[talk-au] JOSM Scanaerial plugin on NSW LPI layers

Sat Jan 23 02:43:11 UTC 2016

On 23/01/16 12:26, Nev Wedding wrote:
> I have followed this process for Kooyong State Conservation Area which 
> has gone well after opening the kms file and have simplified and added 
> all the tags,
> …but on trying to upload the final boundary I get this ominous message
> “
> You are about to upload data from the layer 'Kooyong.kml'.
>
> Sending data from this layer is *strongly discouraged*. If you continue,
> it may require you subsequently have to revert your changes, or force 
> other contributors to.
>
> Are you sure you want to continue?
> “
>
> I assume the warning is to dissuade mappers from careless import of 
> large uncorrected datasets.?
>

Yes.

> Sooo…, am I ok to continue or is there another reason?  ..I am on-hold 
> here until I see a reply
>
> Nev
>
>
However you may want to upload one, provide a link to it and then see 
what others think.

Cheers
Ross

>> On 22 Jan 2016, at 11:36 PM, Andrew Davidson <u887 at internode.on.net 
>> <mailto:u887 at internode.on.net>> wrote:
>>
>> You can extract the geometries from the database directly, you don't 
>> have to scan them. I tried this on three park areas to see how much 
>> work was involved. The recipe I followed was:
>>
>> 1. Use the query tool to find out how many objects have the name that 
>> you are looking for. You do this with:
>>
>> http://maps.six.nsw.gov.au/arcgis/rest/services/public/NSW_Administrative_Boundaries/MapServer/6/query
>>
>> with the return format set to html. Names must be in upper case and 
>> you need to see what object ids are returned. For example if you 
>> search for Yanununbeyan with:
>>
>> http://maps.six.nsw.gov.au/arcgis/rest/services/public/NSW_Administrative_Boundaries/MapServer/6/query?text=YANUNUNBEYAN&geometry=&geometryType=esriGeometryEnvelope&inSR=&spatialRel=esriSpatialRelIntersects&relationParam=&objectIds=&where=&time=&returnCountOnly=false&returnIdsOnly=false&returnGeometry=true&maxAllowableOffset=&outSR=&outFields=&f=html
>>
>> You get three different ids (198,208,1131) because there is a 
>> Yanununbeyan State Conservation Area, Yanununbeyan Nature Reserve, 
>> and Yanununbeyan National Park. All of which need to be tagged 
>> differently. Follow the object links to find out what type of area 
>> they are.
>>
>> 2. Having found the object id you need you get the geometry by using 
>> the query tool and setting the object id, setting the output spatial 
>> reference to 4326 (WGS84), and changing the output format to JSON.
>>
>> 3. Save the resulting page, say output.json
>>
>> 4. Use ogr2ogr from GDAL to convert the output into something JOSM 
>> can read:
>>
>> ogr2ogr -f "KML" output.json output.kml
>>
>> 5. If you have the opendata plugin installed you can open output.kml 
>> in JOSM.
>>
>> 6. Use the simplify way option in JOSM as there are far too many 
>> points in the resulting kml. I personally thought that the default 3m 
>> looks OK.
>>
>> 7. Tag the ways with an appropriate source:geometry and add a note to 
>> the effect that the way has been simplified using a max error 
>> criterion set to whatever you used.
>>
>> 8. Now comes the difficult and time consuming bit. You have to cut up 
>> and conflate the new boundaries with the existing data as you merge 
>> each new way from the layer you opened the kml in to the layer the 
>> osm data is in. This is the step where you could really make a mess.
>>
>> I found while doing the few test cases that I had to:
>>
>> - Make sure that common boundaries use only one way (which means that 
>> the more parks, state forests, admin areas, etc that share ways the 
>> more time consuming it gets)
>>
>> - Make judgement calls about if you should use the new boundary or 
>> keep the existing way where the boundary is something physical on the 
>> ground like a river bank or coastline. This is why I tagged the new 
>> ways with source:geometry so other mappers can see where they came from.
>>
>> - If there are already ways in place, using the replace geometry 
>> function of the utils2 plugin to try and preserve history.
>>
>> The cases I tried as a test were:
>>
>> South East Forest National Park:
>> https://www.openstreetmap.org/relation/5853354
>>
>> Murramarang National Park:
>> https://www.openstreetmap.org/relation/5858067
>>
>> Clyde River National Park:
>> https://www.openstreetmap.org/relation/5857616
>>
>> The South East Forest case was a multi-hour mapping marathon as the 
>> park has a lot of separate sections and shares many boundaries with 
>> neighbouring state forests and parks. The other two were much simpler 
>> but Murramarang need more time than Clyde River as it has more 
>> sections and shares a lot of common ways with the coast and various 
>> rivers.
>>
>> As to the import question it seems to me that there is a tacit 
>> agreement that tracing the boundaries one at a time is acceptable 
>> (not sure what the rest of OSM would think about this). Given that 
>> the biggest problem with an import would be conflating the data with 
>> the existing, provided that we're carefully hand-crafting each park I 
>> think we're OK. Does anyone have a differing opinion?
>>
>>
>> On Tue, 19 Jan 2016 13:44:12 +1000
>> Nev Wedding <nwastra at gmail.com> wrote:
>>
>>> Should the JOSM Scanaerial plugin be able to scan the LPI NSW
>>> Administrative Boundaries NPWS Reserve WMS layer and others. I would
>>> like to zoom in to a section and use the plugin as an initial pass
>>> instead of manually mouse clicking around the long and winding
>>> boundary and then refine the result before tagging and uploading.
>>>
>>> https://wiki.openstreetmap.org/wiki/JOSM/Plugins/Scanaerial
>>> I am using a mac OS X and there are no instructions for that install
>>> so I may not have it set up correctly yet, so first up before
>>> proceeding further, I would like to know if it will help anyway.
>>>
>>> I am unfamiliar with tracing shapes other than tediously wandering
>>> around the boundaries one click at a time.
>>>
>>> I played around with Gimp and Inkscape but found that to be quite a
>>> task too and wasn’t sure if I could use the output in Josm in anyway.
>>>
>>> How do you manage such tasks? Are their special mouse tools available?
>>>
>>> Is what I am trying to do essentially considered to be part of an
>>> import and/or the current LPI layers unsuitable for the tracing
>>> process.
>>>
>>> Some links to where to find more info on this topic would be
>>> appreciated. _______________________________________________
>>> Talk-au mailing list
>>> Talk-au at openstreetmap.org
>>> https://lists.openstreetmap.org/listinfo/talk-au
>>
>>
>> -- 
>> Andrew Davidson <u887 at internode.on.net>
>
>
>
> _______________________________________________
> Talk-au mailing list
> Talk-au at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-au

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-au/attachments/20160123/a5678609/attachment.html>