Calibration and Validation of Thermal Infrared Remote Sensing Sensors and Land/Sea Surface Temperature algorithms over the Iberian Peninsula

La Temperatura de la Superficie Terrestre (TST) y la Temperatura de la Superficie del Mar (TSM) son parámetros clave en los procesos físicos de intercambio de energía entre la superficie y la atmósfera. La TST/TSM están directamente relacionadas con el espectro Infrarrojo Térmico (TIR) que constituye la principal fuente de emisión de radiación de la superficie terrestre. El control de los datos térmicos se puede realizar con la Calibración Vicarea (VC) para, de esta forma, garantizar la calidad de los datos una vez el sensor a bordo de satélite está en órbita. Normalmente, la validación directa de los algoritmos de TST y la VC del espectro térmico se realiza con datos in-situ en tierra, mientras que la TSM se puede validar con datos de boyas. En el marco del proyecto CEOS-Spain, la Unidad de Cambio Global (UCG) ha instalado seis estaciones fijas y automáticas en la península Ibérica, en tres sitios de validación (Barrax, Doñana y Cabo de gata) los cuales obtienen datos para la realización de las actividades de calibración y validación (cal/val) de sensores con una baja y media resolución espacial. La validación de la TSM ha sido realizada con datos de boyas disponibles en la página web de Puertos del Estado. Antes de la realización de la cal/val, un estudio completo de los sitios de validación ha sido realizado para obtener la máxima precisión de las medidas realizadas por las estaciones. Las fuentes de error más comunes asociadas a las medidas in-situ de la TST son, entre otras: la homogeneidad del terreno, la emisividad y la radiación descendente. Conociendo cada error y su contribución a la medida de la TST, se ha podido establecer la precisión de nuestras medidas in-situ. Para nuestras estaciones, se ha obtenido un error por debajo de 1 K. Teniendo en cuenta los errores de la medidas in-situ, la VC ha sido realizada la los sensores TIR sensor (TIRS), Enhanced Thematic Mapper Plus (ETM+) y MODIS, mostrando todos ellos valores precisos de las bandas del térmico. La validación de los algoritmos de TST también se ha realizado de forma directa e indirecta (con datos de sensor a bordo de avión). Los resultados de validación muestran valore por debajo de 2 K y, en los mejores casos y en las condiciones más favorables, valores por debajo de 1 K. Los algoritmos de estimación de la TSM (de tipo split-window) también han obtenido una precisión por debajo de 0.8 K y, en los mejores casos (sin radiación solar y con altas velocidades del viento), valores por debajo de 0.5 K. Finalmente, dos algoritmos de la TST (para TIRS y MODIS) y uno de la TSM (para MODIS) han sido propuestos para su inclusión en la cadena de procesado gestionada por la UCG.Land Surface Temperature (LST) and Sea Surface Temperature (SST) are a key parameters in physical processes of surface energy at local and global scales. LST/SST are directly related to Thermal Infrared (TIR) spectra, which constitute the main source of Earth emission. Control of satellite TIR data can be performed through Vicarious Calibration (VC), which is the more common way to guaranty data quality once sensor is on orbit. Usually, direct validation of LST algorithms and VC of TIR data is performed through in-situ measurements of LST while SST is controlled through anchor buoys or ship transect data. In the framework of CEOS-SPAIN project, Global Unit Change (GCU) group has installed six fixed and automatic stations in three test sites over the Iberian Peninsula (Barrax, Doñana and Cabo de Gata), which provides suitable data for calibration and validation (cal/val) activities of middle and low spatial resolution Earth Observation Sensors (EOS). Validation of SST has been performed with buoys web data available in the database of Puertos del Estado webpage. Before sensors cal/val, complete suitability study of land test sites was performed in order to obtain the maximal precision given by our fixed stations (in Kelvin). Uncertainties sources linked to in-situ LST retrievals were analyzed such as area inhomogeneity, emissivity or down-welling radiance among others. Finally, with each uncertainty source contribution it was possible to establish the precision of our in-situ measurements regarding the sensor’s spatial resolution. For our test sites, LST precision was set below 1 K. Keeping in mind the values of in-situ LST precision, VC was performed on Landsat TIR sensor (TIRS) and Enhanced Thematic Mapper Plus (ETM+) as well as Terra/Aqua MODerate-resolution Imaging Spectroradiometer (MODIS), showing no displacement in raw TIR data. Test of LST algorithms was also performed with direct and indirect (through airborne sensor data) validations. Results showed Root Mean Square Errors (RMSE) in LST estimations below 2 K and, in the best cases (with the most favorable external conditions), values of 1 K. SST algorithms (Split-Window type) demonstrated precisions below 0.8 K and, in the best case (no solar radiation and high wind velocity), values of 0.5 K. Finally, two LST algorithms (for TIRS and MODIS) and one SST algorithm (MODIS) have been proposed for its inclusion in the sensor images process chain managed by the GCU group

Patienternas inställning till att vårdas på en flerbäddssal med patienter av det motsatta könet

Det finns inte mycket forskning kring hur patienternas inställning är till att vårdas på en flerbäddssal med patienter av det motsatta könet och vad det har för betydelse i sjuksköterskans planering av var patienterna ska placeras för sin vård. Syftet med denna studie var att undersöka patienternas inställning till att vårdas på en flerbäddssal med patienter av det motsatta könet. Metoden som användes var en kvantitativ ansats med deskriptiv statistik. Ett eget utvecklat frågeformulär framställdes och delades ut av sjuksköterskorna på akutvårdsavdelningen till patienterna som ville delta i studien. Resultatet var att patienterna, oavsett ålder, ställde sig positiva till att vårdas på en flerbäddssal med patienter av det motsatta könet och upp till tre medpatienter på salen. Det fanns enstaka patienter som ställde sig helt negativa och ville ligga på ett enkelrum och detta ligger på sjuksköterskans ansvar att vara lyhörd till. Det fanns även en patientgrupp som var födda mellan åren 1970-1995 som uttryckte en oro över att kroppsligt blottas men kunde åtgärdas genom god användning av draperierna på salen. Eftersom denna studie hade en tidsbegränsning och endast hade 46 deltagande patienter är det svårt att generalisera resultatet och mer forskning krävs inom ramen för detta ämne.There is not much research on how patients' attitude is to be cared for in a multiple bedroom with patients of the opposite sex and how its significanct in the nurse scheduling of were to place patients in their caretime. The purpose of this study was to examine patients' attitudes to be cared for in a multiple bedroom with patients of the opposite sex. The method that was used was a quantitative approach with descriptive statistics. An own developed questionnaire was prepared and distributed by the nurses in the emergency department for patients who wanted to participate in the study. The result was that patients, regardless of age, were in favor of being cared for in a multiple bedroom with patients of the opposite sex and up to three other patients in the ward. There were some patients who stood completely negative and wanted to sleep in a single room and this is the nurse's responsibility to be sensitive for. There was also a group of patients who were born between 1970-1995 who expressed a concern that physically be exposed but could be addressed through good use of curtains in the room. Because this study had a time limit and only had 46 participating patients, it is difficult to generalize the results, and more research is required in connection with this topic

Influence of component temperature derivation from dual angle thermal infrared observations on TSEB flux estimates over an irrigated vineyard

A two-source model for deriving surface energy fluxes and their soil and canopy components was evaluated using multi-angle airborne observations. In the original formulation (TSEB1), a single temperature observation, Priestley–Taylor parameterization and the vegetation fraction are used to derive the component fluxes. When temperature observations are made from different angles, soil and canopy temperatures can be extracted directly. Two dual angle model versions are compared versus TSEB1: one incorporating the Priestley–Taylor parameterization (TSEB2I) and one using the component temperatures directly (TSEB2D), for which data from airborne campaigns over an agricultural area in Spain are used. Validation of TSEB1 versus ground measurements showed RMSD values of 28 and 10 Wm−2 for sensible and latent heat fluxes, respectively. Reasonable agreement between TSEB1 and TSEB2I was found, but a rather low correlation between TSEB1 and TSEB2D was observed. The TSEB2D estimates appear to be more realistic under the given conditions

Irrigation management though the assimilation of multiple remote sensing data into an energy-water-crop model

International audienceThe agricultural sector is the biggest and least efficient water user, accounting for around 80% of total water use in South Europe, which will be further impacted by climate change in the incoming years. Precision agriculture tools are then needed to increase water use efficiency.</p><p>Here, the proposed system couples together remotely sensed land surface temperature (LST), leaf area index (LAI) and ground soil moisture data (SM) with a pixel wise crop-water-energy balances model, for improving irrigation management. The SAFY (Simple Algorithm for Yield) crop model has been fully coupled with the energy water balance FEST-EWB model, exchanging in a double direction the LAI evolution in time from SAFY, which is used by FEST-EWB for evapotranspiration computation, while FEST-EWB provides soil moisture (SM) and LST to SAFY model for constraining crop growth.</p><p>A data assimilation framework, based on the Ensemble Kalman filter approach, is implemented to reduce the requirements for parameters calibration, either for soil assimilating satellite LST and for crop growth using LAI. This framework allows overcoming the issues related to crop exposure to shocks due extreme events non-reproducible by the model alone, as well as nutrient lack, crops hybrids or precise amount of irrigation water.</p><p>The FEST-EWB-SAFY model has been applied in two Irrigation Consortia in the North and South of Italy which differ for climate and agricultural practices, using data from Sentinel2, Landsat 7 and 8 satellites. The model has then been validated in specific fields where ground measurements of evapotranspiration, soil moisture and crop yields are available.</p><p>Overall, the results suggested that the under-calibrated model estimates of LST, LAI, SM and yield are enhanced through the assimilation of satellite data, suggesting the potential for improving irrigation management at both field and Irrigation Consortium scales.</p&gt

Modeling of Water Distribution under Center Pivot Irrigation Technique

Aiming to quantify the impacts of the center pivot irrigation technique on soil moisture dynamics and to improve irrigation crop water needs, a mathematical model was developed to estimate the water distribution pattern of a center pivot. The model is based on the ballistic theory modeling of a single sprinkler radial curve that simulates the trajectories of the droplets discharged by the sprinkler's nozzle. Subsequently, a water distribution pattern of a sprinkler irrigation technique (and ultimately center pivot) can be accurately estimated. This paper describes the theoretical and mathematical approaches of the developed model and its application in the case study, which was Las Tiesas farm in the area of Barrax, Spain, because the model was expanded to take into account the presence of not only one center pivot but multiple ones. In the case study, several center pivots with different characteristics in terms of size and hourly irrigation rates are present. The model correctly estimates the water distribution as it takes into account the different spatial (different sizes of pixels) and temporal basis (hourly and daily basis) and correctly estimates the water distribution when compared with satellite data. The results are given by the model, which is strictly done in the following order: simulating droplets trajectories, water distribution radial curve of single sprinkler, overlapped sprinklers patterns, and center pivots water distribution radial curve and patterns. The mathematical model gives the water distribution pattern under a center pivot irrigation system on a daily and hourly basis. The model can be adjusted to give the results not only for one center pivot but for two or more as desired

A fully coupled crop-water-energy balance model based on satellite data for maize and tomato crops yield estimates: The FEST-EWB-SAFY model

Agricultural crop management requires extensive and comprehensive tools that allow for a full knowledge of the crops' status and growth dynamic. This study aims at estimating crop yield for maize and tomato crops over large areas at field scale. For this purpose, we developed a fully coupled model based on a parameter-saving crop growth model (Simple Algorithm For Yield estimates (SAFY)) with a water-energy balance model (Flash-flood Event-based Spatially-distributed rainfall-runoff Transformation-Energy Water Balance model (FEST-EWB)) with a double exchange of leaf area index (LAI) and soil moisture (SM) information. Both models are driven by remote sensing data and are calibrated independently from in situ measurements. Satellite LAI data are used to calibrate the crop growth model parameters, while the energy-water balance parameters are calibrated against satellite land surface temperature (LST) data. Multiple satellite data are used either at high spatial resolution (Sentinel 2 and LANDSAT 7 and 8) and at low-resolution (MODIS). Two Italian case studies are selected to test the model accuracy: the Chiese Irrigation Consortium (Northern Italy), mainly devoted to maize crop cultivation, and the Capitanata Irrigation Consortium (Southern Italy), where tomatoes are largely diffused. At local scale, LAI is reproduced for tomatoes with a mean RMSE of 0.92 and yield with a RMSE of 1.2 ton ha(-1); while for maize, a RMSE of 1 is found for LAI and a RMSE of 1.5 ton ha(-1) for yield. Results show an overall correspondence of daily soil moisture and evapotranspiration estimates with a RMSE in between 0.11 and 0.15 and of 1.3-3 mm, respectively. At the regional scale, LAI estimates show a RMSE around 1.1 for both case studies, while a RMSE of 13.4 ton ha(-1) is obtained for tomato yield and of 1.4 ton ha-1 for maize