CASA : NSF Center for Collaborative Adaptive Sensing of the Atmosphere Dr. José Colom-Ustáriz
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.
“There is insufficient knowledge about what is actually happening (or is likely to happen) at the Earth’s surface where people live.” [NRC 1998]
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
This System “underneath” NEXRAD Water spout at Mayaguez, PR- Sept 2005
CASA: dense networks of low power radars Year 5 of a 10 year program
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
We’re not going to do this alone! Industrial, government, and academic outreach partners
¿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.
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
What is a Radar? Radio detection and ranging 1.How does a radar work? 2.Games
hello Compare to: Acoustic Echo-location
hello Acoustic Echo-location
hello distance Acoustic Echo-location
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
RADAR Echolocation ( RADAR ~ RAdio Detection And Ranging) “Microwave Echo-Location” Microwave Transmitter Receiver Tx Rx
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
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
Target Radial Velocity Frequency f t Frequency f t + f d
Target Radial Velocity Frequency f t Frequency f t + f d
Zero Velocity for “Crossing Targets” Frequency f t Frequency f t + f d Doppler Frequency
0.1 mm/hr 1 mm/hr 15 mm/hr 100 mm/hr >150 mm/hr QPE – Quantitative Precipitation Estimation
Play the games to learn the basics
More Games for Kids
References The COMET project [ NASA TRMM NCAR (National Center for Atmospheric Research) - University Corporation for Atmospheric Research (UCAR) NOAA Educational Page [ Dave McLaughlin Basics of Radars presentation NWS [