Precipitation products from the hydrology SAF

Abstract. The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) was established by the EUMETSAT Council on 3 July 2005, starting activity on 1 September 2005. The Italian Meteorological Service serves as Leading Entity on behalf of twelve European member countries. H-SAF products include precipitation, soil moisture and snow parameters. Some products are based only on satellite observations, while other products are based on the assimilation of satellite measurements/products into numerical models. In addition to product development and generation, H-SAF includes a product validation program and a hydrological validation program that are coordinated, respectively, by the Italian Department of Civil Protection and by the Polish Institute of Meteorology and Water Management. The National Center of Aeronautical Meteorology and Climatology (CNMCA) of the Italian Air Force is responsible for operational product generation and dissemination. In this paper we describe the H-SAF precipitation algorithms and products, which have been developed by the Italian Institute of Atmospheric Sciences and Climate (in collaboration with the international community) and by CNMCA during the Development Phase (DP, 2005–2010) and the first Continuous Development and Operations Phase (CDOP-1, 2010–2012). The precipitation products are based on passive microwave measurements obtained from radiometers onboard different sun-synchronous low-Earth-orbiting satellites (especially, the SSM/I and SSMIS radiometers onboard DMSP satellites and the AMSU-A + AMSU-B/MHS radiometer suites onboard EPS-MetOp and NOAA-POES satellites), as well as on combined infrared/passive microwave measurements in which the passive microwave precipitation estimates are used in conjunction with SEVIRI images from the geostationary MSG satellite. Moreover, the H-SAF product generation and dissemination chain and independent product validation activities are described. Also, the H-SAF program and its associated activities that currently are being carried out or are planned to be performed within the second CDOP phase (CDOP-2, 2012–2017) are presented in some detail. Insofar as CDOP-2 is concerned, it is emphasized that all algorithms and processing schemes will be improved and enhanced so as to extend them to satellites that will be operational within this decade – particularly the geostationary Meteosat Third Generation satellites and the low-Earth-orbiting Core Observatory of the international Global Precipitation Measurement mission. Finally, the role of H-SAF within the international science and operations community is explained.</p

The validation service of the hydrological SAF geostationary and polar satellite precipitation products

Abstract. The development phase (DP) of the EUMETSAT Satellite Application Facility for Support to Operational Hydrology and Water Management (H-SAF) led to the design and implementation of several precipitation products, after 5 yr (2005–2010) of activity. Presently, five precipitation estimation algorithms based on data from passive microwave and infrared sensors, on board geostationary and sun-synchronous platforms, function in operational mode at the H-SAF hosting institute to provide near real-time precipitation products at different spatial and temporal resolutions. In order to evaluate the precipitation product accuracy, a validation activity has been established since the beginning of the project. A Precipitation Product Validation Group (PPVG) works in parallel with the development of the estimation algorithms with two aims: to provide the algorithm developers with indications to refine algorithms and products, and to evaluate the error structure to be associated with the operational products. In this paper, the framework of the PPVG is presented: (a) the characteristics of the ground reference data available to H-SAF (i.e. radar and rain gauge networks), (b) the agreed upon validation strategy settled among the eight European countries participating in the PPVG, and (c) the steps of the validation procedures. The quality of the reference data is discussed, and the efforts for its improvement are outlined, with special emphasis on the definition of a ground radar quality map and on the implementation of a suitable rain gauge interpolation algorithm. The work done during the H-SAF development phase has led the PPVG to converge into a common validation procedure among the members, taking advantage of the experience acquired by each one of them in the validation of H-SAF products. The methodology is presented here, indicating the main steps of the validation procedure (ground data quality control, spatial interpolation, up-scaling of radar data vs. satellite grid, statistical score evaluation, case study analysis). Finally, an overview of the results is presented, focusing on the monthly statistical indicators, referred to the satellite product performances over different seasons and areas

The interpretation of a complex picture and its sensitivity to frontal damage : A reappraisal

A.R. Luria introduced the interpretation of a meaningful picture as a tool for assessing pre-frontal impairment. We gave this test to 196 normal adults, who were asked to communicate what was happening in the portrayed scene (a boy chases a mouse hidden under a cupboard, while three frightened girls assist). The same subjects were given two other frontal tests (verbal fluency on phonemic cue and Trail Making Test (TMT)) and Raven's Matrices. Twenty-three normal subjects (12%) failed to correctly interpret the picture. We also examined 20 patients whose brain lesion encroached upon pre-frontal areas, in order to check if this version of the test could be easily administered to this type of patient, and if its difficulty level was appropriate for avoiding ceiling and floor effects. Twelve patients were unable to interpret the picture (60%). A similar failure rate was observed with the same subjects on verbal fluency and TMT, while Raven's Matrices were less impaired (35%). Some dissociation was found between Picture Interpretation and the TMT. The Italian version of the Picture Interpretation Test is suitable for the examination of pre-frontal patients

Mirror asymmetry of category and letter fluency in traumatic brain injury and Alzheimer's patients

In this study we contrasted the Category fluency and Letter fluency performance of 198 normal subjects, 57 Alzheimer's patients and 57 patients affected by traumatic brain injury (TBI). The aim was to check whether, besides the prevalence of Category fluency deficit often reported among Alzheimer's patients, the TBI group presented the opposite dissociation. According to some recent claims, in fact, the deficit of TBI would be equally severe for both fluency types. The inquiry followed different approaches for data analysis, including the evaluation of a unique index (Fluency Type Index or FTI), independent of the overall fluency and aimed at expressing at individual subject level the relationship between Category and Letter fluency. The results confirmed that Alzheimer's patients are more defective on Category than Letter fluency, and also clearly indicated that an opposite pattern applies to TBI patients. TBI seems to cause a relatively more severe impairment of Letter than Category fluency, probably due to its impact on the frontal lobe structures. We discuss whether, on the basis of the statistical distribution of our data, it is worth considering as homogeneous populations broadly defined groups as Alzheimer's or TBI patients

Apraxia is not associated to a disproportionate naming impairment for manipulable objects

The relevance of gesture knowledge for the semantic representation of manipulable objects was investigated in a series of 15 patients with a focal left-hemisphere lesion. The patients were classified according to the presence/absence of ideomotor and ideational apraxia. We investigated picture naming and word-picture matching (pointing to a picture on verbal command) with stimuli including items from three categories: manipulable objects, non-manipulable objects, and animals. The analysis was performed at group level and at single-patient level. Nine patients were affected by ideational apraxia and nine by ideomotor apraxia: two cases presented ideomotor but not ideational apraxia, and two cases presented the opposite dissociation. Patients affected by ideational apraxia were more severely impaired in all tasks, but did not show a disproportionate impairment with the category of manipulable objects in contrast to the other categories. The presence of ideomotor apraxia did not cause a greater impairment in any task or category. Finally, we observed a patient with ideational apraxia who performed flawlessly in naming and word-picture matching for all the stimuli, including manipulable objects. In conclusion, we did not find a relationship between ideational apraxia and a disproportionate impairment of the semantic knowledge of manipulable objects

The double dissociation between the knowledge of gestures and the actual object use. A study of two patients

Concerning the debate about the relationship between gesture representation related to tools and semantic action knowledge, we focus our attention on the gesture concepts necessary for performing a skilled tool-use and on their possible nature, semantic versus presemantic. We present 14 patients who were examined for praxis abilities with our Apraxia Battery and discuss their performance related to most common cognitive model for praxis. 14 patients with different etiology (6 cortico-basal disease, 1 possible Alzheimer\u2019s disease with atypical onset and 7 left hemispheric strokes) perform an Apraxia Battery composed of 8 tasks (semantic questionnaire, denomination task, verbal recognition tasks, utilization apraxia task, pantomime comprehension , gesture similarity judgment, functional-manipulation similarity judgment, and De Renzi\u2019s imitation test for ideomotor apraxia). All the degenerative patients underwent to a general neuropsychological examination to assess the cognitive profile and the patients with stroke received the Token Test to assess the present of aphasia. Among all patient, we found two patient who present an opposite performance on GSJ task and the manipulation part of the FMSJ one. The patient A (CBD patient) and B (left thalamic stroke patient) performs normal in manipulation similarity judgment part, while shows difficulties in GSJ. On the other hand patient C (CBD patient) shows the opposite pattern (pathological performance in GSJ and preserved abilities in MSJ task. As we suppose, Gesture Similarity Judgment task examine the gesture representations through a semantic route by verbal modality, while the Manipulation Similarity Judgment task explores them though a direct visual modality. We believe that patient A and B present unimpaired gesture representations to a presemantic level, but show a possible deficit at semantic level or a interrupted link between action semantic knowledge and peripheral representations