The Airborne Millimeter-wave System Development and Performance Update for NCAR's HIAPER Cloud Radar

The High-Performance Instrumented Airborne Platform (HIAPER) is a National Science Foundation (NSF) funded aircraft which supports environmental research. It is a high-altitude, long-endurance Gulfstream V aircraft designed to house a suite of in situ and remote sensing instruments. The Earth Observing Laboratory (EOL) is currently developing a scanning , W-band cloud radar mounted in a wing pod on the HIAPER aircraft (Farquharson et al. 2007, Tsai et al. 2011). The phased approach in designing and developing the so-called HIAPER Cloud Radar (HCR) includes the following steps: the initial ground-based, proof-of-concept prototype; the airborne configuration; dual-polarized, pulse compression airborne system and, the final stage, dual wavelength (W- and Ka-band) system.

The HCR was transitioned into the airborne configuration in 2012. Several intermediate engineering validations were conducted for evaluating its performance – ground validation of the pod-based airborne system, integration with the HIAPER aircraft and finally, flight validation during a test flight in February 2013.

This paper describes the progress to date of HCR development including aircraft integration, calibration and radar performance. The preliminary engineering assessment of the ground-based inter-comparison with the Wyoming Cloud Radar (WCR) showed the two systems were in good agreement. Preliminary data from the test flights are also included to demonstrate the airborne system performance. The high-altitude, aircraft exterior environmental information is included in the analysis of the system stability .

References: P. Tsai, E. Loew, J. Vivekanandan, J. Emmett, C. Burghart, S. Rauenbuehler, 2011: NCAR HIAPER Cloud Radar Design and Development. 35th Conf. on Radar Meteor, 25-30 September , 2011 G. Farquharson, E. Loew, J. Vivekanandan, W. Lee, 2007: A New High-Altitude Airborne Millimeter-Wave Radar for Atmospheric Research. 33rd Conf. on Radar Meteor, 6-10 August, 2007