services provide unified missing values
unify missing values:
-999.0 for float values
-1 for categorial values (like HTAP region)
GEOPEAS:
(see views.py of related service)
- climatic_zones: default_value=0.
- ecoregions: default_value=-1.
- htap_regions_tier1: default_value=-1
- landcover: default_value=0.
- major_roads: null
- nox_emissions: default_value=-999.
- population_density: (see population_number)
- population_number: default_value=-999.
- stable_nightlights: default_value=-99.
- topography_srtm: default_value=-9999.
GEOPEAS also provides out-of-bound values (f. ex. -888);
this is illustrated in
https://toar-data.fz-juelich.de/api/v2/stationmeta/id/7
GEOPEAS should provide the unified missing values.