DiggsCore.xsd

<?xml version="1.0" encoding="utf-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:diggs="http://diggsml.org/schemas/3"
  xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning"
  vc:maxVersion="1.1" vc:minVersion="1.0" elementFormDefault="qualified"
  targetNamespace="http://diggsml.org/schemas/3" version="3.0.0">

  <!-- ================================================================ -->
  <!-- MAIN SCHEMA FILE FOR DIGGS CORE GEOTECHNICAL PROFILE             -->
  <!-- ================================================================ -->
  <!-- This is the schema file for the DIGGS Core profile, which       -->
  <!-- provides essential geotechnical data exchange capabilities for  -->
  <!-- basic site investigations including boreholes, samples, and     -->
  <!-- common field and laboratory tests. This profile omits extended  -->
  <!-- and specialty modules for applications requiring only core      -->
  <!-- functionality.                                                   -->
  <!-- ================================================================ -->


  <!-- ================================================================ -->
  <!-- INCLUDE COMMON SCHEMA FILES                                      -->
  <!-- ================================================================ -->
  <!-- Common modules provide foundational types and structures used    -->
  <!-- throughout the DIGGS Core profile.                               -->
  <!-- ================================================================ -->

  <include schemaLocation="core/AbstractTypes.xsd">
    <annotation>
      <documentation>Includes all abstract base types and elements that form the foundation of DIGGS
        objects. This module contains the inheritance hierarchy for the principal DIGGS object
        classes (project, program, samplingFeature, samplingActivity, sample, observation,
        measurements, constructionActivity and groups, and other core abstractions.</documentation>
    </annotation>
  </include>

  <include schemaLocation="core/Common.xsd">
    <annotation>
      <documentation>Includes common concrete types, reference element and enumerations used
        throughout DIGGS including Role, Remark, AssociatedFile, BusinessAssociate, Parameter,
        Specification, and other frequently-used components.</documentation>
    </annotation>
  </include>
  <include schemaLocation="core/MeasureTypes.xsd">
    <annotation>
      <documentation>Includes all measurement and quantity types with proper units of measure.
        Provides type-safe measurements for length, mass, pressure, temperature, angle, velocity,
        and other physical quantities used in geotechnical data. Based on the Energistics Units of
        Measurement Dictionary quantity classes and units with DIGGS-specific
        extensions.</documentation>
    </annotation>
  </include>

  <include schemaLocation="core/LinearReferencing.xsd">
    <annotation>
      <documentation>Includes types and elements for ISO-compliant linear referencing systems.
        Enables definition of depth-based, station/offset, and other linear coordinate systems for
        locating measurements and observations along boreholes and other linear sampling features.
        Supports coordinate transformations between different linear reference
        methods.</documentation>
    </annotation>
  </include>

  <include schemaLocation="core/LocalReferencing.xsd">
    <annotation>
      <documentation>Includes types for local coordinate reference systems (CRS) that are relative
        to sampling features. Supports engineering coordinate systems, project-specific datums, and
        custom reference frames. Enables proper documentation of coordinate transformations between
        local and absolute (geodetic) reference systems.</documentation>
    </annotation>
  </include>

  <include schemaLocation="Dictionary_diggs.xsd">
    <annotation>
      <documentation>Includes dictionary and controlled vocabulary support based on GML dictionary
        schema. Provides mechanisms for defining and referencing standardized term lists (e.g., USCS
        soil classifications, rock type lists), ensuring consistent terminology across data
        exchanges. Supports both internal and externally-referenced vocabularies.</documentation>
    </annotation>
  </include>

  <!-- ================================================================ -->
  <!-- INCLUDE CORE SCHEMA FILES                                        -->
  <!-- ================================================================ -->
  <!-- Core modules provide the essential geotechnical features and     -->
  <!-- procedures for basic site investigation data exchange.           -->
  <!-- ================================================================ -->

  <include schemaLocation="core/Core.xsd">
    <annotation>
      <documentation> Includes core geotechnical features: projects, sampling features,
        sampling activities and samples, observations, measurements, equipment, geometry
        and time objects and related elements. This module provides the fundamental data
        structures for documenting site investigations including project metadata, borehole
        construction details, sample descriptions, field testing, and laboratory analysis. This
        is the heart of the DIGGS Core profile. </documentation>
    </annotation>
  </include>

  <include schemaLocation="core/CoreProcedures.xsd">
    <annotation>
      <documentation>Includes standard testing procedures commonly used in geotechnical practice.
        Provides concrete implementations of frequently-performed field tests (SPT, CPT, vane shear,
        permeability tests) and laboratory tests (Atterberg limits, grain size analysis, moisture
        content, unit weight, unconfined compression, direct shear, consolidation). Each procedure
        type includes appropriate properties for test parameters and results.</documentation>
    </annotation>
  </include>

  <!-- ================================================================ -->
  <!-- IMPORTS                                                          -->
  <!-- ================================================================ -->

  <import namespace="http://www.opengis.net/gml/3.2" schemaLocation="core/gml3.2Profile_diggs.xsd">
    <annotation>
      <documentation>Import of the DIGGS profile of GML 3.2.1. This profile includes the essential
        GML components needed for DIGGS Core features including geometry, temporal objects, units of
        measure, and feature collections. The GML profile is streamlined to include only those
        components actually used in DIGGS, reducing schema complexity.</documentation>
    </annotation>
  </import>

  <import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="core/xml.xsd">
    <annotation>
      <documentation>Import of the XML namespace to support the xml:lang attribute for language
        specification throughout DIGGS documents. This enables internationalization support for
        multi-language data exchange.</documentation>
    </annotation>
  </import>

  <!-- Uncomment this import to utilize deprecated objects from the diggs_geo namespace -->
  <!-- <import namespace="http://diggsml.org/schemas/3/geotechnical" schemaLocation="deprecated/Diggs_geo_deprecated.xsd"/>  -->

  <!-- ================================================================ -->
  <!-- DIGGS CORE ROOT ELEMENT                                          -->
  <!-- ================================================================ -->
  <complexType name="DiggsType">
    <annotation>
      <documentation>The complex type for the DIGGS root element. Extends GML's AbstractFeatureType
        to provide a feature collection that can contain multiple projects and all associated data
        objects. The structure allows for flexible organization of data while maintaining
        referential integrity through gml:id and xlink:href relationships.</documentation>
    </annotation>
    <complexContent>
      <extension base="gml:AbstractFeatureType">
        <sequence>
          <element maxOccurs="1" minOccurs="1" name="documentInformation"
            type="diggs:DocumentInformationPropertyType">
            <annotation>
              <documentation>Required element containing metadata about the DIGGS document itself
                including creation date, originating organization, software used, coordinate
                reference systems employed, and other document-level information. This element must
                appear exactly once and should be the first element in the document
                content.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="project"
            type="diggs:ProjectPropertyType">
            <annotation>
              <documentation>Container for Project features. Projects serve as the primary
                organizational unit for geotechnical investigations and construction activities.
                Each project typically represents a single site investigation, construction project,
                monitoring or research program. Most other features in the document will reference
                back to their associated project(s).</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="samplingFeature"
            type="diggs:SamplingFeaturePropertyType">
            <annotation>
              <documentation>Container for SamplingFeature elements. Sampling features are physical
                locations or objects where observations and measurements are made or activities
                conducted, including boreholes, test pits, monitoring wells, CPT soundings, surface
                sample locations, geophysical lines, and other investigation features. These
                features define the spatial framework for data collection.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="samplingActivity"
            type="diggs:SamplingActivityPropertyType">
            <annotation>
              <documentation>Container for SamplingActivity features. Sampling activities document
                the collection, subsampling, or aggregation of physical samples. Each activity
                records the time, location, methods, equipment, and environmental conditions under
                which samples were obtained, along with recovery information and sample production
                details.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="sample" type="diggs:SamplePropertyType">
            <annotation>
              <documentation>Container for Sample features. Samples are physical specimens of
                material (soil, rock, water, grout, etc.) collected from sampling features or
                created for a project that are destined for analysis and testing. Each sample
                records its physical condition and chain of custody, and links to the sampling
                activity that produced it.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="observation"
            type="diggs:ObservationSystemPropertyType">
            <annotation>
              <documentation>Container for ObservationSystem features. Observation systems organize
                qualitative descriptions and interpretive classifications along sampling features or
                samples. Examples include lithologic descriptions, discontinuity logs, stratigraphic
                interpretations, and other qualitative characterizations. Each system contains
                multiple zones or regions (observations) with consistent description
                methodology.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="measurement"
            type="diggs:MeasurementPropertyType">
            <annotation>
              <documentation>Container for Measurement features including Tests, MaterialTests, and
                Monitors. These features document quantitative testing and monitoring activities.
                Tests are field or lab procedures where the results are relevant to spatial
                locations. MaterialTests are laboratory procedures on samples that have no location
                relevance (eg. tests on grout samples). Monitors are long-term measurements at
                specific locations where the results vary with time.</documentation>
            </annotation>
          </element>

          <element maxOccurs="unbounded" minOccurs="0" name="group" type="diggs:GroupPropertyType">
            <annotation>
              <documentation>Container for Group features. Groups provide flexible mechanisms for
                organizing and collecting related features into logical sets. Examples include
                grouping all boreholes from a specific investigation phase, all tests on a
                particular geologic unit, or all monitoring activities in a specific area.
              </documentation>
            </annotation>
          </element>
        </sequence>

        <attribute ref="xml:lang">
          <annotation>
            <documentation>Specifies the default language for text content throughout the DIGGS
              document. Individual features can override this with their own xml:lang attributes. If
              not specified, English is assumed. Use ISO 639 language codes (e.g., "en" for English,
              "fr" for French, "es" for Spanish).</documentation>
          </annotation>
        </attribute>
      </extension>
    </complexContent>
  </complexType>
</schema>