Station Lists Explained

For metObs v2, oceanObs v2 and lightningdata v2 the station list represents both present and historical data about a station. This means that there can be more than one occurance of a station in the station list. This is usually due to small changes in the stations metadata (i.e., its location or height). 

Each occurance of the same station has a validity period that applies to that exact combination of station metadata. 

The validity period of each station occurance is denoted by the validFrom and validTo fields with validTo = null meaning no end time (forever).

The Kitsissut barometer height was determined to be 15 at 2019-01-15 13:34:47.074, resulting in two station occurances - one denoting the stations data before 2019-01-15 13:34:47.074 and one after this point in time. Each occurance with its own distinct combination of station metadata.

The Frederikshavn station was decommissioned at 1991-11-14 00:00:00.000, resulting in two station occurances - one denoting the period in which the station was active and can be expected to have observations and one denoting the period after the station was decommissioned. 

See also: https://en.wikipedia.org/wiki/Slowly_changing_dimension#Type_2:_add_new_row (external site)

The fields operationFrom and operationTo indicates the period in which a given station was active and registering meassurements. This information remains unchanged even for the station occurances/rows where the station is inactive due to e.g. decommissioning. See example below.

When using a datetime parameter in a station query, the datetime parameter applies to the operational period of a given station. If we look at  the example above (example 3) this means that if you use the datetime parameter to query results for a period between 1970-01-14 and 1991-11-14, the query will return all station occurances for that given period including the occurances in which the station is inactive. 

In order to avoid receiving station results where a station is inactive you need to include the status parameter which indicates whether a station is active or inactive at a specific point in time.

Below you'll see som examples on using the datetime and status parameters in a station specific query:

You can read more on how to build your query by reading our Query Primer.