Quality flags are constructed on a philosophy of two qualifiers. The first described the origin Time series flags describe the origin and the quality of the data and the second the quality.
Possible origins of data are:
1. Original- Original: This entails the data value is the original value. It has not been amended by Delft-FEWS
2. Completed- Completed: This entails the original value was missing and was replaced by a non-missing value.
3. Corrected- Corrected: This entails the original value was replaced with another non-missing value.
Possible qualifiers Qualities are:
4. Reliable- Reliable: Data is reliable and valid
5. Doubtful- Doubtful: The validity of the data value is uncertain
6. Unreliable- Unreliable: The data value is unreliable and cannot be used.
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Enumeration | Description |
0 | Original/Reliable
The data value is the original value retrieved from an external source and it successfully passes all validation criteria set. |
1 | Corrected/Reliable
The original value was removed and corrected. Correction may be through interpolation or manual editing. |
2 | Completed/Reliable
Original value was missing. Value has been filled in through interpolation, transformation (e.g. stage discharge) or a model. |
3 | Original/Doubtful
Observed value retrieved from external data source. Value is valid, but marked as suspect due to soft validation limits being exceeded. |
4 | Corrected/Doubtful
The original value was removed and corrected. However, the corrected value is doubtful due to validation limits. |
5 | Completed/Doubtful
Original value was missing. Value has been filled in as above, but resulting value is doubtful due to limits in transformation/interpolation or input value used for transformation being doubtful. |
6 | Missing/Unreliable
Observed value retrieved from external data source. Value is invalid due to validation limits set. Value is removed |
7 | Corrected/Unreliable
The original value was removed and corrected. However, corrected value is unreliable and is removed. |
8 | Completed/Unreliable
Original value was missing. Value has been filled in as above, but resulting value is unreliable and is removed. |
9 | Missing value in originally observed series. Note this is a special form of both Original/Unreliable and Original/Reliable.. Missing values are automatically unreliable |
Next to the flag it is also possible to get or set information why the flag is as it is through the so-called flagSource. Since version 2012.01 FEWS stores not only the quality flags, but also the source of the flag, the so-called flagSource. So the user is able to see why a certain value is validated as unreliable, eg. due to exceeding of the hard max.
The list of flagSources is:
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