No abstract

The High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a dual-frequency (Ka-and Ku-bands), dual-beam (30 • and 40 • incidence angles), and conical scanning Doppler radar designed for operation on the NASA high-altitude (∼19 km) Global Hawk Unmanned Aerial System. HIWRAP was developed under the support of the NASA Instrument Incubator Program for studies of tropical storms and severe weather events. It utilizes solid-state transmitters along with a novel transmit and receive waveform scheme that results in a system with compact size, light weight, less power consumption, and lower cost compared to radars currently in use for precipitation and Doppler wind measurements. By combining volume backscattering measurements at Ku-and Ka-bands, HIWRAP is capable of imaging radar reflectivity and 3-D wind fields in clouds and precipitation. In addition, HIWRAP is also capable of measuring surface winds in an approach similar to SeaWinds on QuikSCAT. HIWRAP operating frequencies are similar to those used by the NASA Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar, making it suitable for providing airborne validation data for the GPM mission. This paper describes the scientific motivation for the development of HIWRAP as well as the system hardware, aircraft integration, and recent flight activities. Data from recent science flights are also presented.

A volume-surface electric field integral equation method of moments formulation that makes use of rooftop basis functions defined over prism elements is presented. The new prism elements and their associated basis functions are designed to work either independently or in conjunction with basis functions previously defined over tetrahedral elements. Good agreement is found when comparing results obtained using the present formulation with analytical and experimental results.Index Terms-Antenna input impedance, electric field integral equation, method of moments (MoM), radar cross section.

No abstract

1 Through the NASA Instrument Incubator Program (IIP), NASA, the University of Massachusetts and Remote Sensing Solutions have teamed to design and develop a dual wavelength, dual beam conically scanning Doppler radar for deployment on the NASA Global Hawk platform and other high altitude aircraft. This system is to map the tropospheric, atmospheric, and surface wind fields in and around tropical cyclones by using cloud particles and precipitation as tracers. The design has been completed and the instrument is now being fabricated. To realize this system, innovations in antenna design, transmitter design and measurement processing were required. This paper shall present these innovations and outline the expected performance of this novel system.