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Published byGervase Rice Modified over 9 years ago
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CASA : NSF Center for Collaborative Adaptive Sensing of the Atmosphere Dr. José Colom-Ustáriz
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Global Warming and Weather One of the expected consequences of global warming is extreme weather events such as; Hurricane intensity Number of Tornadoes We therefore NEED, better detection, monitoring, prediction and modeling is needed.
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“There is insufficient knowledge about what is actually happening (or is likely to happen) at the Earth’s surface where people live.” [NRC 1998]
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Observation Limitations NEXRAD Rainfall 1 Hour Total Single NEXRAD (TJUA) in PR Distance Cayey to Mayagüez: ~ 100km Site Elevation: 850 m Curvature Beam Elevation (Above Site): 600 m Total Beam Elevation (Above SL): 1.4 km
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This System “underneath” NEXRAD Water spout at Mayaguez, PR- Sept 2005
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CASA: dense networks of low power radars Year 5 of a 10 year program
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What’s needed to solve this problem? Remote sensing Microwave engineering Networking Distributed systems Numerical prediction Emergency management Radar meteorology Quantitative inversion Climate studies Social impact Antenna design core partners expertise working together
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We’re not going to do this alone! Industrial, government, and academic outreach partners
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¿Qué tenemos en Puerto Rico ? Dos Radares – PR1 y PR2 (EWR) Proveen medidas de Reflectividad Radares son single-pol & no son Doppler. Datos se ha colectado durante tormentas de lluvia.
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Puerto Rico IP3 Test Bed Off-the-Grid Radar 1er nodo bajo prueba en UMass PR1 (Stefani) Radar FCC permiso otorgado. Radar operacional falta reemplazomagnetron OTG localización se basa en Modelo de Vulnerabilidad a Desastres QPE MC&C distribuido Optimización Energía Balanceada Comunicaciones Inalámbricas Algoritmo estimación de Reflectividad en Red EWR Radar
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What is a Radar? Radio detection and ranging 1.How does a radar work? 2.Games
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hello Compare to: Acoustic Echo-location
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hello Acoustic Echo-location
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hello distance Acoustic Echo-location
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Hi !! time t = 2 x range / speed of sound Example: range = 150 m Speed of sound ≈ 340 meters/second t = 2 X 150 / 340 ≈ 1 second
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RADAR Echolocation ( RADAR ~ RAdio Detection And Ranging) “Microwave Echo-Location” Microwave Transmitter Receiver Tx Rx
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Target Range time t = 2 x range / speed of light measure t, then determine Range Example: t =.001 sec Speed of light = c = 3x10 8 meters/second Range =.001 x 3x10 8 / 2 = 150,000 m = 150 km Tx Rx
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We will see that Radars work by… Transmitting microwave pulses…. and measuring the … Time delay (range) Amplitude Frequency Polarization … of the microwave echo in each range gate
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Target Radial Velocity Frequency f t Frequency f t + f d
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Target Radial Velocity Frequency f t Frequency f t + f d
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Zero Velocity for “Crossing Targets” Frequency f t Frequency f t + f d Doppler Frequency
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0.1 mm/hr 1 mm/hr 15 mm/hr 100 mm/hr >150 mm/hr QPE – Quantitative Precipitation Estimation
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Play the games to learn the basics http://whyfiles.org http://meted.ucar.edu/hurrican/strike/index.htm http://meted.ucar.edu/hurrican/strike/ http://meted.ucar.edu/hurrican/strike/info_3.htm# http://www.nws.noaa.gov/om/hurricane/index.shtml http://www.nws.noaa.gov/om/edures.htm
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More Games for Kids 4-104 http://www.nws.noaa.gov/om/reachout/kidspage.shtml
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References The COMET project [ http://www.comet.ucar.edu/] NASA TRMM NCAR (National Center for Atmospheric Research) - University Corporation for Atmospheric Research (UCAR) NOAA Educational Page [http://www.nssl.noaa.gov/edu/ideas/radar.html] Dave McLaughlin Basics of Radars presentation NWS [http://www.crh.noaa.gov/fsd/soo/doppler/doppler.htm]
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