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The problem of making radar measurements of meteorological phenomena such as rainfall, clouds, and ice crystal formation from a satellite is discussed. The main problem areas are obtaining sufficient signal-to-noise ratio within the weight limitation of the satellite system and avoiding ground clutter when scanning any significant angle off nadir. Sufficient signal-to-noise ratio to detect heavy rainfall at 35 GHz is available for a downlooking only system within the weight power limitation of the Military Meteorological Satellites. An arrested aperture doppler system to reject ground clutter at large scan angles off nadir while detecting rainfall by doppler due to its vertical motion is suggested. ; "Microwave Physics Laboratory Project 5635." ; ADA003385 (from http://www.dtic.mil). ; "30 September 1974." ; Includes bibliographical references (page 27). ; The problem of making radar measurements of meteorological phenomena such as rainfall, clouds, and ice crystal formation from a satellite is discussed. The main problem areas are obtaining sufficient signal-to-noise ratio within the weight limitation of the satellite system and avoiding ground clutter when scanning any significant angle off nadir. Sufficient signal-to-noise ratio to detect heavy rainfall at 35 GHz is available for a downlooking only system within the weight power limitation of the Military Meteorological Satellites. An arrested aperture doppler system to reject ground clutter at large scan angles off nadir while detecting rainfall by doppler due to its vertical motion is suggested. ; Mode of access: Internet.

BALTRAD software exchanges weather-radar data internationally, operationally, and in real-time, and it processes the data using a common toolbox of algorithms available to every node in the decentralized radar network. This approach enables each node to access and process its own and international data to meet its local needs. The software system is developed collaboratively by the BALTRAD partnership, mostly comprising the national Meteorological and Hydrological institutes in the European Union's Baltic Sea Region. The most important sub-systems are for data exchange, data management, scheduling and event handling, and data processing. C, Java, and Python languages are used depending on the sub-system, and sub-systems communicate using well-defined interfaces. Software is available from a dedicated Git server. BALTRAD software has been deployed throughout Europe and more recently in Canada. Funding statement: From 2009–2014, the BALTRAD and BALTRAD+ projects were part-financed by the European Union (European Regional Development Fund and European Neighbourhood and Partnership Instrument), with project numbers #009 and #101, respectively.

This paper describes a methodology for processing spectral raw data from Micro Rain Radar (MRR), a K-band vertically pointing Doppler radar designed to observe precipitation profiles. The objective is to provide a set of radar integral parameters and derived variables, including a precipitation type classification. The methodology first includes an improved noise level determination, peak signal detection and Doppler dealiasing, allowing us to consider the upward movements of precipitation particles. A second step computes for each of the height bin radar moments, such as equivalent reflectivity (Ze), average Doppler vertical speed (W), spectral width (s), the skewness and kurtosis. A third step performs a precipitation type classification for each bin height, considering snow, drizzle, rain, hail, and mixed (rain and snow or graupel). For liquid precipitation types, additional variables are computed, such as liquid water content (LWC), rain rate (RR), or gamma distribution parameters, such as the liquid water content normalized intercept (Nw) or the mean mass-weighted raindrop diameter (Dm) to classify stratiform or convective rainfall regimes. The methodology is applied to data recorded at the Eastern Pyrenees mountains (NE Spain), first with a detailed case study where results are compared with different instruments and, finally, with a 32-day analysis where the hydrometeor classification is compared with co-located Parsivel disdrometer precipitation-type present weather observations. The hydrometeor classification is evaluated with contingency table scores, including Probability of Detection (POD), False Alarm Rate (FAR), and Odds Ratio Skill Score (ORSS). The results indicate a very good capacity of Method3 to distinguish rainfall and snow (PODs equal or greater than 0.97), satisfactory results for mixed and drizzle (PODs of 0.79 and 0.69) and acceptable for a reduced number of hail cases (0.55), with relatively low rate of false alarms and good skill compared to random chance in all cases (FAR 0.70). The methodology is available as a Python language program called RaProM at the public github repository ; This research was funded by the Spanish Government through projects CGL2015-65627-C3-1-R, CGL2015-65627-C3-2-R (MINECO/FEDER), CGL2016-81828-REDT and RTI2018-098693-B-C32 (AEI/FEDER). ; Postprint (published version)

Attenuated backscatter measurements from a Vaisala CL31 ceilometer and a modified form of the well-known slope method are used to derive the ceilometer extinction profiles during rain events, restricted to rainfall rates (RRs) below approximately 10 mm/h. RR estimates from collocated S-band radar and portable disdrometer are used to derive the RR-to-extinction correlation models for the ceilometer-radar and ceilometer-disdrometer combinations. Data were collected during an intensive observation period of the Verification of the Origins of Rotation in Tornadoes Experiment Southeast (VORTEX-SE) conducted in northern Alabama. These models are used to estimate the RR from the ceilometer observations in similar situations that do not have collocated radar or the disdrometer. Such correlation models are, however, limited by the different temporal and spatial resolutions of the measured variables, measurement capabilities of the instruments, and the inherent assumption of a homogeneous atmosphere. An empirical method based on extinction and RR uncertainty scoring and covariance fitting are proposed to solve, in part, these limitations. ; This work was supported by the National Oceanic and Atmospheric Administration (NOAA) under Grant NA1501R4590232 and Grant NA16OAR4590209 and by the Department of Earth, Atmospheric, and Planetary Sciences, Purdue University. CommSensLab-Universitat Politècnica de Catalunya (UPC) (which is a María de Maeztu Excellence Unit funded by the Agencia Estatal de Investigación, Spain; MDM-2016-0600) collaborated via Spanish Government - European Regional Development Funds under PGC2018-094132-B-I00 and TEC2015- 63832-P projects, and via European Union (funds) (EU) Funds under Grant H2020 ACTRIS-2 (GA-654109) and Grant ACTRIS-PPP (GA-739530). The work of Rubén Barragán was supported by the Spanish Ministry of Science, Innovation and Universities under Grant BES-2013-066340. ; Peer Reviewed ; Postprint (published version)

[PT] The main input information for empty rain models is precipitation; a fundamental variable of the hydrological cycle with characteristics that depend on its type. The aim since work is to analyse the impact of different ways of measuring precipitation on rainfall exits. Hydrological simulations were performed with the IPH II model for 3 precipitation datasets as input to the model: (1) rainfall, (2) radar rain, (3) radar plus rainfall — rain analysed. The area chosen for carrying out the study was the Barigüi river basin in the Metropolitan Metropolitan Region Paraná. The results indicated that rainfall measures show good results for stratified precipitation events. On the other hand, simulations for precipitation events with irregular spatial distribution did not perform well. In addition, hydrological simulations with precipitation estimated by radar alone did not give satisfactory results, either underestimating or suppressing the voids. The best results were produced with the precipitation field analysed with ANOBES. Adilson Moreira, I.; Moro Mine, M.; Pereira Filho, A. (2007). Rain empty hydrological modelling with radar data and rainfall. Ingeniería del agua. 14 (2): 83-96. https://doi.org/10.4995/ia.2007.2904 Beneti C.A.A., Nozu I. y Saraiva E.A., (1998). Monitoring precipitation and severe weather radar events in the state of Paraná. EN: Brazilian Meteorology Congress, X. CD-ROM, Brasilia. Beneti, C.A.A., Calvetti L. and Pereira Filho A.J., (2002). Estimate of the Precipitation by Radar and Pluviômeters in the Metropolitan Region of Amsterdam — Preliminary Results. EN: Brazilian Meteorology Congress, XI. CD-ROM, Foz do equaçu. Calvetti L., Beneti C. y Pereira Filho, A.J., (2003). Integration of Simepar dopller meteorological radar and a rainfall network for precipitation estimation. EN: Brazilian Symposium Remoto sensory Symposium, XI. CD-ROM, Belo Horizon. Gonçalves F.M., (2005). Use of Meteorological Radar in Hydrology. Thesis (Master's in Engineering) 116 f — Polytechnic School of the University ...

May 1995. ; Also issued as Peter Clark Clement's thesis (M.S.) -- Colorado State University, 1995. ; Includes bibliographical references. ; Accurate precipitation measurement is desired over large areal extents in fine temporal and spatial resolution for a myriad of scientific disciplines and practical applications. Hydrological sciences and federal and local government agencies would benefit from improved precipitation measurements. The question is can radars satisfy this desire for better precipitation measurements. The WSR-88D radar network will provide nearly complete radar coverage of the contiguous United States and has the ability to operationally measure large areal extents in fine temporal and spatial resolutions. Precipitation products derived from the WSR-88D networks are becoming readily more accessible and steadily gaining in popularity and use, often without any reference to accuracy. This study is a comparison of precipitation from the CSU-CHILL multiparameter research radar, National Weather Service's WSR-88D located outside Denver, CO (KFTG), and networks of tipping bucket gages. Comparisons are made to reveal spatial coverage of precipitation, time distribution of precipitation, and quantify amounts of precipitation derived from the two radars and gage networks from three convective precipitation events in northeastern Colorado. This study finds the multiparameter variable, specific differential phase derived precipitation (R(KDP)) compared well with gage precipitation for rainfall accumulations greater than 1 cm. On 20 June 1994 for 12 gages with four-hour accumulated precipitation greater than 1 cm, the R(KDP) to gage precipitation ratio was 0.89. On 21 June 1994 for 3 gages with one-hour accumulated precipitation greater than 1 cm, the R(KDP) to gage ratio was 1.37. For precipitation accumulations less than 1 cm, R(KDP) greatly overestimated gage precipitation which is consistent with previous findings. On 20 June at one gage site (FOR) with a known 30- minute period of mixed phase ...

In 1998, the Naval Postgraduate School (NPS) Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) and the NPS Department of Electrical and Computer Engineering (ECE Dept.) collaborated on the acquisition of a mobile radar, the AN/MPQ-64 (Sentinel). This is a modern X-band, pulse Doppler radar used by the Army for forward area air defense. An SBIR project funded by the Office of Naval Research resulted in a contract to ProSensing, Inc., Amherst, MA to retrofit this radar with a weather processor. The intent is to provide a military capability to assess battlespace weather in real time. This capability will be developed using the NPS radar as a testbed. When the weather capability has been fully implemented on the NPS radar, it will also have application as a scientific instrument for severe storm research because of its mobility and cutting-edge capabilities. The modified radar has been designated the MWR-05XP (Mobile Weather Radar, 2005, X-band, Phased Array). This report presents the results of an analysis of numerous aspects of the radar's performance as a weather sensor. The ability of the MWR-05XP radar to detect rain with different levels of reflectivity, the ability of the radar to detect clear air turbulence with different structure parameters and echoes from birds and insects has been examined. Curves are provided to determine correlation and decorrelation times for weather signals with varying rms velocity spread. MWR-05XP post detection integration improvement has been computed for a Rayleigh weather target with varying pulse-to-pulse correlation and curves are provided to determine the improvement in terms of the number of pulses integrated. Lastly, scan strategy is discussed with emphasis on obtaining weather signal parameter estimates with small variance while at the same time achieving a rapid volumetric update rate. Electronic scan is the feature that enables the radar to achieve a rapid volumetric update rate. Data quality control is also discussed. ; Approved for public release; distribution is unlimited.

Póster presentado en: 10th European Conference on Radar in Meteorology and Hydrology celebrado en Wageningen, Países Bajos, del 1 al 6 de julio de 2018. ; This study was partly supported by projects CGL2015-65627-C3-2-R (MINECO/FEDER), CGL2016-81828-REDT (MINECO) and DI065/2017 (Industrial Doctorate Programme of the Regional Government of Catalonia)

Academic, government, and private organizations from around the globe have established High Frequency radar (hereinafter, HFR) networks at regional or national levels. Partnerships have been established to coordinate and collaborate on a single global HFR network (http://global-hfradar.org/). These partnerships were established in 2012 as part of the Group on Earth Observations (GEO) to promote HFR technology and increase data sharing among operators and users. The main product of HFR networks are continuous maps of ocean surface currents within 200 km of the coast at high spatial (1–6 km) and temporal resolution (hourly or higher). Cutting-edge remote sensing technologies are becoming a standard component for ocean observing systems, contributing to the paradigm shift toward ocean monitoring. In 2017 the Global HFR Network was recognized by the Joint Technical WMO-IOC Commission for Oceanography and Marine Meteorology (JCOMM) as an observing network of the Global Ocean Observing System (GOOS). In this paper we will discuss the development of the network as well as establishing goals for the future. The U.S. High Frequency Radar Network (HFRNet) has been in operation for over 13 years, with radar data being ingested from 31 organizations including measurements from Canada and Mexico. HFRNet currently holds a collection from over 150 radar installations totaling millions of records of surface ocean velocity measurements. During the past 10 years in Europe, HFR networks have been showing steady growth with over 60 stations currently deployed and many in the planning stage. In Asia and Oceania countries, more than 110 radar stations are in operation. HFR technology can be found in a wide range of applications: for marine safety, oil spill response, tsunami warning, pollution assessment, coastal zone management, tracking environmental change, numerical model simulation of 3-dimensional circulation, and research to generate new understanding of coastal ocean dynamics, depending mainly on each country's coastal sea characteristics. These radar networks are examples of national inter-agency and inter-institutional partnerships for improving oceanographic research and operations. As global partnerships grow, these collaborations and improved data sharing enhance our ability to respond to regional, national, and global environmental and management issues.

Academic, government, and private organizations from around the globe have established High Frequency radar (hereinafter, HFR) networks at regional or national levels. Partnerships have been established to coordinate and collaborate on a single global HFR network (http://global-hfradar.org/). These partnerships were established in 2012 as part of the Group on Earth Observations (GEO) to promote HFR technology and increase data sharing among operators and users. The main product of HFR networks are continuous maps of ocean surface currents within 200 km of the coast at high spatial (1–6 km) and temporal resolution (hourly or higher). Cutting-edge remote sensing technologies are becoming a standard component for ocean observing systems, contributing to the paradigm shift toward ocean monitoring. In 2017 the Global HFR Network was recognized by the Joint Technical WMO-IOC Commission for Oceanography and Marine Meteorology (JCOMM) as an observing network of the Global Ocean Observing System (GOOS). In this paper we will discuss the development of the network as well as establishing goals for the future. The U.S. High Frequency Radar Network (HFRNet) has been in operation for over 13 years, with radar data being ingested from 31 organizations including measurements from Canada and Mexico. HFRNet currently holds a collection from over 150 radar installations totaling millions of records of surface ocean velocity measurements. During the past 10 years in Europe, HFR networks have been showing steady growth with over 60 stations currently deployed and many in the planning stage. In Asia and Oceania countries, more than 110 radar stations are in operation. HFR technology can be found in a wide range of applications: for marine safety, oil spill response, tsunami warning, pollution assessment, coastal zone management, tracking environmental change, numerical model simulation of 3-dimensional circulation, and research to generate new understanding of coastal ocean dynamics, depending mainly on each country's coastal sea characteristics. These radar networks are examples of national inter-agency and inter-institutional partnerships for improving oceanographic research and operations. As global partnerships grow, these collaborations and improved data sharing enhance our ability to respond to regional, national, and global environmental and management issues.

International audience The calibration of the CloudSat spaceborne cloud radar has been thoroughly assessed using very accurate internal link budgets before launch, comparisons with predicted ocean surface backscatter at 94 GHz, direct comparisons with airborne cloud radars, and statistical comparisons with ground-based cloud radars at different locations of the world. It is believed that the calibration of CloudSat is accurate to within 0.5 to 1 dB. In the present paper it is shown that an approach similar to that used for the statistical comparisons with ground-based radars can now be adopted the other way around to calibrate other ground-based or airborne radars against CloudSat and/or detect anomalies in long time series of ground-based radar measurements, provided that the calibration of CloudSat is followed up closely (which is the case). The power of using CloudSat as a Global Radar Calibrator is demonstrated using the Atmospheric Radiation Measurement cloud radar data taken at Barrow, Alaska, the cloud radar data from the Cabauw site, The Netherlands, and airborne Doppler cloud radar measurements taken along the CloudSat track in the Arctic by the RASTA (Radar SysTem Airborne) cloud radar installed in the French ATR-42 aircraft for the first time. It is found that the Barrow radar data in 2008 are calibrated too high by 9.8 dB, while the Cabauw radar data in 2008 are calibrated too low by 8.0 dB. The calibration of the RASTA airborne cloud radar using direct comparisons with CloudSat agrees well with the expected gains and losses due to the change in configuration which required verification of the RASTA calibration.

International audience ; In 1970, Henri Dessens, director of the Clermont-Fd Observatory, wanted to use radar to study the physics of the atmosphere. The idea became a reality with Serge Godard, who took over from Dessens at the head of the Observatory. He succeeded in recovering a military radar that was diverted from its original function to become a study and research instrument called ANATOL (ANAlyse et Trajectoire d'Orages Locaux). ANATOL's long career came to an end in 1995 after more than 45 years of good and loyal service in atmospheric research. However, the idea of using radars continued to grow and in 1993, under the direction of Daniel Ramon, an ST (Stratosphere-Troposphere) radar was installed with Météo-France. Then, in the mid-1990s, Jacques Kornprobst, director, launched the Observatory on the design and technical production of a prototype "volcanological" Doppler radar, VOLDORAD-1. Responding to volcanological needs, it was tested in a pioneering way at Etna in 1998. This success led to the construction of two other unique volcanological radars (VOLDORAD-2 and 2B) and a third (VOLDORAD-3). Since 2002, these radars have been combined into a dedicated observation service within the OPGC and are used for monitoring volcanic eruptions but also for atmospheric studies. ; En 1970, Henri Dessens, directeur de l'Observatoire de Clermont-Ferrand, souhaite utiliser des radars pour l'étude de la physique de l'atmosphère. L'idée se concrétise avec Serge Godard, qui prend la suite de Dessens à la tête de l'Observatoire. Il réussit à récupérer un radar militaire qui va être détourné de sa fonction première pour devenir un instrument d'étude et de recherche baptisé ANATOL (ANAlyse et Trajectoire d'Orages Locaux). La longue carrière d'ANATOL s'achève en 1995 après plus de 45 ans de bons et loyaux services dans la recherche atmosphérique. Mais l'idée d'utiliser des radars poursuit son chemin et dès 1993, sous la direction de Daniel Ramon, c'est l'installation d'un radar ST (Stratosphère-Troposphère) menée avec ...

International audience ; In 1970, Henri Dessens, director of the Clermont-Fd Observatory, wanted to use radar to study the physics of the atmosphere. The idea became a reality with Serge Godard, who took over from Dessens at the head of the Observatory. He succeeded in recovering a military radar that was diverted from its original function to become a study and research instrument called ANATOL (ANAlyse et Trajectoire d'Orages Locaux). ANATOL's long career came to an end in 1995 after more than 45 years of good and loyal service in atmospheric research. However, the idea of using radars continued to grow and in 1993, under the direction of Daniel Ramon, an ST (Stratosphere-Troposphere) radar was installed with Météo-France. Then, in the mid-1990s, Jacques Kornprobst, director, launched the Observatory on the design and technical production of a prototype "volcanological" Doppler radar, VOLDORAD-1. Responding to volcanological needs, it was tested in a pioneering way at Etna in 1998. This success led to the construction of two other unique volcanological radars (VOLDORAD-2 and 2B) and a third (VOLDORAD-3). Since 2002, these radars have been combined into a dedicated observation service within the OPGC and are used for monitoring volcanic eruptions but also for atmospheric studies. ; En 1970, Henri Dessens, directeur de l'Observatoire de Clermont-Ferrand, souhaite utiliser des radars pour l'étude de la physique de l'atmosphère. L'idée se concrétise avec Serge Godard, qui prend la suite de Dessens à la tête de l'Observatoire. Il réussit à récupérer un radar militaire qui va être détourné de sa fonction première pour devenir un instrument d'étude et de recherche baptisé ANATOL (ANAlyse et Trajectoire d'Orages Locaux). La longue carrière d'ANATOL s'achève en 1995 après plus de 45 ans de bons et loyaux services dans la recherche atmosphérique. Mais l'idée d'utiliser des radars poursuit son chemin et dès 1993, sous la direction de Daniel Ramon, c'est l'installation d'un radar ST (Stratosphère-Troposphère) menée avec ...

International audience ; In 1970, Henri Dessens, director of the Clermont-Fd Observatory, wanted to use radar to study the physics of the atmosphere. The idea became a reality with Serge Godard, who took over from Dessens at the head of the Observatory. He succeeded in recovering a military radar that was diverted from its original function to become a study and research instrument called ANATOL (ANAlyse et Trajectoire d'Orages Locaux). ANATOL's long career came to an end in 1995 after more than 45 years of good and loyal service in atmospheric research. However, the idea of using radars continued to grow and in 1993, under the direction of Daniel Ramon, an ST (Stratosphere-Troposphere) radar was installed with Météo-France. Then, in the mid-1990s, Jacques Kornprobst, director, launched the Observatory on the design and technical production of a prototype "volcanological" Doppler radar, VOLDORAD-1. Responding to volcanological needs, it was tested in a pioneering way at Etna in 1998. This success led to the construction of two other unique volcanological radars (VOLDORAD-2 and 2B) and a third (VOLDORAD-3). Since 2002, these radars have been combined into a dedicated observation service within the OPGC and are used for monitoring volcanic eruptions but also for atmospheric studies. ; En 1970, Henri Dessens, directeur de l'Observatoire de Clermont-Ferrand, souhaite utiliser des radars pour l'étude de la physique de l'atmosphère. L'idée se concrétise avec Serge Godard, qui prend la suite de Dessens à la tête de l'Observatoire. Il réussit à récupérer un radar militaire qui va être détourné de sa fonction première pour devenir un instrument d'étude et de recherche baptisé ANATOL (ANAlyse et Trajectoire d'Orages Locaux). La longue carrière d'ANATOL s'achève en 1995 après plus de 45 ans de bons et loyaux services dans la recherche atmosphérique. Mais l'idée d'utiliser des radars poursuit son chemin et dès 1993, sous la direction de Daniel Ramon, c'est l'installation d'un radar ST (Stratosphère-Troposphère) menée avec Météo-France. Puis, au milieu des années 1990, Jacques Kornprobst, directeur, lance l'Observatoire sur la conception et la réalisation technique d'un prototype de radar « volcanologique » à effet Doppler, VOLDORAD-1. Répondant à des besoins en volcanologie, il fut testé de façon pionnière sur le site de l'Etna en 1998. Ce succès conduisit dans la foulée à la construction de deux autres radars uniques en volcanologie (VOLDORAD-2 et 2B) puis d'un troisième (VOLDORAD-3). Réunis en un service d'observation dédié au sein de l'OPGC depuis 2002, ces radars sont utilisés pour la surveillance des éruptions volcaniques mais également pour des études atmosphériques.