Quality Control Plan
The Quality Control plan of the NSF UV Monitoring Network consists of the following elements:
- Automatic Quality Checks (every few seconds)
All SUV systems sample ancillary data such as system temperatures at high frequency. If these measurements deviate from target values, remedial action is initiated.
- Daily Checks
Proper functioning of the system is checked daily by Research Associates, who also clean the instrument�s collectors. Measurements of irradiance and
wavelength standards that are internal to SUV spectroradiometers are automatically performed every day. Data are used to determine instrument stability or uncover instrument
- Weekly Data Processing and Quality Control
Raw data are processed weekly and preliminary data are posted here.
The procedure includes the following steps:
- Review of weekly briefs from the Research Associates
- Application of preliminary wavelength and irradiance calibration to raw data
- Generation of a quality report and review
- Posting of new data
- Initiation of remedial action if any of the above steps indicate problems
- Bi-weekly Calibrations
SUV spectroradiometers are calibrated bi-weekly by Research Associates with NIST-traceable Standards of Spectral Irradiance. Calibration data are reviewed during weekly data processing.
During the austral spring, a UV Bulletin is posted on the website.
- Comparison of GUV and SUV Data
Data from GUV multi-channel radiometers are compared with data from collocated SUV spectroradiometers several times
during the year.
- Annual Activities
The following activities are conducted annually:
- Training of Research Associates at Biospherical Instruments
- Visits of network sites by BSI personnel. Activities include:
- Season-end calibrations and comparison of on-site standards with traveling standards
- Inspection, maintenance and repair of instruments
- Upgrades of instruments
- Season-start calibrations.
- Preparation of final "Version 0" data
Following review of site visit data, all solar data recorded between two annual site visits are reprocessed and published.
- Review of all calibration scans performed during the last year
- Application of the final wavelength correction to solar data.
- Calculation of calibration factors for ancillary sensors (e.g. PSP, TUVR).
- Quality control of final data with database tools. This involves a comparison of measured data with target values, comparison of new data with data from previous years and external data (e.g. NASA/TOMS).
- Dissemination of final "Version 0" data
- Documentation of Quality Control results in Network Operations Reports
- Publication of final data on CD-ROMs
- Comparison of Standards of Spectral Irradiance
Standards of Spectral Irradiance used in the NSF UV Monitoring Network are traceable to the NIST irradiance scale. Calibration lamps are sent out for recalibration at
regular intervals. In addition, calibration lamps are compared with standards of NIST/NOAA�s Central UV Calibration Facility
- Participation in Intercomparisons
Spectroradiometers of the NSF UV Monitoring Network regularly participate in national and international intercomparisons. Results have been published in peer-reviewed
journals and have been used to improve instrumentation, measurement protocols, and data analysis procedures.
- Comparison with Radiative Transfer Models
Spectral data of the NSF UV Monitoring Network are compared in regular intervals with results of radiative transfer models.
- Publication of Results in Scientific Journals
Data of the NSF UV Monitoring Network are regularly published in scientific journals either by BSI or researchers not associated with BSI.
- Re-evaluation of Network Data
Version 0 data of the UVSIMN exhibits some known and well-documented systematic errors. To address these problems, a new data version,
named "Version 2" is currently being produced.