[Geocoding] General Nominatim questions

[Charles Randall]

To follow up on a question below slightly differently:
Is Nominatim data at the street level only? Or does the dataset include
house numbers as well? I'm trying to get a feel for how much data might
have house numbers vs. just street level data. Any information here would
be helpful - if metro areas have house number data generally, or other
details.



Thanks!
Charles

On Mon, Oct 15, 2012 at 3:08 PM, Charles Randall <crandall747 at gmail.com>wrote:

> Thanks for the responses Sarah. I didn't understand address details fully
> before, but on second read it makes sense. Thanks for all the info!
>
> Charles.
>
>
>
> On Mon, Oct 15, 2012 at 2:01 PM, Sarah Hoffmann <lonvia at denofr.de> wrote:
>
>> Hi,
>>
>> On Mon, Oct 15, 2012 at 11:33:17AM -0700, Charles Randall wrote:
>> > Hey all -
>> > I've got a couple of random Nominatim questions for the group:
>> >
>> > a. Nominatim accuracy: A number of times, when I put in a specific house
>> > address for Nominatim, I get back a lat long, which doesnt vary with
>> street
>> > numbers.
>> > - I assume this is because of the data files used.
>>
>> This happens, when the house numbers are not in the database, then the
>> coordinate of the street is returned.
>>
>> > - Do people do anything to make these more accurate?
>>
>> You can always survey house numbers and add them to the OSM database.
>>
>> > b. Address details option in URL:
>> > I'm curious, if I set the nominatim query string to have the option
>> > "addressdetails=1", what exactly is coming back in the data I see
>> returned?
>> > I feel like the different sets of place id's returned is the lat long
>> > address details of the other street options that are listed on the main
>> > screen when you do a query.
>>
>> I'm not sure I understand that question. What you get back with
>> addressdatails
>> is a list of the parts of the address together with their designation
>> (street,
>> city, county, country, etc.)
>>
>> > c. Are there particular xml files for US address data that some people
>> find
>> > are more accurate than others?
>>
>> Not sure how that relates to Nominatim. It's primary source is data from
>> OSM,
>> there are no other xml files. You'll find different excerpts in the
>> internet
>> but they all come from one source - OpenStreetMap.
>>
>> For the US, it can also be made to use Tiger house number data on top of
>> the
>> OSM data, which will most help with your problem from question 1. I can't
>> really comment on the accuracy of this additional TIGER data. Maybe others
>> know better.
>>
>> Sarah
>>
>
>
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