Objective
The aim of the project is to achieve and maintain high quality standards in the spectral solar ultraviolet measurements performed in Europe, in preparation of the establishment of a European network of UV instruments. To ensure homogeneity and comparability between spectral UV measurements conducted by a continuously increasing variety and number of instruments, it is important to create close links among them and co-ordinate their operation. This can be achieved by establishing regional standards, which will be used to maintain the compatibility amongst the other instruments operating in the same region. The objective is to achieve, at the end of the project, a uniform group with the best possible geographical coverage and a large diversity of reliable instruments.
The main task of the project is to organise an intercomparison campaign, through which the performance of the
twenty participating instruments will be tested and evaluated. About half of the instruments that will take part
in the campaign belong to the contractors of SUSPEN, while the rest will be invited participants, either from
Europe or from other countries. The selection criteria will ensure large diversity of instruments, wide
geographical coverage and their potential to act in the future as regional standards in national or international
UV monitoring networks.
The campaign will comprise two phases: During the first phase, a blind intercomparison will be performed by
all instruments for at least two full days. During the instrument's set-up each participant will use its own means
to calibrate and operate its spectroradiometer, without exchanging data with other participants. The aim of this
first phase is to evaluate the performance of the instruments, as they would operate independently at their home
sites. This first phase is considered very important especially for the instruments that have taken part in the
previous campaigns, because it will provide proofs concerning the stability of these instruments, and the ability
of their operators to maintain their quality and calibration in time. The observational programme will include
continuous measurements from sunrise to sunset, to enable comparisons of spectra obtained at different zenith
angles and light intensities.
In the second phase all instruments will operate under a "looser" programme, allowing the participants to
perform measurements to investigate specific topics, such as the diurnal behaviour of the instruments,
comparisons of direct-sun spectra, differences in calibration standards, etc. Moreover, a preliminary evaluation
of the results from the blind-intercomparison will be performed to enable the participants to evaluate
independently the performance of their instruments. This will be very helpful, especially to the new participants,
which will have the opportunity to investigate the reasons of possible deviations from other instruments, and
to undertake, if necessary, the proper corrective actions. Weather permitting, every effort will be put into
obtaining measurements under different conditions (i.e. clear skies, overcast, partly cloudy, etc.), to examine
the response of each instrument under variable exposure conditions. The final stage of the project is the analysis of the data and the evaluation of the intercomparison results for
each instrument. The analysis of the measurements will be done according to the methodologies developed,
tested and adopted at the previous intercomparison campaigns, which assure the objectivity in the evaluation
results.
Topic(s)
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
54006 Thessaloniki
Greece