Hydrometeor Size Distribution Measurements Using Acoustic Impact Transducers John Lane Kennedy Space Center, FL
[email protected] Takis Kasparis University of Central Florida
[email protected] Numerous configurations of impact transducers for the purpose of monitoring rain and hail and their corresponding drop size distributions have been designed and tested. The discrimination of rain drops from hail stones is an important design requirement of a transducer design. Other transducer characteristics affected by design options are hydrometeor response uniformity across the diameter of the sensing head, as well as sensor impulse width affecting coincidence overlap and subsequent measurement lockout time. Test sites for these impact disdrometer prototypes include the roof of the University of Central Florida engineering building, roof of the UCF - Florida Solar Energy Center, and KSC Shuttle Launch Pad 39A. Both UCF sites host collocated Joss-Wadvogel disdrometers which provide comparison measurements of rainfall drop size distributions.
UCF Disdrometer Test Site Roof of Engineering Building
UCF Disdrometer Test Site Roof of Engineering Building
UCF Disdrometer Test Site Roof of Engineering Building
UCF Acoustic Rain Gauge Early Work
• Very low cost • Problems with environmental noise pick‐up. Needs processing • Calibration issues 5
Piezoelectric Sensor
• Very rugged • Totally waterproof • Minimal noise pickup • Non‐uniform sensitivity 6
UCF Rainfall Simulator Civil Engineering
JTD Development Cycle Cyprus University of Technology / University of Central Florida
Dual Head Disdrometer Prototype Cyprus University of Technology / University of Central Florida
Joss Disdrometer Gold Standard
JTD Dual-Head & JWD Cyprus University of Technology / University of Central Florida
JTD Signal Processing Cyprus University of Technology / University of Central Florida Time Domain Signal Calibration
DSD Spectra
Impulse Spectra
CoCoRaHS Hail Pads (Colorado State University)
KSC Hail Transducer
KSC Hail Transducer Calibration
KSC Hail Transducer Calibration - 70 ft Tower Drop
KSC Hail Transducer Calibration - Ice Balls
KSC Hail Transducer In Situ Calibration – Denver, CO
KSC Hail Transducer In Situ Calibration – Denver, CO
Shuttle Launch Pad 39A Three Hail Monitor Sites
Shuttle Launch Pad 39A Hail Monitor Sites
Shuttle Launch Pad 39A Three Hail Monitor Sites
Shuttle Launch Pad 39A NOAA Radar, 3-30-2011, 21:23 GMT
Shuttle Launch Pad 39A NOAA Radar, 3-30-2011, 21:27 GMT
Shuttle Launch Pad 39A Hail Pads, 3-30-2011, 21:27 GMT
Shuttle Launch Pad 39A
Shuttle Launch Pad 39A Size Distribution, 3-30-2011, 21:27 GMT
Shuttle Launch Pad 39A Size Distribution, 3-30-2011, 21:27 GMT
Shuttle Launch Pad 39A Hail Monitor REFERENCES [1] Community Collaborative Rain and Hail Study, Colorado Climate Center, Colorado State University, http://www.srh.noaa.gov/mlb/?n=cocorahs [2] Strong, G.S., and E. P. Lozowski, 1977: An Alberta study to objectively measure hailfall intensity. Atmosphere-Ocean, 4, 33-53. [3] Lozowski, E. P. and G. S. Strong, 1978: On the calibration of hailpads. J. Appl. Meteor., 17, 521-528. [4] Bardsley, W. E., 1990: On the maximum observed hailstone size. J. Appl. Meteor., 29, 1185-1187. [5] Pad-39A Hail Monitor Data Analysis of the February 26, 2007 Hail Event, ASRC Aerospace, Kennedy Space Center, March 2, 2007. [6] 3DRadPlot: Open Channel Software, http://openchannelsoftware.com/projects/3DRadPlot. [7] Analysis of the STS-127 June 27, 2009 Hail Event, ASRC Aerospace, Kennedy Space Center, FL, July 6, 2009.
