Principles
Mapping A topic hierarchy provides a taxonomy structure to logically group concepts in support of lowering the barrier to finding data at varying granularity. Benefits include:
Easy aggregation across topic hierarchy levels
Easy to understand relationships (broad/narrow)
Fine grained filtering for search
Fine grained access control as required
Message queuing protocols and metadata benefit from topic hierarchy and organization
A single topic hierarchy which is interchangeable between discovery metadata, catalogues and topic hierarchy shall allow message queuing protocols topic allows for consistent resource discovery, subscription to the data described in the metadata item. data and event driven notifications/workflow
Topic hierarchy built from GTS is going to legacy will be temporary and used only to make GTS data available on WIS2
WIS2 hierarchy will be built gradually following the requirements of WMO domains.
Observations
NWP
…
WIS2 topic hierarchy and filename
Core hierarchy
scope/ data policy / data type
wis2/[core | recommended | other]/[ obs | nwp ]
Starts with WIS2 to mark the scope and syntax.
data policy will be high in the hierarchy because it imposes a distinction in access permissions
At the moment we have observations and nwp data, but we will add climate statistics and possibly other data types.
The hierarchy under this level is significantly different for obs and nwp.
obs/country/station-type/observation-type/
For observations, the topic hierarchy and the associated metadata shall be consistent with OSCAR metadata.
Country where the observing station is located. This is sometimes a problem with the sea stations.
station-type is about the location of the station (land, air, sea) and whether it is fixed or mobile: OSCAR surface
observation-type is about the type of observation (e.g. surface, upper-air)
Filename: WSI_[WSI value]_[timestamp].[data format]
...
WSI as shown in OSCAR surface
...
timestamp in the following format
...
Level | Name | Description | Value(s) | Example | |
|---|---|---|---|---|---|
1 | scope | Scope | Scope of topic hierarchy (fixed to |
|
|
2 | resource-type | Resource type | Type of resource being identified |
|
|
3 | data-policy | Data Policy | WMO Unified Data Policy category, provides distinction in access control/permissions |
|
|
4 | data-type | Data Type | Top level data type |
|
|
Examples:
wis2.data.core.observations
wis2.discovery-metadata.recommended.nwp
wis2.data.other.observations
wis2.monitoring-report.gts
Data Type Hierarchies
Data Type hierarchies vary significantly across data types (e.g. different for observations and NWP), and will be built gradually following the requirements of WMO domains.
Each WMO domain will also define filename conventions (basename, extension)
Observation Data Type
Level | Name | Description | Value(s) | Example | |
|---|---|---|---|---|---|
1 | country | Country | ISO 3166-2 code of country |
| |
2 | station-type | Station type | Station/platform type |
| |
3 | message-type | Message type | The type of message sent by the observation station |
|
airMobile.aircraft |
Examples:
wis2.data.core.observations.ca.landFixed.surface
wis2.data.core.observations.gr.landMobile.??
wis2.data.core.observations.it.seaFixed.??
wis2.monitoring-reports.wis2.observations.de.??
Alternative Proposal
This alternative proposal has the country code and center name higher up in the hierarchie. Could be extended with data policy
...
Filename conventions
Observations
Filename: WIGOS_{wsi}_{datetime}.{extension}
where:
Name | Description | Value(s) | Example(s) |
|---|---|---|---|
wsi | WIGOS station identifier |
|
|
datetime | Datetime |
| |
extension | Filename extension |
|
|
Examples:
WIGOS_0-454-2-AWSNAMITAMBO_20001111.bufr4
NWP
TBD
data format: grib2, nc
GTS topic hierarchy and filename
This is the current output of the TT-Protocols team
https://github.com/wmo-im/GTStoWIS2
| View file | ||
|---|---|---|
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Question to be answered.
...
Shall we make a topic structure directly with GTS headers (T/T/A/A/ii/CCCC )?
Related discussions
GTStoWIS2: https://github.com/wmo-im/GTStoWIS2/issues/9