Bio-Optical Sensors on Argo Floats

The general objective of the IOCCG BIO-Argo working group is to elaborate recommendations for establishing a framework for the future development of a cost-effective, bio-optical float network corresponding to the needs and expectations of the scientific community. In this context, our recommendations will necessarily be broad; they range from the identification of key bio-optical measurements to be implemented on floats, to the real-time management of the data flux resulting from the deployment of a "fleet of floats". Each chapter of this report is dedicated to an essential brick leading towards the goal of implementing a bio-optical profiling float network. The following topics are discussed in the Chapters listed below: - Chapter 2 reviews the scientific objectives that could be tackled through the development of such networks, by allowing some of the gaps in the present spatio-temporal resolution of bio-optical variables to be progressively filled. - Chapter 3 identifies the optical and bio-optical properties that are now amenable to remote and autonomous measurement through the use of optical sensors mounted on floats. - Chapter 4 addresses the question of sensor requirements, in particular with respect to measurements performed from floats. - Chapter 5 proposes and argues for the development of dedicated float missions corresponding to specific scientific objectives and relying on specific optical sensor suites, as well as on specific modes of float operation. - Chapter 6 identifies technological issues that need to be addressed for the various bio-optical float missions to become even more cost-effective. - Chapter 7 covers all aspects of data treatment ranging from the development of various quality control procedures (from real-time to delayed mode) to the architecture required for favoring easy access to data. - Chapter 8 reviews the necessary steps and experience required before the operational implementation of different types of float networks can become a reality.JRC.H.5-Land Resources Managemen

Ocean Colour Calibration and Validation: The JRC contribution to Copernicus

Copernicus Sentinel-3 missions, including the ongoing Sentinel-3A and -3B and the future Sentinel-3C and -3D, offer an unprecedented opportunity for long-term ocean colour observations to support global environmental and climate investigations. Nevertheless, any ocean colour mission incorporates calibration and validation activities essential for the indirect calibration of the space sensor and the validation of data products. These calibration and validation activities are largely centered on the production of highly accurate in situ reference measurements relying on state of the art measurement methods and instrumentation. Since the start of the operational ocean colour missions in 1997, the JRC sustained the required calibration and validation activities by developing unique expertise and setting up specific measurement programs and infrastructures. This expertise, measurement programs and infrastructures, currently support the Copernicus ocean colour calibration and validation tasks through the delivery and exploitation of in situ reference data essential for the quality control of satellite data products. This Technical Report aims at providing: i. a general introduction to the ocean colour paradigm; ii. an extended synopsis of requirements and strategies for satellite ocean colour missions with a detailed focus on the JRC experimental activities carried out during the last decades; and finally iii. a discussion supporting the need for a sustained support of the JRC laboratory and field measurement programs assisting the production and exploitation of in situ reference data for the validation of Sentinel-3 ocean colour products. The Report, mostly through section 2, should naturally satisfy readers interested in appraising the specific JRC activities performed to support ocean colour calibration and validation. The same Report through sections 1 and 3, should also satisfy the need for more essential information supporting the need for sustaining the JRC ocean colour validation activities currently embedded in the Copernicus Earth Observation program of major relevance for global marine and climate investigations.JRC.D.2-Water and Marine Resource

Statistical Assessment of Radiometric Measurements from Autonomous Systems

In situ autonomous systems are commonly used for the collection of measurements for the vicarious calibration of satellite data and the successive validation of derived products. However, the use of autonomous systems creates the need of assessing the quality of the large volume of collected data. Within the framework of ocean color activities, this work investigates the consistency of spectral normalized water leaving radiances taken from an above-water autonomous system installed on an oceanographic tower. The study has shown the need of addressing the problem under two different levels of inference. The first level, so called self-consistency, has demonstrated the capability of identifying spectra with a low statistical representatitivity within the data set itself. The second level, so called relative-consistency, has provided the possibility of evaluating wheatear a spectrum is consistent relatively to a reference set of quality assured data.JRC.H.5-Rural, water and ecosystem resource