Some Good or Foolish Ideas, with Farm Names, Concerning the Future of Adaptable Radar Networks for Severe Storm Observations

COW: Frustrated by the compromise choices of mobile-radar observing with narrow-beam (<1.0-degree) but severely attenuating X-band radars and broader-beam (1.5-degree) more penetrating C-band radars, CSWR has recently developed the C-Band On Wheels (COW). This truck-borne radar has a 12.5 ft dish, which is assembled quickly onsite with a small lightly-trained team, using an on-board crane, with no site preparation. The 1-degree beam antenna provides DOW-like resolution, and the C-band transmissions permit observations deeply into intense precipitation. While not as nimble as the DOWs, the COW can be operational within 2-3 hours at a targeted location. The COW can be disassembled and re-deployed to a different location for nomadic projects like VORTEX-N, RELAMPAGO-N, or PECAN-N. Or the COW can remain for several days or more in a persistent weather regime, moving multiple times during a field project. With the exception of high Plains-type projects such as VORTEX-2, the loss of fast chasing capability is an excellent trade off for fine-scale, penetrating C-band, targeted observational capability. The dual-pol dual-frequency, 2x 1 megawatt COW was first deployed during RELAMPAGO and some preliminary results will be shown.

SOW: Large stationary S-band research radars such as CP-2, S-POL, and CHILL, have been central observing systems in dozens of field projects, contributing critically to major advances in the understanding of a wide range of atmospheric phenomena. Advances in technology, and evolution of the questions being asked by atmospheric scientists, motivate a re-analysis of how best to continue and to move beyond the capabilities of large stationary expensive-to-deploy S-band research radars. An alternative concept, blending the advantages of the DOW/COW paradigm with the benefits of S-band radars, will be presented. Similar to the COW, three to four truck-borne S-band On Wheels (yep, SOW, it’s a farm-animal theme) with modular 18-foot dishes can be deployed in a few hours. Each SOW will have a 1.5-degree beam, but, since there are multiple SOWs in a SOWNET, the typical range to targets will be much less, resulting in comparable spatial resolution to S-POL and CHILL and many similar existing S-band radars. 18-foot dishes have ½ the sail-area, less than ½ of the weight, simplifying/shrinking pedestals, motors, generator needs, etc. SOW arrays can be 2D polygons or linear, and can change during a project, which allows for greater observing flexibility. A major benefit of SOW-Net is multiple-Doppler and multiple independent observations of dual-polarization quantities.

BARN: Everyone who uses Doppler radar data wishes that they had true 3D vector wind data. Multiple-Doppler data are the foundation to many research objectives, but the underlying multiple monostatic radar deployments are expensive, and the process of preparing data for research-quality vector windfield retrievals is both time consuming and smooths out small-scale temporal and spatial features through objective analysis. Bistatic radar networks, tested in the 1990’s, provide a low-cost, and less-smoothed both temporally and spatially, alternative. Advances in low-cost computational capability, and high-speed cellular communications make bistatic networks much easier to establish. CSWR proposes to construct a network of bistatic receivers, carried by small pick up trucks, surrounding each DOW/COW/SOW, to provide 3D unsmoothed vector wind fields whenever DOWs/COW/SOWs are deployed. Bistatic Adaptable Radar Network (BARN).