Scanning ARM cloud radar development

Description

Through the 2009 American Recovery and Reinvestment Act, the U.S. DOE’s Pacific Northwest National Laboratory recently funded ProSensing Inc. of Amherst, Massachusetts to build six dual-frequency cloud radar systems. These radars will be used by the Atmospheric Radiation Measurement (ARM) Climate Research Facility for fundamental research on the effects of clouds and precipitation on the climate. Four cloud radar systems will be permanently installed in Oklahoma, Alaska, Australia, and Papua New Guinea, while two portable systems will be deployed with ARM’s mobile facilities (AMF1 and AMF2) at sites around the world. The Scanning ARM Cloud Radar (SACR) systems will deployed in pairs operating at X-band and Ka-band or at Ka-band and W-band. The X-band systems will employ a high average power (200 W) Travelling Wave Tube Amplifier while the Ka-band and W-band systems will use an Extended Interaction Klystron amplifier, with average powers of 100 W and 15 W, respectively. The X- and Ka-band systems will be deployed on separate pedestals at the ARM sites in Darwin, Australia and Manus Island, Papua New Guinea and with AMF1. The paired Ka/W-band system will be deployed at the Southern Great Plains and Barrow, Alaska ARM sites and with AMF2. The Ka/W-band system will use beam-matched antennas deployed on a common heavy-duty scanning pedestal. The SACR RF units will include an embedded arbitrary waveform generator (AWG), allowing use of custom pulse compression waveforms. A separate AWG is used for frequency hopping to speed estimation of spectral moments. The RF units each have an integrated PC-based data acquisition system, using a high performance 16-bit, 120 MS/s digital receiver. Custom processing features are being developed, including frequency hopping, staggered PRF, and optimally weighted pulse compression filters.