SK53 has commented on the following diary entries

Post When Comment
"Duck Lanes" on OSM? 6 months ago

Please dont map animal tracks in general & certainly not as paths. First in some places there are many many animal tracks (mountainsides with sheep come to mind). Secondly, animal tracks tend to change depending on circumstances. Thirdly, mapping lots of traces which are not necessarily usable by people will just make OSM data hard to use.

Thoughts on the import of address nodes in JOSM using MassGIS L3 Parcel data to aid in adding addresses to buildings in MA 6 months ago

Virtually all the MassGIS imports have suffered from major and significant problems. Firstly the import of streets did not join ways at boundaries. As the import was on city/town boundaries rather than county elsewhere making MA routable was extremely tedious.

Current parcel boundaries do not seem to be massively accurate. For instance this playground in Yarmouth Port is not contained within the two forks of Playground Lane and Old Church Road. It's a while since I last visited, but Google StreetView & Bing aerial imagery confirm that the MassGIS boundary shown on OSM is inaccurate. A little to the East beyond the end of Damaris Drive there are multiple overlapping polygons for wetland & conservation areas: very difficult to work out what they are doing. I've tidied some of these up using aerial imagery/memory in the vicinity of Bass Hole/Grey's Beach, but my impression is many of these polygons are more general than we expect with OSM.

Another area with problems in the past was the Hyannis Transportation Centre. Most buildings had been imported, but as they were imported some considerable time after the roads; the new road network was not in place. I added this (and fortunately Lars Ahlzen has done more) when trying to put the P&B bus route in.

The significant problem with these imports is that everything looks complete, but in reality it requires considerable revision, checking against current status, and judicious removal of useless data (see the large number of tags on the playground above). Very large numbers of highway=residential are nothing of the sort, but most likely driveways to properties (certainly along the Kings Highway in Barnstable, Yarmouth Port, & Dennis places I'm reasonably familiar with).

A side effect of this is if one looks at POI density in the Upper Cape, it is woeful. Only 28 restaurants mapped in the Barnstable admin division, which includes multiple popular holiday resorts including Hyannisport. (Only 1 in Rockport, 4 in Gloucester, 1 in Plymouth, 8 in Harwich, and NONE on Nantucket, etc). It doesn't help that GNIS nodes are often inaccurately placed (such as Friends Meeting House on Nantucket which is several streets away from its actual location), and close to its likely location MASS GIS buildings sit on top of MASS GIS roads.

All in all these are reasons why I would be extremely cautious about further mass imports of data for Massachusetts. I cant be certain, but my basic feeling is that at least POIs would be better represented in the absence of these imports. Adding housenumbers would give further weight to the appearance of a complete and detailed map: but in practice in places I know, OSM is much less useful than it could be.

Alternative processes would be to put your data set up somewhere so that local users could use this as the basis for mapping (e.g., as a tiled layer or similar), or simply make it available in such a way that it can be integrated with OSM data at the data consumption stage, so that applications can use it (in practice geolocated address nodes may be all that is needed)

Vikumberg, Fünfenberg, Tabor nad Botačem, Draški Tabor, Tabor di Draga, Castello di Moccó, Lorencan, Sv. Lorenc 6 months ago

Great bit of detective work!

Melbourne tram stop project - first post 7 months ago

You might like to take note of Mapillary. Open Data from VicRoads is being progressively loaded onto Mapillary: this may really help add details without committing to visit every tram stop.

I cant find an example with trams because many of these sequences have not yet been fully processed by Mapillary and dont yet show up as a blue line on the map.

#1009 - Nepal Earthquake, 2015, Gorkha 7 months ago

Some of the aerial imagery, particularly the grey scale MapBox imagery is quite difficult to interpret and in particular I have noticed that ridge lines and valley bottoms are often initially difficult to pick out.

The two ways to check are a) use the OpenCycleMap layer which shows contours and b) zoom out until you have Landsat satellite data. With the latter the overall topography becomes much clearer. (I may put a bit on the wiki in the next day or so now that you've raised it).

In areas where this is particularly difficult to interpret I actually crudely map ridge lines (natural=ridge) as well as waterways. This not only provides data, but helps to keep the context of the imagery clearer. I discuss this a little on my blog about mapping Lesotho.

How many amenities are open for a given time? 7 months ago

Nice thoughts.

I think the graphs are confusing because of the variable axes. In practice the vast majority of entries are parsable. I'd suggest making the % axis from 0-100, and perhaps adding another line showing total parsable entries using the right axis.

What I dont get a feel of is how many elements might have opening hours tags on them vs those that dont: for instance most shop=* might be expected to be valid elements for opening_hours.

Another thing which one might be able to pick up, in Germany at least, is the local Ruhetag, just from which day typically has different opening hours in an area.

Potlatch and contour lines 7 months ago

I imagine you used OpenCycleMap as a background layer. This no longer appears in the default layers. I dont know if this was deliberate, or accidental. I imagine you can still create this as a layer for Potlatch2.

The town with the most toilets on the world! 7 months ago

I doubt if the things tagged as toilets in Tandale are private toilets, some are probably Open Defecation Areas, others might be communal toilets. Most of the 50k+ inhabitants will not have access to any kind of private toilet facility. An overpass query counts around 550 POIs, so roughly 100 people:1 toilet.

Tandale has been mapped by local people with guidance from experienced OpenStreetMappers.under a Development Seed programme.

I suggest reading some of the following:

And a youtube video of Mark Iliffe and Gary Gale made in Tandale.

Hamlets in US cities 9 months ago

@lxbarth This sounds a) a great typology and b) good sense; but it raises one of my long standing tagging concerns. Just what is the best way to tag trailer/mobile home parks over-and-above just using landuse=residential?

Hamlets in US cities 9 months ago

@lxbarth This sounds a) a great typology and b) good sense; but it raises one of my long standing tagging concerns. Just what is the best way to tag trailer/mobile home parks over-and-above just using landuse=residential?

Hamlets in US cities 9 months ago

Nice post, this has been a personal bugbear for ages. I'd love to see a concerted effort to fix this.

The obvious alternatives are place=suburb & place=neighbourhood (possibly place=locality, but like hamlet I expect that in rural areas). A third was is just to place a landuse polygon of the appropriate type and add the name tag

Many of these are industrial/commericial areas with a low population (hence why they got the hamlet tag), but in some cases it's just that the naming of areas in the city is at a fine degree of granularity.

It's not because you have accurate data that you have to upload all of them in OSM 9 months ago

And we have really accurate position of the pins on the golf course, which will of course get moved every few days to keep green wear constant.

Who are the Missing Mappers? Part II 10 months ago

Fundamentally I agree with this, but I also think that practical surveying experience greatly assists in interpreting images even in unfamiliar places.

I know that my initial mapping in Port-de-Prince was very much informed by how much I had learnt from adding stuff remotely and then discovering that in reality things were rather different. There is always a danger of over-interpreting remote imagery, and exposure to this issue by actual survey experience really helps.

In the short time allotted for a Missing Maps session practical surveying is obviously impossible, but I think there is scope for using things like Mapillary sequences etc., to place remote mapping in a context together with on-the-ground surveys.

Years ago nickw and I spent half a day presenting OSM at a MapAction training weekend. I remember being surprised by how many of those present had edited OSM in their local area. Perhaps this was besides being GIS pros, many wanted a feel for how data was created. After all, they use it in earnest during humanitarian crises.

Casas de sucos 11 months ago

I dont think it's quite right, but will do for a start, providing you add some other tag which will enable you to find juice bars. In my case I've added cuisine=milkshake as such a start.

Casas de sucos 11 months ago

There is a (small ?) chain called Shakeaway in the UK and elsewhere selling Milkshakes. These have been tagged in several different ways: amenity=cafe, amenity=fastfood, shop=yes, shop=beverages. So we could do with an answer too. There are close analogies to ice cream places (not exactly food, can consume in or take away).

Learn-a-tag: leisure=fitness_station 11 months ago

Certainly noticed several in Parque Centenario in Buenos Aires. There is also a very little used tag covering several of these leisure=outdoor_gym. In Switzerland and nearby there are specific trails with fitness stations located along the trail. There has been an ongoing project to map them for several years: ParscoursVita.

Learn-a-tag: highway=escape 11 months ago

Agree this is a nice idea, useful info, and simpler to execute than the old project of the week.

Mapillary | Ahmedabad - Rajkot Highway | NH47 11 months ago

Great sequence, nice clear pictures. I've used them to add a couple of petrol (gas) stations to the W of Chotila, but couldnt locate the power line on aerial imagery.

Danish rowing clubs complete 11 months ago

Interesting that the common tag is leisure=sports_centre.

I think this was originally meant for a centre offering a wide range of sports activities, rather than the building housing one or two sports, but I know the second meaning is very common. Perhaps we need another tag for places which host multiple sports (e.g., swimming pool, fitness centre, hall for racquet games, basketball or 5-a-side, plus changing facilities and outdoor pitches).

Second question, I recently mapped the Buenos Aires Rowing Club (sic) at Tigre. They have another large place which is clearly more a social than sporting facility. Does this apply to any of your Rowing Clubs, as it most certainly applies to some clubs in the UK.

Website for asking to improve just one area in OpenStreetMap (or paying for improvement) 12 months ago

If I found people mapping from notes for a bounty in the local area I'd be pretty cross.

In general we have little evidence that remote mappers really improve places which are well mapped, by ground survey and the data available to them (mainly aerial imagery) is often out-of-date or inadequate to resolve issues. I have certainly noticed people have made decisions about how something is likely to be when local folk have already determined that a place requires a ground survey.

I have from time to time added extra detail because remote mappers have started fiddling with data which is reported through tools such as KeepRight. I have done this vaguely under duress so as to stop well-meaning, but usually pointless, tweaking of the map data.

If it was to happen on a regular on-going scale, I suspect it would deter me from continuing to contribute.