Vocabulary Mapping

Folder of vocabulary mapping resources at MMI.

Definition

Vocabulary Mapping is the process of relating the terms of two or more vocabularies. Different kind of relations can be depicted depending on the system used to represent the vocabularies and the relations. Some examples are:

  • Taxonomy relations: Specific and general relations. For example, A is more general than B.
  • Tree relations: Parent-children relations A has a leaf B.
  • Graphs relations: Node A is connected to Node B
  • Thesaurus relations: Narrower-than, broader than, same as, similar-to. A is broader than B
  • Conceptual model relations: Class-subclass relations or class-individuals relations. For example, A is superclass of B

The relation representation is also predetermined by the model or system where the mapping is talking place. If the representation mechanism is a table, writing the two terms in the same row, could mean that they are the same. If a graph is used, a line connecting two terms could also represent the "same as" relation. The difficult part of this process is how to represent the relations in a format that a computer program can understand and use (ror example, XML).

MMI Strategy

To simplify the integration of vocabularies at MMI we use three relations: sameAs, narrowerThan, and broaderThan, and we use OWL as the medium to express both the vocabularies and the mapping relations. Expressing vocabularies (which are originally in different formats) in OWL is called harmonization, which is the step prior to mapping. Mapping exercises and related resources at MMI can be found here.

Mapping of marine vocabularies allows discovery of data sets, especially mapping between Parameter Discovery Vocabularies (PDV) and Parameter Usage Vocabularies (PUV). PDV vocabularies group parameters and do not necessarily have associated units. PUV vocabularies always have units (including dimensionless) and are used to plot the data or to insert in numerical models. The mappings among these terms will be available as web services ( See MMI ontology web services). The following table shows an initial MMI exercise to present relations among these two types of vocabularies:

Relationship among Parameter Usage Vocabularies (PUV) and
Parameter Discovery Vocabularies (PDV)

IOOS
(discovery)
GCMD
(discovery)
CF
(usage)
Bathymetry Bathymetry sea_floor_depth_below_geoid
sea_floor_depth_below_sea_level
sea_surface_height_above_geoid
Currents Ocean_Currents
Tidal_Currents
baroclinic_eastward_sea_water_velocity
baroclinic_northward_sea_water_velocity
barotropic_eastward_sea_water_velocity
barotropic_northward_sea_water_velocity
direction_of_sea_water_velocity
eastward_sea_water_velocity
northward_sea_water_velocity
sea_water_speed
sea_water_x_velocity
sea_water_y_velocity
upward_sea_water_velocity
Heat_flux Heat_Flux downward_heat_flux_in_sea_ice
northward_ocean_heat_transport_due_to_bolus_advection
northward_ocean_heat_transport_due_to_gyre
surface_downward_heat_flux_in_air
surface_upward_heat_flux_in_air
surface_upward_sensible_heat_flux
upward_sea_ice_basal_heat_flux
Ice_distribution Sea_Ice_Elevation
Sea_Ice_Motion
direction_of_sea_ice_velocity
downward_eastward_stress_at_sea_ice_base
sea_ice_area
sea_ice_draft
sea_ice_freeboard
sea_ice_speed
sea_ice_volume
upward_sea_ice_basal_heat_flux
Salinity Salinity sea_water_salinity
Sea_level Sea_Level_Rise
Sea_Surface_Height
Sea_Surface_Slope
global_average_sea_level_change
sea_floor_depth_below_sea_level
sea_surface_height_above_sea_level
Surface_waves
direction_of_swell_wave_velocity
direction_of_wind_wave_velocity
significant_height_of_swell_waves
significant_height_of_wind_waves
swell_wave_period
wind_wave_period
Temperature Water_Temperature sea_water_potential_temperature
sea_water_temperature