Values

The main work of DB-ALLe is to store and access measured values. A measured value is described by:

1. The local B table descriptor, which describes the nature of the variable, such as what it measures and the units used for measuring.
2. The measured value.
3. pseudoana information about what generated the value.
4. The vertical coordinates in space, as a description of the level layer.
5. The time range of the measurement.
6. The type of report (for example: measured value, forecast...).

You can find a list of all current B table descriptors in C.1.

The type of report implicitly defines a priority of the measured value over other equivalent values. This can be used to select a ``best value'' from a specific set of coordinates, where for example, values measured by synoptic stations are preferred over values measured by a satellite, which in turn is preferred over a value computed by a forecast model.

Priorities associated to the report type can be customized when creating the database (see 3.4.3).

Every measured value in DB-ALLe can be assigned any number of extra attributes, which can be used, for example, for quality control.

DB-ALLe also supports storing values about a station (such as station height, or station name). These are called pseudoana values and are handled just like values, with the exception that vertical coordinates, datetime and time range have no meanings and are forced to default values.

Pseudoana values, just like normal values in DB-ALLe, can have attributes and any B code. It is possible to have pseudoana values for a station on different networks, although this is rarely needed and the ana network is normally used for pseudoana values.

See section for examples on how to work with values.