Documentation

ODM2 Documentation Index

The next version of the Observations Data Model.

ODM2 Architecture

ODM2 is organized with a "core" schema and multiple "extension" schemas that extend the functionality of the core. The following sections cover some overarching concepts for ODM2 and then focus on specific entities within the ODM2 Core schema and ODM2's extension schemas.

ODM2 inherits extensively from ODM 1.1.1, which was developed as part of the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) project (Horsburgh et al., 2008; Horsburgh and Tarboton, 2008). ODM2 also inherits features from the Open Geospatial Consortium (OGC) Observations & Measurements (O&M) standard (Cox, 2007a; Cox 2007b; Cox 2011a; Cox 2011b).

ODM2 Software Ecosystem

ODM2 is both an information model and a supporting software ecosystem. For more information about supporting software development for ODM2, visit the ODM2 Meta Repository that details all of the tools under development for ODM2.

ODM2Core Entities

The following are entities in the ODM2 Core schema:

• Actions - Actions are performed by people and may have a result.
• Datasets - Enables grouping of results into a larger dataset.
• FeatureActions - Provides flexible linkage between Actions and the SamplingFeatures on which or at which they were performed.
• Methods - The procedure used to perform an action.
• Organizations - A group of people.
• People - Individuals that perform actions.
• Processing Levels - Levels to which data have been quality controlled.
• Related Actions - Enables specifying relationships among Actions (e.g., workflows, etc.)
• Results - The result of an action.
• Sampling Features - Where or on what an action was performed.
• Taxonomic Classifiers - Terms for classifying results.
• Units - Units of measure.
• Variables - What was observed.

ODM2 Extensions

The following are extensions to the ODM2 Core:

• Annotations (Schema Diagram) - Data qualifying comments and annotations on other entities.
• Controlled Vocabulary (Schema Diagram) - Entities for enforcing CVs.
• Data Quality (Schema Diagram) - Information about the quality of observations.
• Equipment (Schema Diagram) - Information for managing field sensors, sampling, or laboratory equipment.
• ExtensionProperties (Schema Diagram) - A general extensibility mechanism for ODM2 (adding new attributes).
• External Identifiers (Schema Diagram) - Linking entities in ODM2 to external repositories.
• LabAnalyses (Schema Diagram) - Information for managing ex situ, sample-based data.
• Provenance (Schema Diagram) - Information about versions and provenance.
• Results (Schema Diagram) - Values for observation results.
• Sampling Features (Schema Diagram) - Information about sampling features on which observations are made.

Additional Concepts

The following are additional concepts that are important.

• Controlled Vocabularies: Approach, validation, web hosting
• Geography, location, and spatial offsets
• Support, Spacing, and Extent
• ...

ODM2 Best Practices

The following are articles that describe best practices for using ODM2:

• Preparing Site information
• Preparing Variable information
• Handling dates and times
• Use of NoData values
• Encode data reported as trace concentration
• Encode data for co-located sensors
• Encode data for which the exact date is unknown

New Features of ODM2

We are compiling a brief description of new features of ODM2 to answer the question: "What can I do now that I couldn't do with ODM 1.1.1?"

Project WIKI

For more information about the project, visit the wiki.

View Diagrams of the ODM2 Schema

HTML-based diagrams for the current version of the ODM2 schema are at:

• Current Version

References

See a full list of ODM2 related references.