mDIS User Documentation

IGSN Descriptive Schema - work in progress

My personal notes about IGSN Descriptive Schema - which has no normative power whatsoever.

This page is under construction.

This was just my first approach to the topic "XML schema as a basis for IGSN implementation", 2022.

Normative reference for IGSN Data Definition

The IGSN for Geosamples was specificied as XML Schema.

The Schema for Sample Medata is described at http://schema.igsn.org/description/1.0/resource.xsd (opens new window).

Focus on the Problem domain, "Samples" or "Specimens"

Q: How well did the schema designer represent the problem domain?

A: Not very well. For example, the term sample does not appear as "root level" element of the schema.

Rather, the root level element is called "resource" element. This is a "container" for the sample metadata. A resource is a broader classification than a sample. It represents the "sample", and more.

According to the .xsd files, a resource must provide 1 term from "ODM2 vocabulary", (= "specimen" OR "samplingfeature"):

  • "Specimen": automated, core, coreHalfRound, corePiece, coreQuarterRound, coreSection, coreSectionHalf, coreSub-Piece, coreWholeRound, cuttings, dredge, foliageDigestion, foliageLeaching, forestFloorDigestion, grab, individualSample, litterFallDigestion, orientedCore, petriDishDryDeposition, precipitationBulk, rockPowder, standardReferenceSpecimen, terrestrialSection, thinSection, other, unknown
  • "Samplingfeature": borehole, crossSection, CTD, depthInterval, excavation, fieldArea, flightline, interval, observationWell, profile, quadrat, scene, shipsTrack, site, soilPitSection, specimen, streamGage, trajectory, transect, traverse, waterQualityStation, weatherStation
  • plus 0-N additional terms from any vocabulary.

Confusingly, the "Specimen" is described in "sampleType" (opens new window).xsd.

A rather weird collection of sample types is used in the IGSN.

These ideas seem to stem from the Observation data model 2 (opens new window), an initiative by academics from 2015. (Its repo https://github.com/ODM2/ODM2 (opens new window) had 49 stars on Github in 2022).

Modified XML Schema for IGSN

Speculation: To overcome this weirdness, a modified XML Schema is being created.

In there, some modified IGSN-related .xsdfiles are available (for registered uers) as source code in the IGSN Schema Repository at GFZ Potsdam.

The repository exists as a private GitLab repository (opens new window). Some files are also available on the public internet, in slightly older versions and/or slightly modified pathnames:

There is also a registration schema but it is poorly documented (and designed).

Scratchpad begins

Everything below this block is pure speculation.

This GFZ-Gitlab repo exists since 2021, and emerged from a restarted development initiative, jointly with a few developers from other GFZ Groups.

The repo only contains XML Schema .xsd files, and a few Markdown files. Probably these are the "official" .xsd files, meant to be used in the future. I haven't checked if they differ from those at GFZ's Dataservices.

In any case here is the repo as .zip with all .xsd Files attached.

The contents of the Repo as of 2022-05-19:


./igsn-main/schemata:
DescriptiveMetadata
DescriptiveMetadataGFZSample
Registration

./igsn-main/schemata/DescriptiveMetadata/1.3:
include
resource.xsd

./igsn-main/schemata/DescriptiveMetadata/1.3/include:
accessType.xsd
collectionType.xsd
contributorType.xsd
featureType.xsd
geometryType.xsd
identifierType.xsd
materialType.xsd
methodType.xsd
relationType.xsd
resourceType.xsd
sampleType.xsd
sridType.xsd


./igsn-main/schemata/DescriptiveMetadataGFZSample/1.3:
classifications.xsd
relatedIdentifierType.xsd
relationType.xsd
sample.xsd


./igsn-main/schemata/Registration/1.1/include:
igsn-dateType-v1.1.xsd
igsn-eventType-v1.1.xsd
igsn-identifierType-v1.1.xsd
igsn-nameIdentifierScheme-v1.1.xsd
igsn-relatedIdentifierType-v1.1.xsd
igsn-relationType-v1.1.xsd
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