Measurements

The measurement databases consist of:

• Meteorological data
• Air quality data
• Meta data (station description, instrument description, etc)

Measurement time series
The data in the database are organised in data series (measurement time series). 

Meteorological Data
All meteorological data are stored as time series. Climatological statistics can be achieved by the use of the statistical packages Windrose, Stabfreq and Metfreq. (See Data statistics). In this way joint frequency distribution of wind speed, wind direction and atmospheric stability can be calculated.

Air Quality data
Air quality data can be imported to the AirQUIS database by:

• A manual data entering application.
• An on line monitoring system.
• A module for online data acquisition and quality control.

Data may be automatically transferred to the AirQUIS database. To collect air quality and meteorological data from various measurement stations a robust and stable communication network is required to obtain high frequency of operation. NILU has developed a user friendly Automatic Data Acquisition System (ADACS), which is an integrated part of the AirQUIS system. (See ADACS )

Meta database

The data series are identified by a set of properties that describes the values. The averaging period is set by the data collecting system. The necessary properties to identify data series in the measurement database are given in the table:

Data statistics