More precisely, the WGS84 Datum is not used everywhere.

Here is some background:

• The WGS84 Coordinate Reference System uses an ITRF datum, locked with the Earth’s rotation.

• The tectonic plates we’re living on, are moving, up to 70 to 80 mm/year for the Australian plate, 20 to 25 mm/year for the Eurasian one.

• The tectonic plates have internal distortions (we do ignore them here)

If you have a very accurate GNSS receiver which shows you WGS84 coordinates, and place it on a survey mark, because this mark moves, you won’t get the same coordinates year after year. If you surveyed a mark in Australia 13 years ago, today’s coordinates are 1 meter off. So, accurate WGS84 coordinates are not accurate at all if you don’t know the epoch, just as a time value is unuseful if you don’t know the time zone. Working with dynamic coordinates would be a nightmare for the surveyors. To make their life easier they use a datum associated with their continental plate, locked at a point in time. And for a few decades now, many countries have chosen an ITRF datum and “locked” it at a specific date. With such a datum, the coordinates of survey marks remain the same over the years.

• USA is using NAD83

• Australian is using GDA94 (ITRS epoch 1994.0)

• Europe is using ETRS89 (ITRS epoch 1993.0)

• France (in europe) is using RGF93, a more accurate ETRS89 realization. We consider that RGF93 = ETRS89.

You could object this is not an OSM problem : we use gpx trace, aerial imagery, opendata sets, all with WGS84 coordinates!

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The last wall maps I generated of Ashgabat and Turkmenistan took a different turn, due to the heavy data requirements involved in a road atlas of the whole country. I was forced to learn Osmosis and the rudiments of Inkscape to edit SVG files first in order to reduce the volume of data and second to take the Maperitive-generated map and tweak it more easily. The lessons learned are now posted on the OSM wiki here. Comments on this tutorial are welcome.

Working with SVG images has its pros and cons, but on balance I think the map quality is better with this approach. That said, one can only wish that Inkscape and Osmosis were a bit more intuitive!

The Import

Yesterday I performed an import of NaPTAN bus stop data for the Aberdeen area. The motivations behind this import were:

1. To greatly increase the coverage of bus stop data in the area.
2. To get some experience importing data (hence the very specific and simple scope of this import).
3. To establish a method of importing NaPTAN data since the original import was abandoned (and all of this very useful data has been sitting unused).

Results

Increased Stop Coverage

The import changsets can be found by looking at user naptan_import_aberdeen.

In total there were 63 regions of the Aberdeen area imported as separate changesets. Across those a total of 1357 bus stops were imported - of which 875 (64%) were new and 482 (36%) were conflated with existing stops.

The Aberdeen region (the city centre) had the most stops with 154 total. While the Countesswells and Footdee regions tied for the least with just 1 stop each.

Experience Gained

I think the most valuable experience I’ve gained from this import was in consulting the community and following the import guidelines. It’s quite daunting when you first see the guidelines and was honestly a little off-putting for me personally because I’ve been fatigued by aspects of the OSM community in the past. Thankfully, the UK community are quick to respond on the mailing lists and very helpful and constructive.

If I hadn’t consulted the mailing lists then I wouldn’t have known how useful and important some of the NaPTAN data fields are. Originally I was of the mindset that only the naptan:AtcoCode was necessary to import since it establishes a link between the OSM data and the NaPTAN data. However, after actually performing the import I can already say that the other fields helped me to distinguish between stops in close proximity with the same name.

Method Established

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When two ways (two railways, or two parts of a motorroad) are close together they start overlapping at some point when going to smaller scale, like railway in this picture:

… See full entry

After seeing how lacking the map of my hometown is, today I started to add shops and amenities one by one on the ground using OSMAnd and uploading them instantly or when at home, then fixing the incorrect ones using JOSM.

I believe I can add quite a lot if I do this everyday as the city is pretty small but some hand would surely be welcome.

Soliciting FB folk to get together to get more data into OSM for OCM use (https://www.facebook.com/groups/anchorbike/?multi_permalinks=390920768438984&notif_id=1563078024658217)

(US) State Parks: Searching for Common Ground

DRAFT FOR COMMENTS: Please do not treat as a formal proposal!

Introduction

For as long as I’ve been a participant on the OpenStreetMap project, the subject of what to tag a ‘State Park’ in the US has been fraught with controversy. (In some areas, there are equally controversial facilities named ‘county park’, ‘town park’ and so on with similar structure but administered by a still lower level of government.)

In this post, I try to find a common thread that can hopefully be used as a common foundation for all parties discussing the issue. Some of the specific examples given will be New York-centric. I apologize in advance for the fact. I am a native New Yorker, and I use examples with which I am familiar. I strongly prefer to map in places where I have boots on the ground - by which I usually mean literal boots on the literal ground. I have trodden the soil of all the places that I use as examples.

Proposal summary

State Parks should, as a ‘lowest common denominator’ be tagged with boundary=protected_area protect_class=21 (This combination would be the minimum necessary for rendering. Ordinarily, a state park would also have some combination such as protection_object=recreation protection_title="State Park"

Background

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Recently the OSM group over at Telegram crafted a form for OSM editors with the goal of knowing our community a little better. This form questions who you are, how you work and if you have any feedback to any OSM services. Please share this so we can reach every type of mapper and get the whole picture! :)

The form is available here

The data will be published here 11th August, 2019, with indefinitive graphs and sneak peaks on Telegram every week till then. Username and date of submissions will not be connected with individual answers in the final results.

You can join the OSM Telegram group to stay up to date!

Syver

Intoduction

SVG texture support was an important part of for this Google Summer of Code project. Apart from the reasons mentioned in the application document, on why adding Scalable Vector Graphics support would be benefitial, its true importance lays on this fact: Most Wikimedia CC0 available images are SVG files. That would also be the reason that led in “swapping” priorities between the 3d and 4th task listed in the application; SVGs had to be supported if users were to make use of textures provided in traffic sign catalogues like this one.
By the end of it, this task ended up leaving some extra time in our hands, presenting a good opportunity to implement another useful functionality: Make external fonts configurable and able to be registered in the application. (Note: “external” refers to fonts not supported by default in the user’s OS). The need for a functionality like this (mostly) derived from the fact that texts on traffic signs use fonts not so widespread (e.g. Interstate) but it can also come in handy in many other cases as well.
The changes described bellow can be found under the July 12 2019 commits of this feature’s branch.
So, with that out of the way, let’s see how everything got blended into the project:

SVG textures support

The concept of implementing svg textures support was pretty straightforward: a really good support for png images already exists, that of course works with all target outputs of OSM2World; so converting svgs to pngs to make further use it would be the best course of action. As of the latest updates described in a previous diary entry, image layers in a texture are now of the ImageTextureData type. That of course makes ImageTextureData.java the appropriate class to implement such a mechanism.
A couple of changes took place in that class:

… See full entry

Before

This was originally posted by myself on 5 June 2019; it is another Diary as part of mapping Nottingham’s Creative Quarter, this time musing on Points of Interest (PoI) as part of mapping for OSM.

One of many reasons for entering PoIs in the map is that Nominatum (the search facility within OSM) uses PoI to find results including (amongst other items) postcodes. I discovered this when I could not find the Covid-19 Jabbing-centre in the OSM map, yet confirmed afterwards that I had entered the correct postcode.

A conversation with the lady at AST Auto Centre

I could not be certain either from my original visit nor from our Bing imagery whether some central buildings were occupied by the Ashley St. Auto Centre (below) or by a business on the opposite side of the block on Handel Street, so phoned the number on the business card that the lady at AST had given me on 17 May. This was 4 June so I did not expect her to remember me but she did, and mentioned the little leaflet that I had given her.

I quickly sorted the original reason for the call (AST occupies those buildings), but as soon as I mentioned OSM she immediately responded about the number of enquiries that the business gets via Google maps (I had never mentioned Google). I brightly informed her that the updated mapping should be available within the next hour.

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Indian Linux Users Group, Chennai [ ILUGC ] is spreading awareness on Free/Open Source Software (F/OSS) in Chennai since January 1998.

We usually meet on the second Saturday of every month, and for the month of July we shall meet on Saturday, July 13, 2019 at 1500 IST.

Venue: Classroom No 1, Aerospace Engineering, Near Gajendra Circle, IIT Madras. Link for the Map: http://bit.ly/iitm-aero Event Details: Event 1:

Topic: Debian 10 “Buster” Release Party

Description: Debian 10 Buster was released few days back. Let us celebrate with Cake and a discussion about it. Duration: 20 minutes Event 2:

Topic: Mini-Mapathon for OpenStreetMap.org

Description: OpenStreetMap.org is a colloborative created maps system, which is provided open map data for all. Let us learn and contribute to OSM in this mini mapathon.

Duration: 2 hours

Speaker: Barani

About Speaker: This is Barani tharan, an enthusiastic open source Contributor. I have started OSM contribution during OSM Mapathon organized by FSFTN. I have mapped all roads, places etc in my Hometown. Its been more than 2 years I started contribution, Still it continuing. When I move to new place or City I note maximum places and roads and map in OSM. During OSM Mapathon I got 3rd place which gives more encouragement to Mapping.

Let’s map for people… Happy Mapping :-)

Here are video introduction in Tamil for OSM. Watch these videos.

http://www.kaniyam.com/video-on-openstreetmaps-org-in-tamil/

http://www.kaniyam.com/video-on-openstreetmap-org-in-tamil-part-2/ Requirements:

This is full handson session. All participants should bring their laptops.

Create an account in https://www.openstreetmap.org/
Bring with a Laptop, Charger
Bring your own internet connection like mobile hotspot or wifi hotspot (We dont have internet at IITM)

After Talks:

QA & general discussions

Entry free. All are welcome.

Before

This was originally posted by myself on 6 May 2019. It is an attempt to document the then-recent spam/abuse problem within these Diaries in a scientific manner. The idea was to allow the wider community to get a fuller grasp on the issues and help answer some fundamental questions. After all, nobody knows everything. Here is my attempt to state some of those questions and to try to answer some of them:–

Some Questions:

1. Is this Spam, Abuse, or a mixture of the two?
   (the motivation behind those two are completely different)
2. Are they bot-posts, human-posts, or a mixture of the two?
   (prevention mechanisms for those two differ)
3. What are the best methods to prevent this from continuing?
   (best practices have been evolved across the last 20 years, but OSM is not your typical forum/blog)

Some Answers:

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 As a Barangay Deparment that holds the census that also records the map of the CELO   (certificate of lot occupancy) which is challenging us from the census in a row / small house when it comes to   CELO to be specifie in each home's house who has availed CELO (certificate) to stand up for   their establishment.  https://www.openstreetmap.org/#map=17/14.53746/121.11067 



    * Beneficiaries of 8,000 ISF households or estimated population of Arenda
    * using motor / bicycle / walking using additional street-level imagery with Mapillary
    * plan to increase house numbers
    * supplementing important data (e.g. health centers, place of worship, pharmacy, 
       miscellaneous) without CELO because it is important to the community
    * it has a population of 70,000 hectares
    * future plans for DRR, PWD use, etc.  

Example this CELO Tagging for every house hold addr:neighbourhood: addr:quarter: addr:street: addr:town: addr:village: building: place: ref:PH:CELO: osm.org/edit#map=20/14.53817/121.10791 https://lh3.googleusercontent.com/-6X5mCt1mIZg/XSPp1e7UxTI/AAAAAAACxY8/WTK5VmUdYEoDC6CI9QH7SGkGEzjMU9UiQCK8BGAs/s0/2019-07-08.png osm.org/changeset/71582475#map=17/14.53670/121.10912&layers=N

and it is your best look at where it is clearer and better now in the area of ​​the barangay santa ana taytay rizal.

https://lh3.googleusercontent.com/-GdRLwYHye3g/XSPqB7J9RKI/AAAAAAACxZA/Dx6fcPXDezUUtSmivdMKWNuofN8VglvWwCK8BGAs/s0/2019-07-08.png

thank you

The tagging of the Adirondack and Catskill Parks as boundary=national_park has been fraught with controversy. I’m more or less responsible for the tagging decision, and I’ve decided to make a diary entry explaining it, so that I don’t have to keep repeating the explanation.

These two entities are not ‘State Parks’ - unlike other parks such as Allegany State Park or Harriman State Park. In fact, they are unique entities in New York, and quite possibly the US and even the world.

Unlike most parks, which are created by statute, or even by executive proclamation, the Adirondack and Catskill Parks were created by a constitutional convention in New York, and are explicitly enshrined in article XIV of the state constitution, which begins:

The lands of the state, now owned or hereafter acquired, constituting the Forest Preserve as now fixed by law, shall be forever kept as wild forest lands. They shall not be leased, sold or exchanged, or be taken by any corporation, public or private, nor shall the timber thereon be sold, removed or destroyed.

This is the strongest protection enjoyed by any park or nature reserve of which I am aware. While all the others that I know about could be destroyed by a legislature’s passing a bill, any significant change to the Adirondack and Catskill Parks requires a constitutional amendment. There have been several such over the years, but none has come close to repeal. The most significant ones were the authorizations to construct the Olympic sports complex at Lake Placid, to build Interstate 87 through the Adirondacks, and to permit New York City to construct reservoirs and draw its water supply from the Catskills.

… See full entry

This is pretty cool, learned a lot of ways and the tools here to be used to expand our locations and areas through an open source format that everyone is available to enter and volunteer.

This method should be used more often to have a constant update in our maps!

Last weekend, a couple of OSM volunteers and drone enthusiasts visited Lupang Arenda in Taytay, Rizal. The visit was part of the ongoing collaboration with Barangay Santa Ana in Taytay to use OpenStreetMap as one of their tools for managing community initiatives. The origins of this collaboration has an interesting back story but I won’t talk about it on this post. ;)

The main goal of the visit is to capture images using drones to create an updated aerial imagery of the community to identify individual building/houses. For a densely populated community like Lupang Arenda, it is difficult to get this level of detail using satellite imagery.

The crew. Photo by Erwin Olario.

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According to Wikipedia there are four main tennis surfaces types:

• Clay courts
• Grass courts
• Hard courts
• Carpet courts

But when looking at the “sport=tennis’ tag the English and German Wiki pages are note very accurate about the tennis court surface types. The English page does not recommend any “surface” values but refers to the Wiki page (which is ok), but the German page talks about “clay”, “asphalt”, “grass” and “sand”.

But when looking at the”surface” key, only “clay”, “decoturf” and “carpet” are connected with tennis.

“DecoTurf” is a special tennis hardcourt product manufactured by an US company. I think we should avoid using “surface=decoturf”.

When checking taginfo of “sport=tennis” you can see more than 96% of them are combined with “leisure=pitch” but only less than 9% have a “surface” tag. Most of them are “clay”, followed by “paved”, “asphalt”, “concrete” and “sand”. (Next to) none of them are tagged with surface “grass” or “carpet” (or even “decoturf” (good!))!

I am not sure yet, how to tag hard courts (I tend to “hardcourt”), but we should only use the following values for “surface”:

• clay
• grass
• hardcourt
• carpet

Direction of a way representing waterway=dam or waterway=weir is important, because you want to know which side is lower, and which one is higher - it usually the one on the side of landuse=reservoir, but sometimes reservoirs could go in sequences, sometimes with very small separating parts:

Test

Hello. I am here at Grab PH’s office for the OSMPH x GrabPH Mapathon to help map areas located in Taytay, Cainta, Angono, and Binangonan, Rizal.