The Future We Want: a Learning Experience to Promote SDGs in Higher Education from the United Nations and University of Valencia
This article shares the strategy for mainstreaming the Sustainable Development Goals (SDGs) at the University of Valencia (UV), which, although limited in its scale, may compel other Higher Education Institutions to think in technological and social progress aligned with the 2030 Agenda. It explicates a process driven by the UV, on the occasion of the 75th anniversary of the United Nations (UN), and in collaboration with the Service for Geospatial, Information, and Telecommunications Technologies from the UN Support Base in Valencia (Spain) to prepare the online event: “The United Nations We Want”. It was the culmination of a collaborative project between students and faculties from differe…
Conversion of nadir, narrowband reflectance in red and near-infrared channels to hemispherical surface albedo
Abstract Measured nadir-viewed narrow-band reflectanees in red and near infrared channels simulating AVHRR Channels 1 and 2 are compared with measured integrated solar spectrum hemispherical albedos. Reflectanees and albedos were measured from an aircraft over four widely different vegetation surfaces in southeastern Tasmania (Australia). A linear function is used to simultaneously correct for narrow band to broad band conversion errors and to convert nadir viewed reflectances to hemispherical albedos. While the application of the conversion equation presented is limited to the vegetation types of the study, the equation is independent of vegetation type. Results indicate that the reflectan…
Flux retrieval optimization with a nonscanner along-track broadband radiometer
[1] The theoretical behavior of broadband flux retrieval is analyzed with the aid of a radiance field database. Several angular inversion models are developed for different viewing configurations, with special emphasis in a nonscanner along-track design concept. Results show that the performance of these angular models depends on the viewing zenith angle (VZA). When cloud cover is predominant within the observed scene, VZAs around 55° (shortwave) and 50° (longwave) minimize the error when deriving fluxes. These results might help in the design of future missions where the main idea is to obtain accurate instantaneous measurements of top of atmosphere reflected and emitted fluxes. Such measu…
The SMOS mediterranean ecosystem L-band characterisation experiment (MELBEX) over natural shrubs
10 páginas, 5 figuras, 7 tablas.
A flux retrieval error behavior with CERES/TRMM data
With the aid of CERES/TRMM (Clouds and the Earth's Radiant Energy System/Tropical Rainfall Measuring Mission) data, sampling problems that may impact the construction of anisotropic models have been investigated. We show the influence of the sun-orbit geometry, which causes a lack of measurements in forward and backward scattering directions at large viewing zenith angles, and how cloud properties retrieval algorithms as obtained from the Visible Infrared Scanner (VIRS) also affect sampling. We have also focused our attention on the dependency of the cloud cover retrieval algorithm with respect to the viewing zenith angle (VZA), showing that the shape of the cloud cover probability density …
Analysis of broadband surface BRDFs derived from TOA SW CERES measurements for surfaces classified by the IGBP land cover
Most studies on the reflectance properties of the Earth's surface are addressed estimating the bidirectional reflectance distribution function (BRDF) of high spatial resolution and high spectral resolution satellite measurements. This article assesses the development of broadband (BB) BRDFs from radiances corresponding to large footprints classified according to the International Geosphere-Biosphere Programme (IGBP) land-cover classification. Top-of-atmosphere (TOA) shortwave (SW) CERES (Clouds and the Earth's Radiant Energy System) measurements are employed to invert the bidirectional reflectance factor (BRF) Rahman–Pinty–Verstraete (RPV) model for regions identified with the same IGBP typ…
The SMAP and Copernicus Sentinel 1A/B microwave active-passive high resolution surface soil moisture product
Abstract Soil Moisture Active Passive (SMAP) mission of NASA was launched in January 2015. Currently, SMAP has an L-band radiometer and a defunct L-band radar with a rotating 6-m mesh reflector antenna. On July 7th, 2015, the SMAP radar malfunctioned and became inoperable. Consequently, the production of high-resolution active-passive soil moisture product got hampered, and only ~2.5 months (April 15th, 2015 to July 7th, 2015) of data remain available. Therefore, during the SMAP post-radar phase, many ways were examined to restart the high-resolution soil moisture product generation of the SMAP mission. One of the feasible approaches was to substitute the SMAP radar with other available SAR…
Retrievals of soil moisture and optical depth from CAROLS
International audience; We propose in this paper to evaluate a method to retrieve soil moisture (SM) and vegetation optical thickness, in areas of unknown roughness and unknown vegetation water content in view of operational applications, by using airborne Tb measurements acquired in South-West of France. Results are compared to in situ measurements, manual and automatic ones included in SMOSmania network, in the South-West of France.
An improved perspective in the representation of soil moisture: potential added value of SMOS disaggregated 1 km resolution product
Abstract. This study uses the synergy of multiresolution soil moisture (SM) satellite estimates from the Soil Moisture Ocean Salinity (SMOS) mission, a dense network of ground-based SM measurements, and a Soil Vegetation Atmosphere Transfer (SVAT) model, SURFEX (Externalized Surface) – module ISBA (Interactions between Soil-Biosphere-Atmosphere), to examine, i) the comparison and suitability of different operational SMOS SM products to provide realistic information on the water content of the soil as well as the added value of the newly released SMOS Level 4 3.0 all weather disaggregated ~ 1 km SM (SMOS_L4 3.0 ), and ii) its potential impact for improving uncertainty associated to SM initia…
L-Band radiative properties of vine vegetation at the MELBEX III SMOS Cal/Val Site
Radiative properties at 1.4 GHz of vine vegetation are investigated by measuring brightness temperatures with the ETH L-band Radiometer II (ELBARA II) operated on a tower at the Mediterranean Ecosystem L-band Characterisation Experiment III (MELBEX III) field site in Spain. To this aim, experiments with and without a reflecting foil placed under the vines were performed for the vegetation winter and summer states, respectively, to provide prevailingly information on vegetation transmissivities. The resulting parameters, which can be considered as "ground truth" for the MELBEX III vineyard, were retrieved from brightness temperature at horizontal and vertical polarization measured at observa…
Radiative Flux Estimation from a Broadband Radiometer Using Synthetic Angular Models in the EarthCARE Mission Framework. Part II: Evaluation
AbstractThe instantaneous top-of-atmosphere (TOA) radiance-to-flux conversion for the broadband radiometer (BBR) on board the Earth Clouds, Aerosols, and Radiation Explorer (EarthCARE) was assessed in Part I of this paper, by developing theoretical angular distribution models (ADMs) specifically designed for the instrument viewing configuration. This paper validates the BBR ADMs by comparing derived flux estimates with flux retrievals obtained from the Clouds and the Earth’s Radiant Energy System (CERES) Terra models. A CERES BBR-like database is employed in the assessment, which is an optimum dataset to validate the BBR algorithms and to determine the benefits of the multiangular conversio…
Characterization and Modelization of Surface Net Radiation through Neural Networks
Artificial neural networks have shown to be a powerful tool for system modeling in a wide range of applications. In this chapter, the focus is on neural network applications to obtain qualitative/quantitative relationships between meteorological and soil parameters and net radiation, the latter being a significant term of the surface energy balance equation. By using a Multilayer Perceptron model an artificial neural network based on the above mentioned parameters, net radiation was estimated over a vineyard crop. A comparison has been made between the estimates provided by the Multilayer Perceptron and a linear regression model that only uses solar incoming shortwave radiation as input par…
Modelling net radiation at surface using “in situ” netpyrradiometer measurements with artificial neural networks
The knowledge of net radiation at the surface is of fundamental importance because it defines the total amount of energy available for the physical and biological processes such as evapotranspiration, air and soil warming. It is measured with net radiometers, but, the radiometers are expensive sensors, difficult to handle, that require constant care and also involve periodic calibration. This paper presents a methodology based on neural networks in order to replace the use of net radiometers (expensive tools) by modeling the relationships between the net radiation and meteorological variables measured in meteorological stations. Two different data sets (acquired at different locations) have…
Synergetic exploitation of the Sentinel-2 missions for validating the Sentinel-3 ocean and land color instrument terrestrial chlorophyll index over a vineyard dominated Mediterranean environment
Continuity to the Medium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI) will be provided by the Ocean and Land Color Instrument (OLCI) on-board the Sentinel-3 missions. To ensure its utility in a wide range of scientific and operational applications, validation efforts are required. In the past, direct validation has been constrained by the need for costly airborne hyperspectral data acquisitions, due to the lack of freely available high spatial resolution imagery incorporating appropriate spectral bands. The Multispectral Instrument (MSI) on-board the Sentinel-2 missions now offers a promising alternative. We explored the synergetic use of MSI data for validat…
CAROLS: A New Airborne L-Band Radiometer for Ocean Surface and Land Observations
The "Cooperative Airborne Radiometer for Ocean and Land Studies" (CAROLS) L-Band radiometer was designed and built as a copy of the EMIRAD II radiometer constructed by the Technical University of Denmark team. It is a fully polarimetric and direct sampling correlation radiometer. It is installed on board a dedicated French ATR42 research aircraft, in conjunction with other airborne instruments (C-Band scatterometer--STORM, the GOLD-RTR GPS system, the infrared CIMEL radiometer and a visible wavelength camera). Following initial laboratory qualifications, three airborne campaigns involving 21 flights were carried out over South West France, the Valencia site and the Bay of Biscay (Atlantic O…