Convert address to latitude and longitude

Several input options...

http://www.gpsvisualizer.com/geocoding.html

This one is a free one for doing batches of addresses.

http://www.batchgeocode.com/

Does 24 different countries

http://www.travelgis.com/geocode/

I use this one, I was going to mention it but didn't want the guy to get beat down with bandwidth issues. I like it because it has a batch mode.

Good point. I also like it because it retrieves results from several different sites like those listed below. "One stop" shopping as they say.

I also use the Steve Morse site. Most times you'll get lat/long from all 5 sources, but sometimes only 2 or 3 or 4. You can use a spreadsheet to average the 2 or 3 or 4 or 5 results you get for a single address. That works for doing one address at a time. Haven't tried using that site in batch mode.

If you average 2 or more sources of coordinates you're going to be guaranteed of an error in the averaged coordinates (unless all coordinates are identical). If you have one 'nuts-on' and one off, you have a 50% chance of being in error. If you average them, you have a 100% chance of being in error.

Sould we really expect a coordinate provider to make sure their data is correct when they know we are going to average it with data from some provider who doesn't give a darn?

RT

RT wrote: "Should we really expect a coordinate provider to make sure their data is correct when they know we are going to average it with data from some provider who doesn't give a darn?"

My view is that the coordinate providers are going to do whatever the coordinate providers are going to do. I really don't think they know or care that there are folks like me who might average results from several sources. And I have no way of knowing which source is consistently accurate. So I go for some kind of a "consensus" reading, Guaranteed error? Yes, you're certainly right about that: only one of the readings is closest to the true coordinates. But which one? I have no way of knowing that.

If I knew more about statistics, I'd have built my spreadsheet to toss out any results that deviate too far from the others. But I don't, so I just eyeball the results and toss out any that vary significantly from the others.

This is an oldish thread-but got referenced in a new thread - so better late than never

The actual 'Coordinate Providers' such as Yahoo! or Google do care about the accuracy of their results and return a "Precision Level" statement to indicate this.

From what I can tell, the majority of the Online Batch Geocoding services do not (or cannot) return that precision-level. So if they get an answer (even if it's Country-level!), that's what you get.

If you start averaging results (which could be to different levels of precision), the outcome is going to be meaningless, isn't it?

IMHO anything below "Street-level" is useless for navigation purposes...really "Address-level" is what you need.

I'm rather new to creating POIs, so can't comment knowledgeably. I got the idea for averaging coordinates from what I understand determines the accuracy of a GPSr 's coordinates: the more satellites it receives, the more accurate the coordinates. As I understand it, the GPSr averages out the results from the satellites it receives, and thereby smoothes out error.

Since writing my original post, I've tested my "averaging" method against Google Earth. And I humbly say that the results were rather good. It helps that I first standardize addresses to USPS specs. And when I get the 3 or 4 or 5 results from Steve Morse's "1 Step" Web page, I toss out any coordinates that are outliers or that show an incorrect address.

Also since writing my original post, I've adopted the methodology of using geocoded coordinates to get me close to the target, and then using Google Earth to try to refine the results. That works well if the target is, say, a big-box Wal-Mart in the suburbs. It doesn't work so well on crowded city streets.

Still looking for perfection. But still not sure what providers will get me there.

Here is another site:

http://terraserver-usa.com/default.aspx

Google Earth also allows you to convert Street address to Log. and Lat.

Averaging the accurate one with not accurate ones makes the accurate one not accurate anymore. So I just take the original un-modified data of one source, assuming it is most accurate. The issue is which one to chose...

The medium method is to select the longitude that half of the others are larger and other half are smaller. Do the same to select the medium Latitude.

If lucky, the medium longitude and Latitude are from the same source, then the answer is clear. When one source has the medium longitude and the other has the medium latitude, Pick the one has the less delta different from the medium longitude/Latitude.
(Say... Source A has the medium longitude and 0.003 differ from the medium Latitude. Source B has the medium Latitude and 0.002 differ from the medium longitude. Then the Source B more likely to be the accurate one.)

newport wrote:

Google Earth also allows you to convert Street address to Log. and Lat.

Although it's not practical to use a lot of the time, Google Earth is the only way to go if you want exact coordinates. If you know what you're looking for, just move the yellow push pin to the exact position (such as 20' up a driveway or parking lot entrance), note the latitude and longitude, then use

http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html

to convert them to decimal values.
It's uncanny how accurate this method is to a GPSr.

When I started making POI files using Google Earth, I set the options to display decimal degrees by default.

Tools>Options>3D View tab>Show Lat/Long>Decimal Degrees

I agree Google Earth is a great means of finding locations, but you don't need to do the conversion stage. In Google Earth, select:

"Tools | Options | 3D view | Show Lat/Long => Decimal Degrees"

to show them in the 'correct' (ie Garmin standard) format.

Better still, save them out of Google Earth as a .kml file, to avoid any possibility of typing errors.

EDIT: Gary, you either type faster than me, or don't have a disruptive 10 year old in the house

Phil - no disruptive 10 year old in the house... just a wife.

Acme Mapper (http://mapper.acme.com/) gets the coordinates and marks it right in Google Maps for you. Options let you set your preferred coordinate format and units of measure (English/Metric).

Yet another geocoder you could try is the USC WebGIS Geocoder (https://webgis.usc.edu) - there are several API's as well as facilities for processing uploaded databases.

Not having a 10 yr old around the house.

Addresses of retailers in large malls are notoriously bad. Has anyone a fix for this issue from a lat/lon standpoint?
If the streets within the mall are not recognized you have to manually find the store...... Some malls are huge.
Chuck

A Security guard at an outdoor Simon mall informed me that I was not allowed to use my gps to obtain coordinates and make a POI file of the stores in the mall. My solution was to quit frequenting all Simon Malls.

There is no law that I am aware of that would prevent you from getting GPS addresses of a store that caters to the public. Now if you were trying to get coordinates of a secure facility, then the action of the security officer could be warranted. We have a few Simon Malls in our area and no security guard has ever approached me when I was there with my GPS. Perhaps you should contact Simon Malls to determine if there policy is to not allow anyone to obtain the coordinates of stores in their malls. Provide them with the positives of having their stores mapped to specific grid coordinates.

I usually note it is a mall location in either the name or description and then give coordinates to either the center of the mall or the main entrance to the parking lot if it can be determined.

In my opinion, a file for automobile routing should always use the entrance to the parking lot. If you use the center of the mall the gps will take you to the closest point on mapped roads, even if that is a road behind the mall with no entrance to the mall's parking lot.

A POI file of the mall itself (for pedestrian travel), using off-road mode, is what I was trying to build, because as Chuck pointed out, some malls are huge and can be difficult to navigate.

As I stated - I identify the store as a mall location in either the name or description field. Should a mall be located with many entrances to the parking areas, what are YOU going to use for a 'main entrance?' Your entrance on the West side may not be readily accessible to some on coming from the south, east, or north but having a coordinate at the center of the large, enclosed mall lets the unit route according to the direction of approach.

Personally, if my GPS routed me to a large mall, I would use a little common sense about finding a place to park rather than expecting it to lead me to the door closest to the store unless it was an anchor and identifiable through satellite imagery.

I did the UNO Chicago Grill POI and a lot of their locations are in or near malls. The standalone locations as an outbuilding are fairly recognizable, the interior locations are not. The standalones are pretty uniformly marked at an entrance off the main frontage or at a main route through a parking lot. It's the ones inside the mall or building complex that are the problem.

These are good sites to use especially when reporting Red Light cameras or other POI's to miss POI. It makes her life a lot easier if she gets coordinates along with street address/locations.

If you use the format of all commercial POI files, then you would use the street address of the Mall for the location. If you look at the web site for most stores located in a mall, or even the telephone book, you'll see that they mostly all use the same street address as the mall. This will get you close to one of the entrances.

As bentbiker correctly stated, you should always place the coordinates at the entrance to the parking lot, and NOT the center of the mall.

If you place the coordinates at the center of the mall the GPS may guide you to a side of the mall with no entrances. Because the GPS doesn't know where the actual mall entrances are located. All the GPS sees are streets. To the GPS the mall is just a big empty square (or whatever shape the mall may be). Look up your local mall on your GPS and see for yourself.

I have firsthand knowledge of this issue because I made the same mistake when I first started creating custom POI files. I thought I would be slick and place the coordinates right in front of a store at a strip mall. Well, when I tried to drive to the location lets just say I didn't get the results I wanted.

So always place the coordinates at an actual entrance to the mall.

Again, which entrance is the "main" entrance when there are four or more major roads intersecting at the location, each with a separated entrance road?

What about the mall with entrances off two access roads from intersecting Interstates?

If when searching for the store you see Gadzooks - MegaMall, Boondocks AR would you have a clue the store was located someplace on the mall property and would then take the physical destination as getting you someplace in the mall or would you blindly follow the directions to the trash dumpsters?

There are times when the "actual entrance" cannot be determined and any coordinate is going to be off. My preference is get me to the mall at the nearest entrance in the direction I'm coming from rather than drive around the mile and a half loop to park on the wrong side anyway.

.

Let me give one example of a problem. Your destination is a mall directly south of you. It is flanked on the south by Main St, and it stretches from 1st to 2nd Streets on the east and west sides. However, to the north of the mall is a giant walled community with one main entrance that leads right to the center of the mall, but there is no access. You will therefore be dumped at the end of the street with no idea that you have to retrace your steps and any turn you make before getting back to the main entrance will take you to a dead end at the wall.

A mall that is bordered on one side by a small stream could pose a similar problem. You can't always drive around the periphery of a mall.

A POI located at any one entrance to the mall will assure that you get into the parking lot of the mall -- I could care less if there is an entrance that is 1 mile closer, I just don't want to be dumped somewhere that has no access to the mall.

If the mall is huge and none of the internal streets are designated you must physically find the store you want. Your gps will not cross country.
What does UPS or FEDex do to make their deliveries or pick ups? It must be a learning thing.
If the gps gets you to the mall you will have to remember where the store is the next time you come.
Chuck

How did you ever find a store or address before you had a GPS? GPS is a tool. It points you in the right direction. It can't take you by the nose and drag you.

Try finding the AMC theaters at Arrowhead Mall in Glendale, AZ (spur of the moment). We drove around for 15 minutes (using the location of the Garmin favorite, not even close).
Even using the website map (preplanned trip) the location is only approximate, very approximate. Follow the signs if you can find them.
We now know where to go and it is easy.
Chuck

You could have found it in one minute. Just call the theater and ask where they are located in the mall.

Your kidding right, your saying you expect a Gps to take you to the right door of a mall?

You would have to think, some people would be thinned out mankind if it wasn't for kindness of others.
Egad what would you have done before you owned a GPS?

Agree with BobDee, if it gets me to the parking lot then I think I can take on the responsibility to find the store I want. I think to many people expect way to muck from their gps. I have the same thought about cell phones what did everyone do before they came along. waited till they got home to talk. Just my old age showing I guess. (yes I have a cell phone).

You can always create two POIs - one for the door, and one for the entrance to the car park. You could even set your final destination as the door and add the other one in as a 'via point'. Best of both worlds!

um - in my case, it was an Ice Skating rink and a Railway line

Thanks for the tip

My point is:
using the gps to get to a particular store in a large mall would be the equivalent of:
inserting an address in the gps and following it to "somewhere" on the square block where the address is located.
On the gpsr:
Favorites get you to the basic mall address.
Should POIs be able to get you closer to that particular store? Maybe not......
Chuck