Distance calculations
Method 1 - utilising surfboard and mobile phone.
The surfboard is 11.3 cinclus feet, or 3.70 metres long.
When the surfboard is beside the buoy and parallel to the shore it subtends the same angle as my mobile phone held at arms length.. The mobile phone is 0.04 m wide and eye to phone distance is 0.72m.
So the distance to the buoy is 3.7 x 0.72 / 0.04 ie 66.6m, or about 63 m from High Water Mark.
Method 2 - utilising sightlines.
The sightlines from the corner of Sorrento Terrace to the Lead Mines chimney, and from the Hut to Bray Baths intersect at the buoy. Drawing these on openstreetmap.org and connecting the intersection of the two lines to the shore displays a distance of, yes, 63m
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1 comment:
Nice work, I was wondering what these sightline ways were in the osm data.
Next question is how to tag it.
Have a look at this page for maritime tagging:
http://wiki.openstreetmap.org/wiki/Proposed_features/marine-tagging#Buoys_and_Beacons_.28Q.29
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