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Lighthouse Map

geodienst.github.io

134 pointsyread55 comments

Would love to know why Norway has so many lighthouses / "blinking beacons". Wikipedia lists many [0], but not as many as shown.

[0] https://en.wikipedia.org/wiki/List_of_lighthouses_in_Norway

It's because Norway made a conscious decision to maintain its lighthouses.

It's done to preserve the cultural legacy as the majority of lighthouses are obsolete.

Most lighthouses are cultural and historical icons, and they often faithfully reproduce the best technology of an era. Moreover, even if obsolete, most are wonderful architectural objects.

I can only applaud Norway's decision to preserve its cultural legacy. Shame others aren't as proactive.

The lighthouse in my town on Lake Michigan is preserved.

They had to cut a floor out of the building to restore it to historical condition when the Coast Guard moved out. Cracks me up.

(it had been in use as the base commander's residence)

That's good, at least sense prevailed and it's preserved.

It seems to include a lot of sector lights. Here is the nautical chart: https://norgeskart.no/#!?project=norgeskart&layers=1008

-That it does, I zoomed in on my local area (I can see five sector lights just from my office window on the northwestern coast of Norway - they're all over the place!) - all are present in the map.

I love this map; would be even better if one could set opacity for the lights so that it is simpler to see the coastline details, though.

Isn't a sector light a type of lighthouse?

Maybe they just have provided more detailed data? Then again, Norway has a very rugged coast which is used a lot.

I was going to suggest it might have something to do with all of the fiddly bits that were a favorite of Slartibartfast.

First light I checked, and have verified in real life, is missing. Patos Island light on the Canadian border in the San Juan island group. Cute, but inaccurate.

https://keepersofthepatoslight.org/about-patos-island

Then add it on open street maps, that's where this data is from.

The site is missing lighthouses all up and down the eastern US seaboard, but perhaps they'll take a few pull requests.

https://en.wikipedia.org/wiki/Harbour_Town_Light

https://en.wikipedia.org/wiki/Cape_St._George_Light

https://en.wikipedia.org/wiki/St._Simons_Island_Light

https://en.wikipedia.org/wiki/Tybee_Island_Light

https://en.wikipedia.org/wiki/Ponce_de_Leon_Inlet_Light

https://en.wikipedia.org/wiki/List_of_lighthouses_in_Florida

Data is from OpenStreetMap, so just add it there (which incidentally benefits all data consumers instead of just one single map). Note though, that Wikipedia is not a compatible source for OSM data; the licenses are incompatible.

It is an European project, it is to be expected

Thank you for confirming. I was a bit aghast at how few light houses the US eastern seaboard had, to the point I doubted the accuracy.

Same for Wangerooge, Neuer Leuchtturm.

Granted, there's a blinking thing a few dozen miles of in the North Sea instead.

Similarly, I looked for the one on Enoshima and it wasn't there.

Same, the Makapu‘u lighthouse on Oahu, Hawaii, seems to be missing.

Most of the mapped flashing dots in NW WA & SW BC don't match actual lights, nor do most of the charted physical lights have a flashing dot.

Seems to be quite Europe focussed, but then again 'Dienst" is Dutch for "Service". It's a project of the university of Groningen [0]

[0] https://www.rug.nl/society-business/centre-for-information-t...

The README [1] says it is using data from OpenStreetMap, fetched with the Overpass API.

[1]: https://github.com/geodienst/lighthousemap

Yep, saw that. Then I wonder: why are those attributes (seamark:light:{sequence, range, colour}) filled more often for lighthouses in Europe?

OpenStreetMap in general seems to have way more contributors from Europe: https://www.osmstats.neis-one.org/

But in this case perhaps much of that data came from a data import that didn't have compatibly-licensed data for the US.

TIL that German and Dutch share the same word for "Service". :)

There's many such words, since the languages share a common root. I'm Dutch but work for a German company and the main language is English. If we can't find a word, typically stuff not core work related, it's often quickest to say the German or Dutch word.

Anyone have any idea why the dataset doesn't include any the lighthouses along the Oregon coast? It has ones in California and Washington, but nothing for Oregon. Strange.

A bunch of Oregon lighthouses exist in OSM but they don't have specific data about the signal sequence yet so they aren't displayed on this map. (an example of a sequence would be 0.5+(3.5) which means the light is shown for 0.5 seconds and eclipsed for 3.5 seconds)

From the README: "it asks the Overpass API for all elements with an seamark:light:sequence attribute"

If you run the query here you'll see that there's not any lights with sequence data in Oregon yet. https://overpass-turbo.eu/s/1fnZ

If you run a new query you can find that there are plenty of lights on the OR coast with other attributes. (try searching for: "seamark:light:character=*" for instance)

I looked at some US coast guard data and found that while most light houses have data on the colour, characteristic, and period, it's rarer to have sequence data. I think for most purposes, just knowing that there's a white light that flashes every 4 seconds is good enough. Knowing that the light flashes for 0.5 seconds is probably less needed (unless you're making a map visualization)

If you really want to see the OR lighthouses you could find and add sequence data to lighthouses in OSM. Or you could fork this and write some code to visualize the lights that have some data (like colour and period) but not sequence, by making some assumptions/default values.

There's open issues for several US states https://github.com/geodienst/lighthousemap/issues Could simply be that the Overpass API query timed out for those regions.

Thanks for sharing that. My first thought was that there were none on the Great Lakes, which there's already an open issue for as well.

even ones in California are missing. For example this one: https://www.google.com/search?q=Point+Vicente+Lighthouse

Still very cool. Not complaining. Just passing on info :)

Was hoping to see more on the U.S. east coast

Lots missing in NC as well

Is this at all accurate?

San Francisco has dots in random places. But, to me, the most obvious missing lighthouse is the Montauk Point Light.

Yeah there are missing lights in Oregon and WA too. This is way off.

Then contribute to OSM. That's where they say the data is from.

TIL: Modern lighthouses no longer have a rotating light source. The “flashing” light is actually flashing. [1]

[1]: https://www.govtech.com/dc/articles/north-carolina-lighthous...

Nice idea but could do with a key. Why are some bigger? What do the colours mean? What's the blinking about?

It is a very literal encoding: the colors are the actual colors of the lights (unless you uncheck the "Show real colors" checkbox), they flash in the same pattern as the actual lights, and the radius of the circles is proportional to the nominal visible range (but I think they are smaller than the actual range [1]).

[1]: https://github.com/geodienst/lighthousemap/pull/9

Considering they're circles on a Mercator projection, they can't be the actual range, or at least they'd be off in at least one direction.

Yes, but they're relatively small so circles are not too bad as an approximation.

The Leaflet.Geodesic plugin can render (polygonal approximations to) geodesic circles correctly. Based on playing around with this demo [1] (drag the central marker to reposition, and drag the outer marker to resize), I don't think the deviation from circles would really be noticeable for most of the lights.

(Edit: some lights may only be illuminated in a particular sector, and there may obstacles blocking the view in some directions - arguably both of these are far more significant problems with the use of circles as markers)

[1]: https://blog.cyclemap.link/Leaflet.Geodesic/circle-interacti...

Oh nice! I thought there was some deeper meaning.

Looks like this is a work in progress. All the nav markers on buoys seem to be in place for the SF Bay, but none on the coastline or in Oregon. But hey, looks like it's on GitHub for anyone to submit patches.

The data comes from openstreetmap, so send your data there.

Very cool.

One thing I noticed on mobile - if you pan far enough in either direction such that the tiles end up wrapping / repeating, you lose all of the map markers.

I would make the point size dependent of the scale. When I zoom in I get huge balls. And I would make them not blink.

The size of the points shows the reported visible range, the colour and pattern of blinks represents how the light should appear. But this all depends upon the OSM data being entered correctly, and as https://github.com/geodienst/lighthousemap#readme notes:

"contains my best guess on how a light sequence will look based on these descriptions. However, it might be inaccurate, and it tries to do its best with the sometimes not entirely consistent data from OSM."

They blink as they blink in reality. This is the point of the map.

The point of the map is to remind you that lighthouses blink? I thought it was to show you where the lighthouses were.

I think they meant that the point is to show the blinking pattern (which is one very valuable piece of data when it comes to identifying a lighthouse).

Recommendation: Keep the sizes of the circles constant as one zooms in.

Very cool visualization, but the underlying dataset is very Euro-centric.

Even some on the Danube - in the middle of Europe...

Missing the Chicago Harbor Lighthouse...

Huh, nothing on Great Lakes.

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