Downwelling Solar Irradiance as a Critical Parameter for In-Situ Measurements in the MERMAID Database
Abstract
The MERIS MAtchup In-situ Database (MERMAID) provides an essential tool for MERIS calibration and validation activities of ESA's Medium Resolution Imaging Spectrometer (MERIS). MERMAID comprises in-situ ρw from several measurement approaches, from fixed buoys and towers to floating instrumentation rigs. Analysis of the provided measurement protocols and the matchup data (in-situ and MERIS) has identified that sensor tilt seriously affects measurements of surface irradiance, and has consequent impacts on the accuracy of water reflectance, ρw, and matchup results. Activities intrinsic to the third MERIS reprocessing, such as the development of the vicarious adjustment gains computation, depend intrinsically on the MERMAID matchups and as such it is essential to ensure the quality of in-situ irradiance data. Results indicated the need to include in MERMAID 'homogenised' versions of datasets (consistent with MERIS assumptions), and stressed the need to investigate further the potential for tilt correction of Es.
- Publication:
-
ESA Living Planet Symposium
- Pub Date:
- December 2010
- Bibcode:
- 2010ESASP.686E.331B