Distance Mark

[HermanSchouten]

For 1.3 Change Guidance where it says “must” be associated to the structure to “may” be associated to a structure. Distance mark has a structure feature in it's definition: A distance mark indicates the distance measured from an origin and consists of either a solid visible structure or a distinct location without special installation.

The Boolean attribute Distance mark visible should control the presentation of the feature in S-101. In S-57 S-52 portrayal there are 2 symbols. 1 for physical and 1 for non physical (Also in S-4). This will be slightly different in S-101 where the boolean attribute is either visible or non visible. Currently this does not work in that manner.

Adding a parent feature results in extra workload in compiling and/or post conversion manual adjustments. It also results in clutter on the screen.

[HermanSchouten]

Is it correct that current draft presentation in S-101 for both visible and not visible DistanceMark is the following:

In S-57/S-52 there are the following two symbols, the first for Physical and the 2nd for Non Physical:

[DavidGrant-NIWC]

The 1.2 S-101 PC does not use the distanceMarkVisible attribute to affect the portrayal.

StructureEquipment	Mark (magenta circle)	Text offset	Text horizontal alignment
No association	Shown	3.15mm right of symbol	Start
Has association	Not Shown	7.02mm left of symbol	End

[HermanSchouten]

Hi David, thank you. I Guess this means there is no equivalent to a non physical Distance Mark in S-101 then.

S-52 portrayal was not aligned with S-4 . (Magenta for a physical feature with no effects to it's surroundings is a bit strange) S-101 Should/Could align better with S-4.
Should the distance unit of measurement also be taken into account?

[DavidGrant-NIWC]

The unit of measurement is taken into account in S-101.

See https://github.com/S-101-Portrayal-subWG/Working-Documents/issues/39 for the history of discussions regarding portrayal of distance mark. Proposed changes to the portrayal should be raised as new issues in that GitHub.

[HermanSchouten]

Thanks again David. I like Your example of a visible distance mark., that is a clear situation where you would have a Parent feature which is worth encoding. In our case 90% of the Distance marks are just minor posts which do not have a Parent feature. Or could be a Distance mark painted on the Quay (SLCONS) it is visible but without Parent feature. In such cases you still would want black instead of magenta display.

[DavidGrant-NIWC]

In such cases you still would want black instead of magenta display.

You would need to raise that issue in the PSWG GitHub: https://github.com/S-101-Portrayal-subWG/Working-Documents/issues

[JeffWootton]

Attribute distanceMarkVisible in the draft DCEG has been amended from optional to mandatory and the guidance amended to state that a structure feature may be associated to the distance mark (was formerly "must").

This change in the modelling and guidance is intended to allow for encoding of visible distance marks that have no structure feature at the position of the distance indication as outlined by Herman above. The mandating of distanceMarkVisible is intended to allow for this attribute to be considered in ECDIS portrayal. For example, the existing portrayal rules may be retained with the added condition that if the DistanceMark has distanceMarkVisible populated as True and is not in a Structure/Equipment relationship, then the (black) position circle at the position of the mark is retained in the display.

For consideration at S-101PT13 and possible action for the Portrayal Sub-Group.