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Figure J 1. A BSRN station and the WRMC.
Annex J BSRN Data Management
This annex contains an outline of the BSRN data management. A comprehensive description is given
in (Gilgen et al. 1995).
The relationships between the BSRN stations and the WRMC are shown in Figure J1 which is a simplified
version of Figure 2.1 in (Gilgen et al. 1995). The observations are made at the BSRN stations. The
data are accumulated during a month and their quality is checked by the station scientist. The monthly
data sets are then forwarded to the WRMC using the BSRN station-to-archive file format in ASCII code.
Data transfer is made preferably by electronic means. The BSRN stations keep the log and the original
readings for the duration of the BSRN project to allow anytime for a re-evaluation.
A monthly data set consists of station log data and of atmospheric data (including the radiation data)
formatted as prescribed in (Gilgen et al. 1995) and (Hegner et al. 1996). The station log data describe
the station, the radiation instruments and the measurements. They are semantically much richer than
the atmospheric data and thus are often afflicted with omissions and/or contradictions. Consequently,
rules asserting the consistency of the station log data have been incorporated in the definition of the
station-to-archive file format, e.g., "an instrument is assigned to every radiative flux". The station log
data are written in the first part of the station-to-archive file. The radiation and the other atm ospheric
data are written in the second part of the station-to-archive file.
The WRMC data manager supports the BSRN station scientists when they start to prepare the monthly
data sets: sample station-to-archive files and a format check program are available. It is recommended
to apply the format check program before a station-to-archive file is forwarded to the WRMC. The format
check program however does not perform consistency checks for the following reason. The consistency
checks not only validate the data across the different parts in a site-to-archive file using the rules which
are part of the format definition, but they also compare the station log data with the data already stored
in the database. Thus, the consistency of a station-to-archive file is checked at the WRMC. If a station-to-
archive file is found to be consistent, the data are inserted in the BSRN database. If a file is found
to be inconsistent, a detailed consistency report is forwarded to the station concerned. The BSRN
station scientist then prepares a consistent monthly batch of data.
On the one hand, the formalization of the descriptions of a station and of the measurements needs
some effort when the monthly data sets are prepared for shipping. On the other hand, it is a prerequisite
for the systematic treatment of station log data in a database. Only accurate and consistent station
log data can be integrated with the radiation data and the other atmospheric data in the BSRN database.
The consistency checks assert that the data in the BSRN database do not violate the integrity constraints
which are part of the database definition. The BSRN database is managed by the WRMC.
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