Topic hierarchy and filename

Principles

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:
1. Easy aggregation across topic hierarchy levels
2. Easy to understand relationships (broad/narrow)
3. Fine grained filtering for search
4. 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 message queuing protocols topic allows for consistent resource discovery, subscription to data and event driven notifications/workflow
Topic hierarchy built from GTS 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
1. Observations
2. NWP
3. …

WIS2 topic hierarchy and filename

Core hierarchy

	Level	Name	Description	Value(s)	Example
1	scope	Scope	fixed to `WIS2`	`WIS2`	`WIS2`
2	data-policy	Data Policy	articulates the WMO Unified Data Policy, provides distinction in access control/permissions	`core` `recommended` `other`	`core`
3	data-type	Data Type	Category	`observations` `nwp` …	`observations`

Examples:

wis2.core.observations

wis2.recommended.nwp

wis2.other.observations

Level 3 Data Type Hierarchies

Level 3 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	category	Category	Data category	`observations` …	`observations`
2	country	Country	ISO 3166-2 code of country	https://en.wikipedia.org/wiki/ISO_3166-2	`ca`
3	station-type	Station type	Station/platform type	https://codes.wmo.int./wmdr/_FacilityType	`landFixed`
4	message-type	Message type	The type of message sent by the observation station	?	?

Examples:

wis2.core.observations.ca.landFixed.??

wis2.core.observations.gr.landMobile.??

wis2.core.observations.it.seaFixed.??

Filename conventions

Observations

Filename: WIGOS_{wsi}_{datetime}.{extension}

where:

Name	Description	Value(s)	Example(s)
wsi	WIGOS station identifier	OSCAR/Surface Catalogue	`0-454-2-AWSNAMITAMBO`
datetime	Datetime	RFC33339	`2000-11-11` `20001111` `2000-11-11T0932` `2000-11-11T09:32:11Z`
extension	Filename extension	`bufr4` `geojson` `nc` `tac` `xml`	`geojson`

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

Question to be answered.

Given that GTS will be dismissed does it make sense to develop a topic hierarchy based on GTS headers?

Shall we make a topic structure directly with GTS headers (T/T/A/A/ii/CCCC )?

Related discussions

wis2node: https://github.com/wmo-im/wis2node/issues/31