[Talk-es] [Imports] Spanish cadastre

[Carlos Dávila]

El 22/03/12 20:38, Paul Norman escribió:
>> From: Carlos Dávila [mailto:cdavilam en orangecorreo.es]
>> Sent: Thursday, March 22, 2012 5:28 AM
>> To: imports en openstreetmap.org
>> Subject: [Imports] Spanish cadastre
>>
>> This mail is to announce the intention of the Spanish OSM community to
>> import data from Spanish Cadastre and get feedback from you.
>> The idea of this import arises with the publication of the license and
>> access criteria to massive download of data from Spanish Cadastre [1] on
>> march 2011, which states: "Public use of cadastrial data is permitted,
>> including commercial use, if such data have been previously transformed
>> in any way...". Original data is supplied as shapefiles with different
>> coordinate reference systems. Reprojecting those shapefiles to EPSG:4326
>> and converting to *.osm format is enough transformation to allow
>> mentioned public use, according with the reference Spanish "Law of
>> intellectual property" [2], as established in its article 21, which also
>> says that copyrights of the transformed product belongs to the
>> transformer, in this case the (Spanish) OSM community.
>> Data from Spanish Cadastre is known to have a high accuracy and include
>> a lot of information of interest for OSM project, such as buildings
>> (shape, use, height, number of floors, etc.), rural and urban parcels
>> land use, most of streets and roads of the country, power stations,
>> tracks and paths, trees... Many of this information is currently in OSM,
>> mainly ways and roads, but a great part is still missing, specially in
>> low populated areas where a ground survey is less likely to be made.
>> This import has been largely discussed on Spanish mailing list, with a
>> general consensus on the usefulness of the import and a "we must do it"
>> agreement.
>> Specific software (cat2osm) is being developed [3] to import data, which
>> source code is available at Github [4]. It is currently being tested by
>> some members of the community to get a stable status. Some images of the
>> preliminary results can be seen at [5]. Transformed data is thought to
>> be always manually checked in JOSM by osmers knowing the area and only
>> after that uploaded. The way original data is translated into osm format
>> by cat2osm tool is documented in [6] and has been established with the
>> participation of several members of the community.
>>      
> What is your proposed tagging of these objects?
>
> Cadastre generally have a lot of detailed information, not all of which is
> suitable for importing into OSM. Which datasets do you intend to import and
> which do you intend to leave out?
>
>    
>> Specific accounts have been created for the import, one for each Spanish
>> province [7]. There's a member of the Spanish community responsible of
>> each province import.
>>      
> What software do you plan to use to conflate with existing OSM data?
> How do you intend to upload the data?
> Approximately how large will the changesets be?
>
>    
>> Looking forward for your comments
>> Carlos Dávila
>>      
> I suggest breaking your import proposal into sub-proposals for each type of
> data set. E.g. have a different proposal for roads than for buildings.
>
>
>
>    
cat2osm can process data of a given municipality as a whole or in 
separate steps, processing different kind of data. That result in 
separate *.osm files, containing buildings, highway=*, parcels, 
subparcels, etc. Also urban and rural areas are in separate input 
shapefiles. What I want to show you is that importer (remember it's not 
planned as an automated import) can control what to import and the size 
of the dataset to upload. I have uploaded some sample data to [1]. For a 
given municipality, zip contains raw data provided by cat2osm for 
highway=*, current data in OSM database and merged data for the urban 
area processed with JOSM. IMHO these data could be uploaded to OSM 
(using JOSM) without any risk to face those problems have been mentioned 
in this thread.

[1] http://mapas.alternativaslibres.es/Navalvillar.zip