Wednesday, 17 January 2007: 5:00 PM
Beam multiplexing on the NWRT: looking ahead
217A (Henry B. Gonzalez Convention Center)
Beam multiplexing is a weather radar scanning strategy that utilizes the electronic beam steering capability of a phased array antenna. When scanning with a parabolic dish antenna, contiguous samples are collected and processed. With beam multiplexing, the time between transmitted pulses or groups of pulses at a particular beam location is increased which reduces the correlation between samples. Because the samples are less correlated, fewer pulses are transmitted to achieve the same level of errors. The dead time between collections at a given beam location can be used to acquire data at other beam locations so that the radar is in constant use. Decreasing VCP update times is the primary advantage compared to transmitting contiguous pulses, but beam multiplexing also introduces new challenges that need to be considered.
A simple beam multiplexing strategy has been implemented on the National Weather Radar Testbed (NWRT). Weather radar time-series data were collected and analyzed using the phased array radar (PAR) which confirmed earlier theoretical predictions about reductions in VCP times. Because of limitations in the currently implemented approach, we are looking ahead to new approaches that fully realize the potential of beam multiplexing. This paper will introduce the fundamental concepts of beam multiplexing, discuss the advantages and drawbacks, and describe a new approach that addresses some of the limitations of the current strategy.