Research Experience with the CSU-CHILL National Radar Facility:A unique inter-disciplinary experience in Science and Engineering.

V. Chandrasekar and Joseph Hardin

Program Director Program Coordinator

Colorado State University Fort Collins, CO

CSU-CHILL Radar Facility

The CSU-CHILL Radar is an advanced, transportable dual-polarized S-Band weather radar system. The CSU-CHILL radar facility is operatedby Colorado State University under the sponsorship of the National Sci-ence Foundation and the University. The radar serves as an advancedresearch instrument for radar meteorology, radar engineering, and re-mote sensing. The CSU-CHILL features a high-power dual-Klystronpower amplifier, sophisticated transmitter controller, low side lobe an-tenna, and digital receiver system. Radar operations are performedthrough an interactive radar control system which communicates withthe radar system through a TCP/IP connection. Local and remoteusers can observe radar data in real-time, while the archival systemcan store both the processed radar measurements such as reflectivityand Doppler velocity as well as the digitized base band signal.

Figure 1: CSU-CHILL

Sample Research Project from Summer 2011

Analysis of Two Central Oklahoma Tornadoes.

This project focused on combining data from the CASA radar networkwith the national weather service’s NEXRAD radars to analyze thetornadoes that caused significant damage to Oklahoma in the Summerof 2010. A complete weather analysis of the pre-storm environmentand supercell genesis has been performed and includes a synopsis ofupper-level support, surface and satellite observations, and frontal mo-tion across the area.A timeline of significant events during the stormslifetime, including tornado watches, warnings, as well as a comprehen-sive damage report (including photos and videos) was compiled to showthe severity of the storm system. The case study results show that se-vere atmospheric instability coupled with surface heating and moistair advection created perfect ingredients for severe storm convection,which led to the formation of several hook echoes on radar.

Figure 2: Radar data showing the tornado.

RFCalibration

Setup

Klystron

LNA,Receivers

DigitalModulator

MotionController

RAIDArray

Radar Trailer OperationsTrailer

Internet

Dual-ChDigitizers

RadarTiming and

Control

Klystron

LNA,Receivers

Archiver ArchiveServer

SignalProcessor

Gateway

LocalDisplay and

Control

MicrowaveLink

RemoteDisplay and

Control

Google Earth

Figure 3: Layout of the CSU-CHILL radar.

Sample Research Project from 2011

Cloud Photogrammetry and Dual-Polarization DopplerRadar Measurements.

This project involves the use of cloud photogrammetry in associationwith dual-polarization Doppler radar measurements to provide a uniqueanalysis of developing severe weather.Motivation for this project comesfrom a need to understand the physical processes within developingcumulus clouds and to recognize those processes by visual inspection ofthe clouds as well as radar analysis. In order to achieve this goal, thisproject works innovatively with the Colorado State University-CHILL(CSU-CHILL) National Radar and its Virtual-CHILL (VCHILL) pro-gram to access collected radar data. Developing cumulus clouds, precip-itation shafts, and other prominent cloud characteristics are analyzedthrough inspection of multi-parameter radar data.This research will be presented at the AMS Stu-dent conference this year.

Figure 4: Results of Combining Dual-Pol Radar andPhotogrammetry

Figure 5: End of year presentations.

The REU Student Experience

The Student Experience Field Trips OutreachIn addition to the research activity that students carry over the summerthey are also expected to regularly present their results and give pre-sentations on techniques and research that will be valuable to the restof the research community. These weekly meetings help to ensure stu-dents stay on track and gain experience with presenting their researchto peers.

Students work hard, but also get to have many educational and funfield trips to nearby areas of interest. This includes Ponnequin WindFarm, New Belgium, UCAR/NCAR, and the Energy Conversion Labat CSU, and many more.

Students also get the opportunity to network with many high levelpeople in their field. These opportunities are invaluable as it providesthem with the chance to really learn about their future careers as wellas providing contacts for future opportunities.

Figure 6: Weekly student presentations.

This research was sponsored by NSF grant AGS-1004286

Figure 7: Students on a field trip.

Figure 8: Students meeting Professor Paul Smith