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iho-ohi / S-102-Product-Specification

It is opened to develop S-102 Bathymetric Surface Product Specification. The contents of this repository are not offical publication in force, therefore please check the final version on the IHO website.
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ExchangeSet - S100_DatasetDiscoveryMetadata - purpose #88

Open RohdeBSH opened 2 months ago

RohdeBSH commented 2 months ago

Hi all,

Why is the "purpose" in S-102 mandatory? There is maybe a good reason, I just don't know. But why are all values of S100_Purpose allowed? Does it make sense to allow values like "update", "reissue" or "delta". Is it not rather the case that S-102 is always made available in full? So, only as "newDataset" or "newEdition"?

https://github.com/iho-ohi/S-102-Product-Specification/blob/cffb0c33b6873d9a0ebcb61117a0e130c56d1c64/sources/3.0.0/sections/12-metadata.adoc?plain=1#L358C1-L363C22

RohdeBSH commented 2 months ago

Hi, The question has been partially resolved. I still find the difference between “newDataset” and “newEdition” interesting. Is this distinction really necessary? A dataset with a younger "issueDate" & "issueTime" always completely overwrites the older one. Maybe someone can explain to me whether and how the ECDIS then acts differently.

giumas commented 2 months ago

@RohdeBSH, it would be beneficial for the clarity of this ticket a short description on how the "question has been partially resolved".

RohdeBSH commented 2 months ago

Hi @giumas ,

Maybe it wasn't the correct wording. In the latest version of S-102 ed. 3.0.0 (Branch - Developing) the values "update", "reissue" & "delta" are no longer allowed. See https://github.com/iho-ohi/S-102-Product-Specification/blob/cffb0c33b6873d9a0ebcb61117a0e130c56d1c64/sources/3.0.0/sections/12-metadata.adoc?plain=1#L631

Perhaps I had overlooked it or looked in an old S-102 edition. Therefore, it has been partially resolved.

The question that now arises is what ECDIS does fundamentally differently with "newDataset" and "newEdition". So is it even necessary to differentiate between "newDataset" and "newEdition" in the S-102? In the end, it is a copy and replace in both cases. Okay, if it is a "newDataset" there is no need to check the "issueDate"/"issueTime".

if (oldDatasetFile.exists() == true){
    if(checkIssueDateAndIssueTimeYounger(oldDatasetFile, newDatasetFile ) == true){
         //newDatasetFile is younger
        copyAndReplace(newDatasetFile )
    }
} else {
     copy(newDatasetFile )
}

I can always execute the pseudo program code above, regardless of the "purpose" "newDataset" or "newEdition".

I hope this answers your question.