Added `UpdateAggregation` [DCEG GAP 1.3.0_2.0.0 Row 41]

[DavidGrant-NIWC]

[alvarosanuy]

Hi Dave, sadly we do not have a version of CARIS to produce S-101 products to Ed 1.3.0 at this point in time. we hope this changes by the end of the week, but we won't be able to give you any test data until next week. As far as you can implement something based on the theory below, we could then fine tune all that for PC 1.5.0

The 2 main use cases described in the DCEG are:

[DavidGrant-NIWC]

Understood - we'll try to move forward with what we have. I just started looking into this this evening; I'm not sure that any portrayal changes will be needed since the aggregation(s) don't affect the portrayal of the individual UpdateInformation features. I'll look at it some more tomorrow.

I do think the DCEG guidance may need a little updating:

• I believe when a move is portrayed the encoding of the curve connecting the new and old location should be optional (at the discretion of the encoder).
• I think I understand what the highlighted entry is getting at, but I still find it confusing. It makes it seem like the container of an UpdateAggregation has to have updateType=modify. However, the container can alternatively have updateType=move. Clause 25.20 has a better description.

[alvarosanuy]

I'm not sure that any portrayal changes will be needed since the aggregation(s) don't affect the portrayal of the individual UpdateInformation features.

I tend to agree; my understanding is that it would help with the presentation of overall update action to the mariner in ECDIS [e.g. a layered approach, where a "move' is identified as the top-level update action, and their constituents (delete & insert) would be listed below and simultaneously highlighted when the top-level layer is selected by the user].

[DavidGrant-NIWC]

No changes are required but error checking will be added to ensure when the geometry type is None the updateType is either modify or move.

Supported geometries by updateType

updateType	Point	MultiPoint	Curve	Surface	None
1: insert	valid	not valid	valid	valid	not valid
2: delete	valid	not valid	valid	valid	not valid
3: modify	valid	not valid	valid	valid	valid (no portrayal)
4: move	not valid	not valid	valid	not valid	valid (no portrayal)