Incorrect scale line - incorrect distance value - Githubissues

OpenSeaMap / online_chart

OpenSeaMap fullscreen browser chart.

http://map.openseamap.org/

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Incorrect scale line - incorrect distance value #101

Closed xintrea closed 5 years ago

xintrea commented 5 years ago

Hi!

Your scale line (at corner of map) is incorrect.

See at this image: OSM vs OSeaM

Real distance of 1km your engine show as 1nmi. And your 1 km is too small relatively real 1km.

I compared OpenSeaMap scale line with OpenStreetMap, YandexMaps, GoogleMaps. All this map service show correct distance. But OpenSeaMap show incorrect.

Please, fix it.

Nautic commented 5 years ago

Hi, thanks for your error message. Please can you add a permalink for the OpenSeaMap and OpenStreetMap position so we can check the latitude? Thanks, Markus

xintrea commented 5 years ago

If put locality at center of browser windows:

OpenStreetMap: https://www.openstreetmap.org/#map=12/59.9955/29.7513

OpenSeaMap: http://map.openseamap.org/?zoom=13&lat=59.99936&lon=29.73647&layers=BFTFFFFFFTF0TFFFFFFFFF

mojoaxel commented 5 years ago

Looks like the distance-indicator is off by one zoom-level in OpenSeaMap.

wschildbach commented 5 years ago

I think it is off by more -- if you put both an OpenStreetMap and an OpenSeaMap display at equal scale, the ScaleLine has a different size not a factor of two. The OpenLayers ScaleLine module has seen a number of bug fixes relating to scale. We should consider updating to a newer version of openLayers.

Nautic commented 5 years ago

Mit gleichem Zoomlevel und gleichem Kartenmittelpunkt sind die Kartenausschnitte in OSM (OL ?) und OpenSeaMap (OL 2) identisch. Aber die Skalen zeigen in OSM 500m, in OpenSeaMap 1km, und die Skalenlänge differiert von OSM mit 12mm für 500m zu OpenSeaMap mit 13,5mm für 1km.

Ich vermute den Fehler im Skript für den Massstab (scale). Siehe #17

Update auf OL-6 wäre sinnvoll - aber ein anderer Issue. Zum geplanten OL-3-Update (2013) siehe Issues OL-3

wschildbach commented 5 years ago

With an additional patch (PR forthcoming), this is what the ScaleLine looks like:

wschildbach commented 5 years ago

Hi @xintrea , can you take another look whether the problem is resolved and close the bug if it is?

wschildbach commented 5 years ago

This issue is fixed -- we can close the issue. @Nautic kannst Du das zumachen?

Nautic commented 5 years ago

Vielen Dank für die Korrektur, und für die Verbesserung im Layout :-) In z=14,15,17,18 finde ich das Layout hilfreich.

In z=3..11 könnte die Linie deutlich länger sein (Faktor 5?) In z=12,13,16 könnte die Linie noch länger sein (Faktor 2..3?) In z=15 ist das Verhältnis von nmi und km noch ungünstig (nmi grösser)

wschildbach commented 5 years ago

moved last comment into new feature #132 and closing this one.