Profiling Radars In Network Test (FootPRINT)

Project Leader: Bronwyn Dolman (ATRAD)
Project Team: Douglas Gray(UoA) and Marian Viola(UoA)

Funding: Self-funded
Publications relating to this project - NOTE: This will need to be linked before going live or removed

Project background

Long range scanning radars are used globally by both forecasters and researchers to provide information on weather systems. A major limitation in the use of these radars is the Earth's curvature, which results in the radar beam sampling well above the surface at long range gates. A potential solution to this problem is to replace single high-power long-range radars with a network of low-power radars, positioned such that the curvature effect is minimised. An example of this is WREN (Weather Radar Experimental Network), a network of three low cost fully polarimetric digital X-band radars, placed around the Adelaide region. It is anticipated WREN will look at weather phenomena and bushfire activity.

One disadvantage of scanning radars, when used for monitoring rainfall, is their inability to resolve the rainfall drop size distribution (DSD), that is, the number of drops of a given size in a given sample of the atmosphere. Instead, scanning radars must calculate rainfall parameters such as rain-rate via algorithms. Vertically pointing profiling radars, typically operating at VHF or UHF, can directly measure the fall speed of drops, and can convert this, via known fall-speed drop-size relations, to a DSD. Profilers therefore provide accurate descriptions of rainfall, and associated parameters such as rain-rate and liquid water content. The major disadvantage of profiling radars is they are vertically pointing, and can sample only the part of the storm which passes directly overhead.
In combination, a network of scanning radars with a network of profiling radars provides a powerful tool in weather studies. The profiling radars, while effectively acting as point samples, can directly measure the DSD, and can be used to calibrate the scanning network algorithms in near real time.
FootPRINT is a network designed with this purpose in mind.

Project aims

• Build a network of low-cost vertically pointing profiling radars, operating near 450 MHz, within the footprint of the WREN scanning radar network
• Use these profilers to perform DSD retrievals, and use this information to calibrate the algorithms of the WREN network used for calculating rain-rate and median drop diameter
• Experiment with algorithms calculated in near real-time from FootPRINT into WREN