Merge pull request #19 from pdowler/caom25

draft radio changes plus additional changes for CAOM-2.5

.github/workflows/gradle.yml

@@ -17,7 +17,7 @@ jobs:
         java-version: 11
 
     - name: validate CAOM datas model version(s)
-       run: ./gradlew --info clean checkstyleTest test
+      run: ./gradlew --info clean checkstyleTest test
 
     - name: generate HTML documentation
       run: ./gradlew --info clean xslt

Changelog.md

@@ -0,0 +1,61 @@
+# CAOM changes
+The following is a brief summary of changes in the current draft version (2.5).
+
+## general changes 
+- change `Plane.position.bounds` to be mandatory
+- change `Plane.energy.bounds` to be mandatory
+- change `Plane.time.bounds` to be mandatory
+- change `Plane.polarization.states` to require at least 1 value
+
+The above changes mean that each of position/energy/time/polarization objects have one mandatory field and 
+queries with something like `Plane.position.bounds is not null` can be used to detect if the object is present.
+
+- add `ArtifactDescription` entity to support providing descriptions with links (eg in a DataLink output)
+- add `Artifact.descriptionID` to refer to a shared `ArtifactDescription`
+- add `Proposal.reference` as optional proposal metadata (URI to web page, paper, etc)
+
+- split `Entity` into a base `Entity` class with main properties and a `CaomEntity` suitable for having 
+child entities (by composition); one or both could be extracted and re-used in other models (TBD)
+
+## radio support
+For radio observations, many properties such as field-of-view, spatial and spectral resolution are dependent on frequency. Modern, wideband facilities can have large frequency-dependent variation in these properties within a single observation.
+
+- add `Plane.position.minBounds` (Shape) to describe variable coverage (bounds is already max bounds)
+- add `Plane.position.maxAngularScale` (Interval) to describe min/max scale of signal/objects in the data; could be in Plane.metrics?
+- add `Plane.energy.resolution` (double) to describe the absolute resolution (representative value, probably mean/pixel)
+- add `Plane.energy.resolutionBounds` (Interval) to describe the min/max absolute resolution when it varies across the data
+- add `Plane.time.exposureBounds` (Interval) to describe the min/max absolute exposure time when it varies across the data
+- change `Plane.energy.restwav` to `Plane.energy.rest` so the name makes sense with different profiles (quantities and units)
+- remove `Plane.position.timeDependent` as it was only used to explain why Plane.position.bounds was null because of tracking mode
+
+- add `Observation.telescope.trackingMode` and refer to a non-existent IVOA vocabulary to describe the 
+  tracking/pointing of the telescope during the observation; null indicates sidereal tracking (for backwards compat)
+
+- add `Plane.uv` (Visibility) to describe UV-plane (expect: only used when dataProductType=visibility)
+- add `Plane.uv.distance` (Interval) to describe the min and max distance in the UV plane
+- add `Plane.uv.distributionEccentricity` (double); mandatory or optional within Visibility?
+- add `Plane.uv.distributionFill` (double); mandatory or optional within Visibility?
+
+- change `Plane.polarization.states` to refer to a (non-existent) vocabulary (replaces PolarizationState enum) that could be extracted from WCS, ObsCore, and community usage/extensions
+
+## identifiers
+- replace `Observation.observationID` (String) with `Observation.uri` (URI) to be the complete self contained identifier; values would be used in `DerivedObservation.members` to refer to other observations
+
+- replace `Plane.productID` (String) with `Plane.uri` (URI) to be the complete self-contained identifier; values would be used in `Plane.provenance.inputs` to refer to other planes
+- remove `Plane.creatorID` because it is essentially redundant vs Plane.uri
+
+A `publisherID` value is strictly outside the core model because the value must be changed (generated) when CAOM metadata is synced from one _publisher_ to _a differnt publisher_. 
+
+## reconcile with IVOA data models
+
+- change `Plane.dataProductType` to refer directly to the IVOA product-type vocabulary
+- change `Artifact.productType` to refer directly to the IVOA DataLink Core (semantics) vocabulary
+- change `Plane.observable.ucd` to refer directly to IVOA UCD1+
+
+- add `Plane.position.calibration` and refer to a non-existent IVOA vocabulary that could be extracted from the ObsCore optional section
+- add `Plane.energy.calibration` (as above)
+- add `Plane.time.calibration` (as above)
+- add `Plane.observable.calibration` (as above)
+
+- remove SampledInterval in favour of separate Interval and Interval[] columns in Energy, Time, CustomAxis
+- remove MultiPolygon in favour of separate Polygon and MultiShape columns; SegmentType and Vertex removed (unused)