WF Handle is a JSON Schema designed to describe Information-centric metadata for waveform digital objects.
It represents the information core of the PID-LAND architecture and provides a machine-actionable, FAIR-compliant description of waveform digital objects, independently of storage systems or delivery services.
WF Handle focuses on what the data is, while complementary schemas WF Provenance describe how the data was produced.
- Define a standardized metadata model for waveform digital objects
- Enable automatic validation using JSON Schema
- Support FAIR principles, with emphasis on:
- Findability (PID-first design)
- Accessibility (resolvable landing pages)
- Interoperability (shared vocabularies)
- Reusability (clear semantics and provenance links)
- Serve as the entry point metadata for:
- PID resolution
- Landing pages
- Metadata & provenance retrieval
- Manifest RO-Crate generation
WF Handle is information-centric, not system-centric.
Key principles:
-
PID-first
The persistent identifier is the primary access key, not the storage location. -
Decoupling
Metadata describes the object independently of:- file system layout
- archive structure
- delivery protocol
-
Single source of truth
The WF Handle is the authoritative metadata record referenced by:- provenance records
- search services
- aggregation mechanisms
-
Machine actionability
Every field is designed to be validated, parsed, and reused automatically.
A WF Handle represents a single logical waveform object:
- uniquely identified by a PID
- associated with spatial and temporal coverage
- linked to:
- a physical file
- a provenance record
- higher-level collections or datasets
It acts as the metadata anchor in the PID-LAND ecosystem.
- Schema type: JSON Schema (Draft 2020-12)
- Main type:
object - Extension policy: strict (
additionalProperties: false) - Required top-level fields include:
- identification
- descriptive metadata
- spatial and temporal coverage
- file reference
- provenance link
| Field | Type | Description |
|---|---|---|
@context |
object | Prefix mapping (dc, dcterms, schema, file) |
@type |
string | Fixed value: "WF Handle" |
dc:identifier |
string | Persistent identifier of the waveform |
dc:creator |
string | Creator or data owner |
dc:date |
string (date-time) | Creation or reference date |
dc:format |
string | File format (e.g. mSEED) |
dc:publisher |
string | Publishing organization |
dc:rights |
string | License or access rights |
dc:title |
string | Human-readable title |
dc:type |
string | Resource type |
dc:hasVersion |
string | Version identifier |
dc:description |
string | Descriptive text |
dc:provenance |
string (URI) | Link to provenance record |
dcterms:temporal |
object | Temporal coverage |
dcterms:spatial |
object | Spatial coverage |
dcterms:available |
string (date-time) | Availability date |
dcterms:dateAccepted |
string (date-time) | Acceptance date |
dcterms:isPartOf |
string | Parent collection |
file |
object | File description |
| Field | Type | Description |
|---|---|---|
dcterms:start |
string (date-time) | Start of coverage |
dcterms:end |
string (date-time) | End of coverage |
| Field | Type | Description |
|---|---|---|
schema:latitude |
number | Latitude |
schema:longitude |
number | Longitude |
schema:altitude |
number | Altitude (meters) |
| Field | Type | Description |
|---|---|---|
schema:name |
string | File name |
schema:url |
string (URI) | Resolvable file or landing URL |
The file reference is logical, not storage-specific.
- JSON Schema
- Enforces structure, required fields, and data types
- Prevents uncontrolled schema extensions
- SHACL
- Enables semantic validation on RDF graphs
- Useful for consistency checks (e.g. temporal logic)
WF Handle is designed to be safely validated in automated pipelines.
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"dcterms": "http://purl.org/dc/terms/",
"schema": "http://schema.org/",
"file": "http://schema.org/DigitalDocument"
},
"@type": "WF Handle",
"dc:identifier": "11099/6b8414a2-fb66-11f0-b5e4-0242ac120007",
"dc:creator": "INGV",
"dc:date": "2024-04-09T10:39:40Z",
"dc:format": "application/vnd.fdsn.mseed",
"dc:publisher": "INGV",
"dc:rights": "open access",
"dc:title": "Waveform ACER HNE",
"dc:type": "Dataset, Waveform",
"dc:hasVersion": "1.0",
"dc:description": "Waveform data for station ACER channel HNE",
"dc:provenance": "https://hdl.handle.net/11099/.../?urlappend=provenance",
"dcterms:temporal": {
"dcterms:start": "2024-04-09T10:39:40Z",
"dcterms:end": "2024-04-10T00:00:01Z"
},
"dcterms:spatial": {
"schema:latitude": 40.7867,
"schema:longitude": 15.9427,
"schema:altitude": 690
},
"dcterms:available": "2024-04-10T00:00:01Z",
"dcterms:dateAccepted": "2024-04-10T00:00:01Z",
"dcterms:isPartOf": "IV Network Waveforms",
"file": {
"schema:name": "IV.ACER..HNE.D.2024.100",
"schema:url": "https://hdl.handle.net/11099/data/ACER_HNE_20240409.mseed"
}
}Relationship with WF Provenance
WF Handle answers: What is this digital object?
WF Provenance answers: How was this object generated?
Together they implement a PID-centric, information-centric metadata architecture supporting reproducible science, long-term preservation, and FAIR data management.