-
Notifications
You must be signed in to change notification settings - Fork 22
Observations, observed variables and sampling procedures
- observation = observed variable x geometry x procedure
- observed variable = domain x subdomain(s) x variable
- procedure = sampling x processing x reporting
- sampling = size x pressure x temperature x humidity
- processing = sample treatment x method x method details x instrument x operator
- method details = wave length(s) x free text
- operator = an individual involved in making the observation
Hence, to describe an observation, we must include many aspects. The various metadata models (ISO 19156, WMDS, etc) then re-group / organize these aspects in various feature types, thereby also creating dependencies and hierarchy.
- domain = {atmosphere, terrestrial, ocean, outer space}
- sub-domain(s) involves concepts like matrix and further grouping of variables, "matrix" refers to concepts like "gas", "particle phase", "total atmospheric deposition" etc.
- variable = biogeochemical species or physical quantity
http://codes.wmo.int/wmdr/Geometry
discussion required
Option 1: One code table for particle sizes, from which a size range can be built up by specifying minimum and maximum values.
| notation | name | description |
|---|---|---|
| 1 | 0.001 | Particles with diameter 0.001 µm |
| 2 | 0.1 | Particles with diameter 0.1 µm |
| 3 | 1 | Particles with diameter 1 µm |
| 4 | 2.5 | Particles with diameter 2.5 µm |
| 5 | 10 | Particles with diameter 10 µm |
| na | NA |
Option 2: One code table for size ranges
| notation | name | description |
|---|---|---|
| 1 | PM0.001 | Particles with diameter 0.001 µm |
| 2 | nucleation | PM0.001 - PM0.1, particles with diameter from 0.001 to 0.1 µm (nucleation mode) |
| 3 | PM0.1 | Particles with diameter under 1 µm |
| 4 | accumulation | PM0.1 - PM1, particles with diameter from 0.1 to 1 µm (accumulation mode) |
| 5 | fine | PM1, particles with diameter under 1 µm (fine mode) |
| 6 | coarse | Particles with diameter greater than 1 µm (coarse mode) |
| 7 | PM2.5 | Particles with diameter under 2.5 µm |
| 8 | PM2.5 - PM10 | Particles with diameter from 2.5 to 10 µm |
| 9 | PM10 | Particles with diameter under 10 µm |
| 10 | total | No distinction in particle size |
It needs to be determined, how many different size ranges are actually needed in practical use, and if a more flexible approach (option 1) is preferable.
discussion required
For an approach with a controlled variable list, a code table like the following could be used.
| notation | name | description |
|---|---|---|
| 1 | ambient | Relative humidity at ambient conditions |
| 2 | dry | Reduced relative humidity, less than 40 % |
| 3 | ... |
Alternatively, the input of values in form of a "free text" to specify specify a range from minimum to maximum value (in decimal numbers) instead of using a code list is possible.
discussion required
discussion required
discussion required
discussion required
To illustrate this, it makes sense to look at an examplary station report in the OSCAR/Surface application (Payerne), which contains aerosol observations.
Observations/measurments
Atmosphere > Aerosol
Composition > Inorganic anions > Chloride (Cl-) [Geometry: Point, Size range: PM10]
-
Variable: Chloride (Cl-)
Geometry: Point
Size range: PM10
Programs / network affiliations: ...\ -
Deployment
Source of observation:...
...-
Sampling
- Relative humidity: ...
- Temperature: ...
- Pressure: ...
- Instrument characteristics
- Data generations
-
Sampling