ATD'S 1995 Collection

S-POL

Who's Involved: Jon Lutz, project lead; Paul Johnson, fabrication and design lead; Jack Fox, creator of fundamental design; Jeff Keeler and Craig Walther, other contributions
What It Is: Portable, polarized Doppler radar that allows the horizontal and vertical components of returning signals to be measured, thus permitting hail and other storm features to be detected
Claim to Fame: S-POL promises to be the most portable large Doppler radar ever. It is being assembled with parts from an older Doppler radar of the National Severe Storms Laboratory. The entire package fits into six 8- x-8-x-20-foot seatainers for shipment. Four of those seatainers then serve as a base for the radar transmitter/receiver.
First Deployment: Expected this fall in the Maritime Continent Thunderstorm Experiment (MCTEX), which will study tropical convection over Tiwi Island, just north of Darwin, Australia.

Zebra

Who's Involved: Jon Corbet, lead; Cindy Mueller, scientific lead; Anne- Leslie Barrett, Chris Burghart, Kris Gould, Gary Granger, and Rebecca Sobol, developers
What It Is: A system allowing researchers to view and work with disparate types of data in a single graphical interface
Claim to Fame: The vast array of instrumentation in modern field projects required a method by which project scientists could sift through various types of data quickly, both in real-time and post-processing modes. Zeb's software was completed in 1990 for the Convection and Precipitation/Electrification Experiment (CaPE). It has since found use in many field projects and in the ongoing Atmospheric Radiation Measurement (ARM) program of the U.S. Department of Energy. Zebra was in the spotlight at the TOGA COARE data workshop held last fall in Toulouse, France, which was among the first scientific meetings to provide intensive, on-site analysis and display of the data at hand.
First Deployment: Zebra isn't new, but it is continually being refined and its popularity continues to grow. Full documentation is available on ATD's World Wide Web server.

Enhanced ISS

Who's Involved: Hal Cole, Charlie Martin, and Dave Parsons, ISS developers; Stephen Cohn, signal processing
What It Is: A modular system that takes surface and upper-air readings of wind, temperature, moisture, and other variables as often as every 30 minutes, using profilers (clear air radars) and other instruments
Claim to Fame: ISS made its successful debut in the Tropical Ocean and Global Atmosphere Program's Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) in 1992-93. Now the ISS group is enhancing the system in two ways:

• In collaboration with NOAA's Environmental Technology Laboratory (formerly the Wave Propagation Laboratory), a ground-based backscatter lidar is being developed that will allow the ISS to detect nonprecipitating clouds and provide information on aerosols. This lidar complements the ISS profiler's measurements of heavier clouds and precipitation.
• Stephen Cohn and colleagues are refining a way to use multiple receivers to gain far more frequent profiler measurements. A wind profiler measures the wind through pointing its beam in a few near- vertical directions as its signals return to a single receiver. Cohn's technique uses several closely spaced receivers that simultaneously pick up signals, avoiding the need for different beam directions. This approach may slash the time needed per observation from 30 minutes to seconds. The ultimate goal is to have the system simulate a very tall tower, providing turbulent flux information through rapid measurements of wind, temperature, and perhaps eventually water vapor.

PAM III

Who's Involved: Tom Horst, lead; Matt Michaelis, John Militzer, Scott Norris, and Steve Semmer, primary contributors
What It Is: Network of 30 upgraded surface meteorological stations
Claim to Fame: PAM's first and second generations were deployed on projects worldwide from 1978 to 1992. Almost five dozen compact, solar- powered stations gathered basic meteorological data and relayed the data via satellite. The upgraded PAM III stations feature sensors with higher accuracy, lower maintenance, faster satellite data transmission, and the ability to measure solar radiation and frozen precipitation. Ten of the new stations will be Flux-PAMs, measuring the vertical transport of heat, water vapor, momentum, trace gases, and net radiation.
First Deployment: A prototype is being tested at the Marshall site this winter. Three prototypes will be deployed in Florida this summer to support the Small Cumulus Microphysics Study.

GPS Dropwindsonde

Who's Involved: Hal Cole, project manager; Terry Hock and Ken Norris, hardware design; Dean Lauritsen, data system design
What It Is: Small parachute-borne instrument package dropped from airplanes to take measurements over oceans and other regions where launching weather balloons (radiosondes) from the ground is impractical.
Claim to Fame: In the early 1970s, NCAR developed the first research dropwindsonde used globally in field programs and by NOAA and the U.S. Air Force to track and study hurricanes. The Omega-based navigation system for these sondes is being discontinued in the late 1990s. Technology now permits smaller, lighter, and more accurate sensors, along with navigation via GPS satellites. A much narrower bandwidth for transmitting signals from sonde to plane will allow for savings in battery power, weight, and frequency spectrum. The new unit will require only 10% of the transmitting power of its predecessor (one-tenth watt versus one watt), and at around 0.4 kilograms, its weight is one-quarter of the Omega sonde's.
First Deployment: Likely to occur from NOAA's new high-altitude Gulfstream IV during the 1996 hurricane season, with possible deployment from NCAR's RB-57 or C-130 before then. The dropsonde-- cosponsored by NCAR, NOAA, and the German Aerospace Research Establishment (DLR)--will see eventual use in NOAA's P-3 and G-4 planes and in DLR's new stratospheric research aircraft, which can reach heights of nearly 24 kilometers. ATD and DLR are exploring development of an ozone sensor for polar research.

BINET

Who's Involved: Josh Wurman (now at the University of Oklahoma), development; Chuck Frush, Chris Holloway, and Mitch Randall, prototyping
What It Is: Network of low-cost Doppler radar receivers Claim to Fame: BINET uses an array of receivers to pick up signals scattering obliquely from radar targets, thus maximizing the wind data gained from a single Doppler transmitter. It was created by Wurman during his postdoctoral stay at ATD in 1993-94. Although a Doppler radar costs $2 million or more, BINET receivers cost only a small fraction of that. The PIRAQ signal processing technology (see below), originally developed for BINET, should further reduce the cost of receivers.
First Deployment: Testing took place in 1993-94 using the CP-2 transmitter at Marshall and BINET receivers atop the Foothills Lab and near Mead, Colorado. NCAR now has a cooperative agreement with Wurman for continued development. A permanent bistatic network is being deployed around Montreal, Quebec, Canada, in a collaboration between NCAR, Oklahoma, and McGill University.

PIRAQ

Who's Involved: Mitch Randall and Eric Loew, developers
What It Is: A card that turns a personal computer into a complete radar receiver/data acquisition system
Claim to Fame: The inexpensive PIRAQ card opens the door for vastly greater flexibility in radar deployment by compressing the space needed for signal processing from bookshelf-sized units to a single PC card. The programmability allows each user to tailor the configuration as needed. Since it is small and inexpensive, it is ideal for many new research applications.

• The PIRAQ card allows the data from nose-cone weather-avoidance radars in planes such as the Electra and the C-130 to be used for scientific research. Without altering the cockpit weather avoidance displays, the PIRAQ system samples and processes the radar echoes and provides a high-resolution, scientific, Doppler weather display and recording platform.
  
• PIRAQ appears ideal for BINET, which requires multiple, high- performance, remotely located receivers that are small, inexpensive, and reliable.
  
• PIRAQ technology may also play a role in the eventual retrieval of vertical velocity information from ISS profilers.

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