As scientists work to improve climate models, one of the most significant uncertainties they need to resolve is a clear understanding and treatment of cloud processes. Observations are critical to achieving this end. The Earth Observing Laboratory (EOL) develops and operates many of the instruments that the U.S. research community relies on to obtain the required high-quality environmental observations for model validation. Among these is EOL's HIAPER Cloud Radar (HCR), which provides researchers with detailed observations of cloud dynamics.

The HCR is one in a suite of instruments developed for the NSF/NCAR Gulfstream V (GV or HIAPER) research aircraft. Before instrument development began, EOL polled the community to identify the right conceptual design of the HCR to support the scientists' climate and weather research. The scientists requested a narrow beam radar capable of detecting and quantifying small amounts of liquid and ice with a second wavelength and/or dual-Doppler capability. They estimated that such a design would significantly extend radar observations' utility by further reducing uncertainty in radar-based measurements of cloud properties.

EOL built the HCR based on this input, but also had to factor in size and weight restrictions because the instrument would fly in a pod attached beneath the GV’s wing. As a result, the HCR became a small, compact radar built in several phases:

  • Phase 0 (complete): Ground based prototype.
  • Phase A (complete): Pod-based W-band radar system with scanning capability.
  • Phase B: Pulse compression will be added for improved sensitivity and polarimetric capability.
  • Phase C: Ka-band radar operating at 35 GHz will be added.

Non-labor portions of Phases A and B were funded through the American Recovery and Reinvestment Act (ARRA) of 2009.