Research and Development


CSU-CHILL is a research and development center with a focus on system-level weather radar design and implementation. These systems are then deployed globally in support of field campaigns to study phenomena of interest to the atmospheric science community. Some of the areas of research and development are summarized below.

System-level radar design and implementation

Design and implementation of weather radar systems is a challenging task involving multiple engineering sub-disciplines. CSU-CHILL has a track record of developing field-deployable weather radars with repeatable performance. System-level design involves interpreting the specifications for a radar system and generating a design based on the specifications within the constraints of budget, time and available hardware.

The implementation phase starts with simulations to verify that the design is feasible, followed by a CAD design. Subsystem procurement and fabrication proceeds after a thorough design review process. After final integration and validation against existing radar systems on site, the radar is ready to deploy.

Microwave Subsystem design and implementation

The microwave subsystem of a weather radar includes the high-power transmitter, duplexer, antenna, waveguide assembly, receiver and frequency conversion chains. The design is challenging to implement due to the simultaneous presence of high RF power (at S-band, this can be up to 1 MW peak power) and very sensitive receivers (sensitive to a few pW). The RF chains must possess high dynamic range to process the large difference in signal levels, while simultaneously being sensitive to weak signals.

CSU-CHILL has extensive experience with developing such systems, and we are constantly expanding our expertise into new frequency bands, power levels and bandwidths. Our RF Instrument Lab provides ample resources for development and testing of new microwave subsystems and hardware.

Signal processing and waveform design

CSU-CHILL has developed a number of radar systems using solid-state radar transmitters, which introduce unique requirements and constraints in terms of radar waveform design and signal processing algorithms. Wide band waveforms require high-bandwidth digital signal processing systems to implement filtering and pulse compression operations, which often require customized signal processing hardware. CHILL has developed a number of FPGA-based data acquisition and processing hardware development that are tailored to the needs of pulse compression radars that operate at a variety of frequency bands and power levels.

Radar processing algorithms

Raw data output from weather radar sensors often requires significant amounts of post-processing to produce quality-controlled data suitable for scientific analysis and presentation. CSU-CHILL has been engaged in the development of radar data processing systems including

  • Moment generation from time-series data using frequency-domain and time-domain methods
  • Ground clutter filtering
  • Rain rate retrieval
  • Dual Doppler wind speed calculations
  • Dual wavelength analysis for hail signature detection
  • Dual-polarization hydrometeor classifiers