Folks:
we have a product type (lightning detections) that has three data variables
where there is a relationship that must be captured in the NetCDF data set.
The 3 data variables are (1) flash_energy, (2) group energy), and (3)
event_energy.
A flash_energy is associated with one or more group_energy elements. A
group_energy is associated with one or more event_energy elements.
To support this, have identified 2 new standard attributes, "association" and
"associations", and added a concept of an "association variable".
float flash_energy (number_of_flashes);
:associations = “flash_energy flash_group_association group_energy”;
float group_energy (number_of_groups);
:associations = “flash_energy flash_group_association group_energy,
group_energy group_event_association event_energy";
float event_energy (number_of_events);
:associations = “group_energy group_event_association event_energy”;
long flash_group_association (number_of_groups);
:association = “flash_energy group_energy”;
long group_event_association (number_of_events);
:association = “group_energy event_energy”;
Flash, group, and event association attributes and variables notes
· There is one association variable to capture the associations between
individual flashes and groups, and another association variable to capture the
associations between individual groups and events.
· The group_energy data variable specifies two associations as it is a
destination data variable for the flash to group association and a source data
variable for the group to event association.
· The extent of the association variables’ dimensions is the same as the
association’s destination data variable.
*** Note that this convention only makes sense when the affected data variables
have a single dimension (e.g. points).
