Joint research activity 3:
Real-time data acquisition of advanced aerosol parametersObjectives and expected impact
The objective is to provide users with real time data from aerosol measurement instruments. Today’s real time data systems are commonly used only for O3, CO, SO2, NOX, and PM10/2.5. To include more advanced aerosol measurements an extensive development of new software is essential. EUSAAR will make use of state of the art IT communication techniques to bring aerosol data from the research sites to the Institutes’ offices and laboratory tables of Europe. The developments undertaken within JRA3 will, therefore, markedly improve the exchange of information through standard procedures of communication.
Description of work
To ensure fast and reliable data transfer from sensors to the user, several steps have to be considered: the sensor, data logging, data transfer, data storage, quality control, data processing, data distribution and data presentation. Existing installations may range from only local data collection to complete systems as described above although most of them are likely to fall into the former category. A modern system should be based on distributed data collection and centralised data storage and data presentation. This will be achieved by logging data locally and transferring the data from the data logger to the central database via GSM, GPRS, ground based modem or the Internet. Data integrity will be checked on arrival by statistical procedures and automatic data controls before presentation on the Internet. The users will access the data in the database through a web application or by automatic data transfers. The web application will include statistical and graphical tools for processing the data in a unified way.
Due to the variety of advanced aerosol instruments and data logging/ transfer/ data visualisation systems existing, it is important to define the user requirements before specifying a unified system. To develop the system, three well-equipped test sites (PDD, MHD and CBW) have been selected because they cover most types of instrumentation, data processing capability, data transmission and data visualisation know-how. This leads to the following tasks:
Task 1. Organisation of a workshop early in the project to get input from users.
Task 2. Specification of a unified data collection, data transfer and data presentation system based on the information gathered at a workshop combined with literature studies.
Task 3. Evaluation of costs related to equipment and operation, e.g. data transfer using GSM modems, which is expensive in some countries.
Task 4. Development of a common database and web tools, which will be hosted at NILU. This includes the development of a simple automatic data checking procedure to prevent invalid data, such as values outside limits, from being displayed on the Internet, and web based statistical and graphical tools to enable the user to analyse the data. This should be a parallel activity to N5. Also, necessary hardware, e.g. data loggers will be developed for sites where these are lacking.
Task 5. Implementation of the data acquisition, transmission and display system will be carried out at the three test sites and run for 4 months in a full-scale test. During the test, selected users will evaluate the systems using a system evaluation procedure. The user evaluations will be used to modify the specifications and systems. A manual quality control tool will be developed to enable the user to flag invalid data. Based on user evaluation, the automatic quality control/data checking tools will be developed further.
Task 6: A data exchange module will be specified and developed for exchange of data with internal and external users, e.g. EUSAAR, EMEP, Meteorological offices, etc. The exchange module will cover both manual and automatic (scheduled) data transfers. The data exchange modules will be run for 3 months as a full-scale test.
