Coordinates--True Geography or Ship Orientation |
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Slice in the xy plane through a shipwreck.
These are geographic coordinates (east-west and
north-south) and show the
actual orientation of the wreck on the seafloor.
These coordinates would be used for survey and
other operations. These could be
latitude/longitude, or a projected from like UTM
which is better for mapping and is what the Army
and Marines use for land maps. Sections through the point cloud along the axes will not provide a good depiction of the ship because the widths of the ship sides will be exagerrated, but this shows the true location. |
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Slice in the xy plane through the same shipwreck after rotation of the point cloud. The x-axis is the long dimension, and 0 is at one end of the ship. Since neither the bow nor the stern is vertical, this is only approximate. The 0 on the y axis is the approximate centerline of the ship, so that slices in the yz plane should be roughly symmetrical. |
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Slice in the xy plane through a ship displayed in a museum. The coordinates reflect the orientation of the ship, which is arbitrary but reflects the symmetry of the ship. The ship's boat is in the upper left. |
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Slices through a ship.
Top slice uses the real coordinates, but the slice cuts diagonally through the ship and the geometry is greatly distorted.
Bottom slice rotates the ship, and the view gives a good longitudinal profile of the vessel. |
Control slices through the point cloud.
last revision 2/9/2016