand that not all addresses geocode down to an individual address. Some will only get you street level accuracy and others will only get you to the city. This is really a function of geocoding, not so much the individual program. GeePeeEx Editor shows when an address results in a address-level, street or city level. When batch geocoding, you can tell it to stop on anything less accurate than address level accuracy. At least you would know that your address isn't working and could try something different or use map or satellite view to zero in better on the location you want.

Please Help!!! How to Geocode exact address

Hello, I am a newbee using a Magellan Maestro 4250. After reading up on Geocoding, I decided to try it myself but not having much luck with accuarcy.

I imported a csv file with (street address, city , state and zipcode), into Geocoder. It gave me back some coordinates.

I saved these back to the csv file. Then I opened it in the Magellan POI editor ..... dowloaded it to the GPS Unit.

However, on most of my entries it was usually accurate up-to the street NAME but never to the EXACT address. (none of my POI entries even showed a Street number in the GPS Unit)

1. IS there a good Geocoder that can do batch entries Exactly down to the street address (street number and street name)
2. Do the coordinates need to contain certain number of digits to be accurate down to the street level.
3. Is there a way to validate in the Magellan POI software if coordinates in that I have pulled are in fact for the exact address.....prior to uploading them to the GPS unit.

Any help would be greatly appriciated!!

Correct

Not every single place of business will be in the POI database, that is correct. I would guess maybe 20%-30% of places may be in. It is about the same for every GPS brand I have seen. However, it is still a pretty good database. Plus, with new businesses opening every year, it would be hard to keep it constantly updated, I would think.

Unfortunately, even some home businesses even get put in the database.

Search the web

vinniekhosla wrote:

Hello, I am a newbee using a Magellan Maestro 4250. After reading up on Geocoding, I decided to try it myself but not having much luck with accuarcy.

I imported a csv file with (street address, city , state and zipcode), into Geocoder. It gave me back some coordinates.

I saved these back to the csv file. Then I opened it in the Magellan POI editor ..... dowloaded it to the GPS Unit.

However, on most of my entries it was usually accurate up-to the street NAME but never to the EXACT address. (none of my POI entries even showed a Street number in the GPS Unit)

1. IS there a good Geocoder that can do batch entries Exactly down to the street address (street number and street name)
2. Do the coordinates need to contain certain number of digits to be accurate down to the street level.
3. Is there a way to validate in the Magellan POI software if coordinates in that I have pulled are in fact for the exact address.....prior to uploading them to the GPS unit.

Any help would be greatly appriciated!!

There is an abundant ammout of information on this subject on the web. http://www.bcc.cuny.edu/MathematicsComputerScience/ate/gps.h... explains some basics. I do not know if you can get the accuracy you are seeking but keep on trying.

I am not sure what the conversion is for the MGRS but I do know these are the milspec accuracies.
Military Grid Reference System:
1234 = 1000m accuracy
123456 = 100m accuracy
12345678= 10m accuracy
1234567890= 1m accuracy

Keep in mind your device may have limitations as to how many digits it will calculate.

Hope this helps and please keep us informed of your progress.

--
<><><><><>Trackin'- Garmin nuvi 660, Lowrance globalnav 212 and way too much Pro Audio equipment to list :-)<><><><><>

some follow questions

Thanks for the information regarding accuracy but this leads to a couple more questions
Let me see if I got this correct....All GPS system waypoints are based on coordinates and the Geocoder simply tells you the coordinates for a given address... and by importing these coordinates into a POI editor (ie Magellan POI Editor) it simply places those coordinates on the map. And next time you choose that waypoint the GPS will direct you to it.
Assuming that a single address will have a unique set of coordinates, then why will 2 coordinates not always point to the same address.

**ex: I used Geocoder.us to locate the coordinates for the address 10807 Jones Road, Houston, TX 77065 as being (29.929557, -95.584959). ..
----one thing I noticed: when I copied the coordinates into the POI Editor it rounded them off to Postnet 29.92956 -95.58496 10807 Jones Road, Houston, 77065

Then I uploaded it to my Magellan Maestro 4250 by using the Magellan POI Editor.

HOWEVER, when I selected the Postnet POI from the GPS Unit, the GPS displayed:

POSTNET, JONES Rd
HOUSTON, Texas

Why did the 10807 (the street number disappear) Keep in mind Jones road is almost 10 miles wrong. How can I be sure, that the GPS is not guiding me to 1087 Jones Road instead of 10807 Jones road.

And on some of the waypoints it completely changed the street name itself

Is there a way to validate that the address is the same as the one I entered.
.
**Also, does the Garmin POI editor go to 6 decimal places for the coordinates and display the exact address.

** Is there a better POI editor for Magellan that drills down to the exact street address.

thanks for helping me understand.

GPS Visualizer

Different web site close outcome.
29.929452,-95.585094,"10807 Jones Road, Houston, TX 77065"

--
Garmin 38 - Magellan Gold - Garmin Yellow eTrex - Nuvi 260 - Nuvi 2460LMT - Google Nexus 7 - Toyota Entune NAV

Sounds like you need a POI verifier.

GeePeeEx.com ($18 USD) does this very well. I use GeePeeEx. It has the capability to see your coordinates on a map and allows for you to move the waypoint then update the file with the new position. I begin using the geocode function then verify it on the map/satelite view. Very friendly program. Phil has done an excellent job with this program which is well worth the price if you plan on making any .gpx files. I like the phone dialing fuction as well. He is on this site frequently as "Hornbyp".

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<><><><><>Trackin'- Garmin nuvi 660, Lowrance globalnav 212 and way too much Pro Audio equipment to list :-)<><><><><>

GeePeeEx has great tools for GeoCoding

GeoCoding is just not that exact of a science. Not all address searches return an actual address-level accuracy. Some will only get you to the street. Others, only to the town itself.

What I like about GeePeeEx Editor is that it shows you what level of accuracy it has detected and you can see your location immediately in Map or Satellite view and adjust your coordinate cross-hair if necessary. If you are batch GeoCoding, you can set it to stop when it encounters an accuracy below a certain level or just highlight everything that returned less than an "address-level" accuracy. You can then call up the map or sat view to see what you actually got.