Quality flags are constructed on a philosophy of two qualifiers. The first describes the origin of the data and the second the quality.
Possible origins of data are:
+ Original: This entails the data value is the original value. It has not been amended by DELFT-FEWS
+ Completed: This entails the original value was missing and was replaced by a non-missing value.
+ Corrected: This entails the original value was replaced with another non-missing value.
Possible qualifiers are:
+ Reliable: Data is reliable and valid
+ Doubtful: The validity of the data value is uncertain
+ Unreliable: The data value is unreliable and cannot be used.
Following this specification, the table below gives an overview of quality flag enumerations
Table 1 Enumeration of quality flags
Enumeration | Description |
0 | Original/Reliable |
1 | Corrected/Reliable |
2 | Completed/Reliable |
3 | Original/Doubtful |
4 | Corrected/Doubtful |
5 | Completed/Doubtful |
6 | Original/Unreliable |
7 | Corrected/Unreliable |
8 | Completed/Unreliable |
9 | Missing value in originally observed series. Note this is a special form of both Original/Unreliable and Original/Reliable. |
Notes:
- No difference is made between historic and forecast data. This is not considered a quality flag. The data model of Delft-FEWS is constructed such that this difference is inherent to the time series type definition.