I believe Nominatim relies on the US TIGER data for interpolating addresses. As such, here in New Zealand, if you query an address that isn't in the database it only returns a road section, e.g. https://nominatim.openstreetmap.org/search.php?q=207+Bealey+Avenue%2C+Christchurch&polygon_geojson=1. I'm experimenting with setting up a server and would really like this functionality (NZ' address data is not bad, but far from perfect). Is there any way of getting Nominatim to use the OSM data for interpolation? Alternatively, the TIGER Edge datasets look fairly straightforward and I could probably replicate them for New Zealand using address data from Land Information New Zealand. Has anybody tried this, or can anyone see any reason why it would or wouldn't work? Many thanks David asked 28 Apr '20, 11:23 David_EA |
US TIGER data for streets are only interpolations, the data doesn't contain positions of house numbers directly. You're right that Nominatim has separate logic to import the format and search. At search time for US addresses both OSM and US TIGER data are queried but since US TIGER data isn't rendered on a map it can be difficult to interpret the results sometimes. OSM tagging schema has https://wiki.openstreetmap.org/wiki/Addresses#Using_interpolation which is used throughout the world in some degree. Here's an example in NZ https://www.openstreetmap.org/way/266743982 (https://overpass-turbo.eu/s/To1) So tagging those in OSM should work just fine. answered 28 Apr '20, 14:19 mtmail I suspect the issue is that licensing for an import of the NZ address database, so adding addresses or address interpolations from it into OSM may not be possible. But if one were setting up their own Nominatim server then there is no problem having it query both OSM data and data from some other source. Since Nominatim has been setup to be able to use TIGER data but not NZ Land Information data, I think the question was would it work to convert the NZ data to the TIGER format. I know almost nothing about Nominatim, but that sounds like a reasonable way to go to me.
(28 Apr '20, 15:09)
n76
Nominatim keeps the TIGER data in separate database tables so avoid mixing. Have a look at http://nominatim.org/release-docs/latest/data-sources/US-Tiger/ how the data gets converted into .sql files for import so might want to generate similar .sql files. Throughout the Nominatim code base there's the variable CONST_Use_US_Tiger_Data (true, false) that determines when the data should be used. I'm sure there's another check for country_code=us which you'd need to change. https://lists.openstreetmap.org/pipermail/geocoding/ is good for discussing such projects.
(28 Apr '20, 16:13)
mtmail
Thanks for all the feedback. I think making a pseudo-Tiger file might be the way for me to progress as the OSM interpolation tag would need to be set up in thousands of places as we have a high (but not perfect) set of address data from LINZ (which is Creative Commons). Thanks again
(29 Apr '20, 09:18)
David_EA
https://wiki.openstreetmap.org/wiki/LINZ/Address_Import and the linked https://lists.openstreetmap.org/pipermail/imports/2017-June/thread.html#5014 has some detail about the licensing.
(29 Apr '20, 21:05)
mtmail
|