Who's Best for Getting Coordinates by Address?
16 years
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Okay I'm a newbie with GPS and am experimenting creating POI files.
My first project was to create a Star (Yamaha) Motorcycle POI and was using Microsoft's Terra Server to get the coordinates. Its slow going but I mapped out my state and most the surrounding states.
The problem comes with validating the coordinates. Most look fine when you map them on the terra server. But when I put them into google or elsewhere, most seem a little to a lot off.
So I experimented using my home address with terra server, google and yahoo. All three gave slightly different coordinates. Yahoo wasn't too bad - only being one house down. Terra server was off by about 150 yards and was on the street next to mine. Google was a good 300 yards off and on the wrong side of a highway.
Obviously, these are consumer coordinates and will not be totally accurate. However, I do want to be able to "trust" the POI enough to actually navigate to destination I haven't been to before. Being a down the road in an unfamiliar area wont help all that much and could be potentially dangerous.
Which brings me to my question. What is the favored coordinate grabbing site? Is this just something we'll have to live with until consumer coordinates get better? Assuming that this is something that there isn't a good answer to, will I (we) just have to live with persons correcting the coordinates over time and actually traveling to the location?
Thanks,
Dave
P.S. Yes I did find the Yamaha POI on this site and thank you for those involved in the creation.
I like the free Google Earth
I like the free Google Earth program.
I created a POI file and I
I created a POI file and I used Google maps. I found the area on the map then switched to the satelite photos. Once I found the exact thing I wanted to locate, my house for instance, I centered it in the display and entered this code in the browser address bar:
javascript:void(prompt('',gApplication.getMap().getCenter()));
Then hit go. It gives the co-ordinates to 15 decimal points. At that point it is just cut and paste.
Sounds like years to create
I use geocoding service from yahoo. I don't know if it is accurate to withing so many feet, but I consider POI's created by users to be within a hopefully 300 feet or so. It should at least be on the same block as the GPS says it is. If someone wants to finance my trip, I would be glad to hop on the motorcycle and verify every location on any POI given here. But if the POI gets me close enought to see what I was looking for, then it is working great.
Rodney.. oditius.htc@gmail.com BMW Zumo 550 HTC Touch Pro - Garmin XT
I like Geocoder.ca ...
...and find it pretty accurate. It's good for both Canadian and U.S. locations. However, my favorite way is to actually visit the site, and make it 100% accurate, assuming I don't write it down incorrectly.
I disagree partially about 'If you're within a few hundred yards, that's good enough.' Maybe it's good enough for findng Wal-Mart, which is monstrous and visible a long ways off. But, looking for a little store front with some small sign, maybe, and driving up and back on congested roads is not fun. The value of GPS's is pinpoint accuracy, and not maybe, sorta, kinda right locations.
GC
Nuvi 350, GPS Map 76CX
Thanks All
Thanks to everyone for the replies. As I said above, I'm pretty new to all this and at least it seems like I'm getting up to speed.
geocoding
So far I have found by using Geocoding I get a hit most every time I put a address in.Not as lucky with others.
Charlie. Nuvi 265 WT and Nuvi 2597 LMT. MapFactor Navigator - Offline Maps & GPS.
Google earth
I have just got my Nuvi660. I uploaded to it my POI with the help of Google earth. Today, I tested it and it turned to be quite well. First, I tried to go to a place I already know and the result was within 50 meters from the destination. Then, I tried to go to a place I do not know, the result within 100 meters. I guess Googlearth is not reliable in terms of accuracy, but its ease of use for first timers like me is evident.
Found this site, while surfing around...
http://www.gorissen.info/Pierre/maps/googleMapLocationv3.php
Sweet!!
http://www.gorissen.info/Pierre/maps/googleMapLocationv3.php
WOW!....What a great site!!!
TOMTOM - LG LN740 - Magellan Roadmate 1430 - Garmin Nüvi 255W - Garmin 2455LMT
Not very accurate?
http://www.gorissen.info/Pierre/maps/googleMapLocationv3.php
I typed in where I work, 1440 S. Kilbourn Ave. Chicago, IL 60623 and it was a block off and on the wrong side of the street. I go to: http://www.gpsvisualizer.com/ and use the easy batch. (Yahoo) and entered the address. It gave me the coordinates and I pasted them into this site and it was correct. I don't trust googles mapping system.
Rodney.. oditius.htc@gmail.com BMW Zumo 550 HTC Touch Pro - Garmin XT
Use more than one
I found TerraServer to be the worst. Often entering addresses is off a bit in Google maps. Yahoo maps seems to be more accurate when using addresses. I use Google Earth to verify and get a visual with the satellite maps. It seems odd, but Google Maps and Google Earth use different maps and routing engines. The other issue is how addresses are listed. You see "1234 MyStreet S." and the map program doesn't understand that because it only knows about "1234 MyStreet E." Sometimes it will take you to a totally different locale.
Other tools to use are company websites. Often they will have location descriptions like "1/4 block from anystreet av." Thats helpful when using Google Earth because you can usually get a better feel for what buildings and such are located in a given area. Some places are easier to visually locate than others, like campgrounds. You can see the campsites and circle roads. Some end up being a bit of a wag no matter what you do. The only thing then is to mark it as a favorite if you ever actually go there and update the POI later.
Ultimately, don't give your paper maps and good sense. GPS is a great tool, but its not the only thing you should rely on.
Chuck - Nuvi 200, Nuvi 255W
Best geocoding site
My son created a Excel file with macros that will run both Google and Yahoo and give results for both and then give the average between them. It also provides precision results and any warnings about the results.
He has just joined the site and will be receiving his new Nuvi 650 from my wife and I for Christmas. I'll see if he would be interested in sharing the file with this forum.
As for accuracy, I find both are OK but in any case one must check the coordinates in a program like mapsource to be sure they are accurate.
Nuvi 350 - North Carolina - I'm not a native Southerner but I got here as fast as I could!
Who's Best for Getting Coordinates by Address?
I have found Mapsource to be extremely accurate. Zoom in as much as you want to get the accuracy you desire. Put the pointer on the exact spot then right click and select one of the names then click on waypoint. Give the poi a name and your done. Click on "file" "save as" and select .gpx in the bottom box to create the file. POI Loader will then pick it up and load into your gps.
Nuvi 2460LMT
Excel File
I would be interested in that
file. Hopefully your son will
let you post it.
Personally I like to put in coordinates
right into the google map website
search address bar. For example here
is a coordinate for MGM Studio Disney
that I was just looking at
28.3783 -81.5528 Make sure the negative
number goes second. I use this to check
for accuracy.
Google Maps will also fix GPS coordinates
for you. For example. I just completed a project
on wisconsin interstate rest areas. From the
DOT website of wisconsin here is the GPS
coordinates it gives for one particular rest
area found here: http://www.dot.wisconsin.gov/travel/restareas/ra9.htm
You will see the GPS coordinates given are as follows: N 43° 45.692' W -89° 58.441' I copy and paste without the N and W letters so it looks like
this: 43° 45.692' -89° 58.441' Then, plug this into google map search bar and viola it pops up with the following coordinates 43.761533, -89.974017
and you can see on the map it is accurate. I then use this for my POI file.
My son's Excel program
I'll see him on Christmas Day and will ask if he is interested in posting it. Obviously, it will come with disclaimers for accuracy as he is only automating the search in both Google and Yahoo.
He may also have tweaked it by the time I ask.
Nuvi 350 - North Carolina - I'm not a native Southerner but I got here as fast as I could!
Please do.
I'll see him on Christmas Day and will ask if he is interested in posting it. Obviously, it will come with disclaimers for accuracy as he is only automating the search in both Google and Yahoo.
He may also have tweaked it by the time I ask.
I would be interested in the excel files also.
Thanks
Same Here
I'm also interested in the excel file. This thread is turning real interesting to me. Love the different ideas people are sharing on how they get their coordinates.
Use More Than One
I have a basic understanding of how to "modify" Custom POI's so that they are accurate. Recently I noticed that one of my "built-in" locations for a restaurant was off by a couple of blocks, using my nuvi 650. My question is: Can I modify the built-in POI's or am I going to have to live with it? (By built-in I mean the ones that already were preloaded on my 650).
Thanks,
JeffSh
Who's Best for Getting Coordinates by Address
Mapsource By Garmin Then Google Earth Second
Auggie SP2720 , SP C330, Nuvi 650, Nuvi 785T,Dezl 770lmt America Moves By Truck
GeePeeEx Editor
The Editor seems to give the same geocoding as the gps visualizer. It also has map and satellite views and you can write your own poi files with this program. Even attach pictures if you wish. I entered my home address and the co-ordinates were dead on with my nuvi to within 4 decimal places. That is close enough for almost anything.
gpsvisualizer.com
I typed in where I work, 1440 S. Kilbourn Ave. Chicago, IL 60623 and it was a block off and on the wrong side of the street. I go to: http://www.gpsvisualizer.com/ and use the easy batch. (Yahoo) and entered the address. It gave me the coordinates and I pasted them into this site and it was correct. I don't trust googles mapping system.
Gpsvisualizer.com has a possible built-in error. When using gpsvisualizer with default yahoo settings, it will give the coordinates of the address if it finds the address. If it can't, it will give the coordinates of the street, city, zip, state, or country. When geocoding a single address, the 'result precision' window will tell which location the coordinates are for. But when doing a batch conversion, "you really don't know" ... there being the built-in error.
RT
"Internet: As Yogi Berra would say, "Don't believe 90% of what you read, and verify the other half."
Aleve 90
I think you will have to look at all of them, and make the decision of which one is the best for you. Your the one that will use it.
This is almost asking which is the best automobile, Ford or Chevrolet. How many answers would you get? Everyone has their favorite.
I put the same exact address in Terraserver, and Google Earth. They were exactly 1 mile apart when I got to the destination.
Garmin 660
RE: My Son's Excel Program
The Excel program/spreadsheet can be downloaded using the link below. It is very easy to use. Just enter your addresses, click the Geocode button, and it will geocode using both Google and Yahoo geocoding services. It also gives you an average latitude and longitude since Google and Yahoo generate slightly different results.
I plan on making many improvements to this once I have some free time.
http://members.cox.net/br1an/
Calibrating POIs
I have recorded 5 random POIs with Nuvi 350 and checked all exact points with Google Earth. Then, I calculated the differences in each POIs. I found out that if you get the coordinates from Google Earth and subtract 0.000150 from latitude and 0.000300 from longitude, your real location and corrected Google Earth locations are matching exactly. At least they were for the 5 points I experimented.
address coordinates
Okay I'm a newbie with GPS and am experimenting creating POI files.
My first project was to create a Star (Yamaha) Motorcycle POI and was using Microsoft's Terra Server to get the coordinates. Its slow going but I mapped out my state and most the surrounding states.
The problem comes with validating the coordinates. Most look fine when you map them on the terra server. But when I put them into google or elsewhere, most seem a little to a lot off.
So I experimented using my home address with terra server, google and yahoo. All three gave slightly different coordinates. Yahoo wasn't too bad - only being one house down. Terra server was off by about 150 yards and was on the street next to mine. Google was a good 300 yards off and on the wrong side of a highway.
Obviously, these are consumer coordinates and will not be totally accurate. However, I do want to be able to "trust" the POI enough to actually navigate to destination I haven't been to before. Being a down the road in an unfamiliar area wont help all that much and could be potentially dangerous.
Which brings me to my question. What is the favored coordinate grabbing site? Is this just something we'll have to live with until consumer coordinates get better? Assuming that this is something that there isn't a good answer to, will I (we) just have to live with persons correcting the coordinates over time and actually traveling to the location?
Thanks,
Dave
P.S. Yes I did find the Yamaha POI on this site and thank you for those involved in the creation.
Going by my personal experiences and talking to some so called experts, it seems that most address coordinates are anywhere from 100 to 300 feet off. A surveyor told me that addresses on mapping programs are figured in the following manner. On any given street the mapping people take known coordinates at two different points and figure everything in between mathematically. Where the problem comes in, is it is figured as every lot being the same size. I don't know if what I was told is right or wrong, but I know my address is probably 2 or 3 hundred feet off. Microsoft S&T tells me our block goes to 1972 when actually it goes to 1958. Maybe someone on the forum has more expertise with this type of thing.
I guess the bottom line is, if the GPS gets me within 300 feet of a POI and I can't find it from there I'm an idiot.
Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong.