topic Re: Help with geocoding in State & Local Government Questions

Help with geocoding

ELTerrell — Thu, 21 May 2015 16:05:23 GMT

Hi,

I just added a spreadsheet of 7 different points. I used GPS Visualizer: Free geocoders: Convert addresses to GPS coordinates to geocode my addresses (city halls). 4 of the 7 when placed on the map, were mapped correctly. The other three were waaaay north of the county I'm mapping. I used Geographic Coordinate System: Name: GCS_WGS_1984 to add my xy data. Does anyone have any suggestions as to how/why this happened and how I can fix it? Thanks so much.

Re: Help with geocoding

StevenGraf1 — Thu, 21 May 2015 16:12:55 GMT

Did you personally check those 3 that were incorrect? I have a feeling the Address to XY tool you used didn't return the correct coordinates.

Steven

Re: Help with geocoding

JoeBorgione — Thu, 21 May 2015 16:34:14 GMT

I'm with Steve, but would add: Is it possible that the addresses that are mis-matched actually valid in the space they fall? For example, are there more than one 1234 Main St addresses in your vicinity?

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 17:20:29 GMT

Not sure if those streets are locating on an appropriate place elsewhere, it's pretty far away from my county. When you geocode using that website, it will show you a map of where the point lies. Looking at it for all 3 addresses, there are in the correct location. I've also used another geocoding website to double check. I wasn't sure if it was GIS or the geocode that was messing up but that seems to make it seem like it's GIS, not the geocode site.

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 17:30:55 GMT

actually, looking at the streets baselayer, the streets it located on isn't even close. I'm in NC and it puts the 3 addresses in WV. If it helps, the addresses are:

2	39.783730	-80.839782	Huntersville	101 Huntersville-Concord Rd, Huntersville, NC 28078
4	39.783730	-80.849961	Davidson	216 S. Main St, Davidson, NC 28036
6	39.783730	-80.718555	Matthews	232 Matthews Station St, Matthews, NC 28105

Re: Help with geocoding

StevenGraf1 — Thu, 21 May 2015 17:38:27 GMT

Here's what I got when I put those in to the geocoder you listed:

latitude,longitude,name,desc,color,source,precision

39.78373,-100.445882,"101 Huntersville-Concord Rd, Huntersville, NC 28078",US,,MapQuest Open,country

35.497836,-80.849496,"216 S Main St, Davidson, NC 28036","216 South Main Street, Davidson, Mecklenburg County, NC, US",,MapQuest Open,address

35.117336,-80.72053,"232 Matthews Station St, Matthews, NC 28105","Matthews Station Street, Matthews, Mecklenburg County, NC, US",,MapQuest Open,street

Re: Help with geocoding

StevenGraf1 — Thu, 21 May 2015 17:40:03 GMT

Looks like it can't find 232 on the last address so it's defaulting to the street name. They most likely don't have a sufficient address range in their data that is valid for 232.

Steven

Re: Help with geocoding

JoeBorgione — Thu, 21 May 2015 17:43:57 GMT

Ever check here for NC GIS data? Maybe 'rolling your own' locator is a better way to go....

Just a thought.

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 18:24:50 GMT

Ok, those coordinate have finally worked except for the Huntersville coordinates. That one is in Kansas.

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 18:25:23 GMT

Haven't checked out this site yet. How do you roll your own?

Re: Help with geocoding

StevenGraf1 — Thu, 21 May 2015 18:30:07 GMT

Ya, it looks like it can't find any part of the address so it's throwing it in the middle of the US.

Re: Help with geocoding

StevenGraf1 — Thu, 21 May 2015 18:32:30 GMT

You will need some type of reference data such as a road centerline file with address ranges. Once you have a source data file you can follow these instructions.

If all these points are in the same county or counties, it might be your best bet to see if your local county or city GIS department has those layers. That would be your most accurate data. They like to strip information out when they send data to a data repository.

ArcGIS Help 10.1

Steven.

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 18:34:15 GMT

I played with the source (bing maps v. mapquest open) feature on that site. Using different sources produces pretty different x coordinates. Using one gives -100, another gives -80. Even with the -80 (similar x coordinate to the other addresses), it still puts it up on WV. Very odd.

Re: Help with geocoding

JoeBorgione — Thu, 21 May 2015 19:42:47 GMT

Check this link out: Geocoding – Some learning resources

https://community.esri.com/docs/DOC-6206#comment-14223

It's an awesome resource!

Re: Help with geocoding

ELTerrell — Thu, 21 May 2015 19:59:11 GMT

I ended up using this site Free Online Non-Parsed Postal Address Geocoding (texas a&m) and was able to finally get gis to recognize the coordinates. Funny, even when using the same coordinates for 'go to xy' feature it came up with a different location than uploading that address in a spreadsheet.