Presentation on theme: "A Refresher on Super-Resolution Radar Data Audra Hennecke, Dave Beusterien."— Presentation transcript:
A Refresher on Super-Resolution Radar Data Audra Hennecke, Dave Beusterien
Base Data Resolution: Legacy vs. Super-Res Base Reflectivity: – Legacy Range Resolution: 1, 2, 4 km (0.54, 1.1, 2.2 nm) Azimuthal Resolution: 1.0 degree – Super-Res Range Resolution: 0.25 km (0.13 nm) Azimuthal Resolution: 0.5 degree Base Velocity: – Legacy Range Resolution: 0.25, 0.50, 1km (0.13, 0.27, 0.54 nm) Azimuthal Resolution: 1.0 degree – Super-Res Range Resolution: 0.25 km (0.13 nm) Azimuthal Resolution: 0.5 degree
Display Ranges Base Reflectivity – Legacy and Super-Res: Both available to 248 nm Base Velocity – Legacy: Available to 124 nm – Super-Res: Available to 162 nm
Super-Res Characteristics Available at lower elevation angles Base data generated for only the Split Cut elevations of the VCPs Retains the highest reflectivity value for display in courser resolutions; preserves important features – i.e. maximum reflectivity values in the cores of strong thunderstorms
Super-Res Reflectivity product Maximum range = 248 nm 8-bit 1 deg azimuth Reflectivity product Maximum range = 248 nm Source: WDTB DLOC Topic 5
Super-Res Base Data Super-Res Base Data, compared to all the base reflectivity/velocity products: – Highest number of data levels (256) – Greatest range resolution (250 m, 0.13 nm) – Best azimuthal resolution (0.5 degree) Base data signatures easier to discern when viewing these higher resolution base data products
Super-Res Base Data Two signal processing techniques used to produce Super-Res base data – Overlapping radials and windowing Windowing process introduces more error in the base data estimate – Results in SR base products being visually noisier than legacy resolution base products – However, it supports visual detection of smaller scale features at longer ranges
Noisy Super-Res Base Data Most apparent with reflectivity (compared to legacy resolution) – 8 SR reflectivity bins for every 1 legacy resolution reflectivity bin More apparent in areas of stratiform precipitation and low returned power Not as apparent in convective areas when compared to stratiform precipitation
SR Base Reflectivity Product Legacy Base Reflectivity Product Source: WDTB DLOC Topic 3 Example of Noisiness for Convective Rainfall
SR Base Reflectivity Product Legacy Base Reflectivity Product Example of Noisiness for Stratiform Rainfall Source: WDTB DLOC Topic 3
Super-Res Base Velocity Range: 162 nm 256 data levels Important velocity features will more readily appear and look clearer with Super-Res products Super-Res velocity magnitudes associated with important signatures may need to be adjusted – May show stronger velocity values than those normally associated with many velocity signatures in the 1 degree data.
Super-Res: SRM 250 m (0.25 km, 0.13 nm) x 0.5 degree Range: 162 nm 256 data levels Displays the highest resolution velocity data available from the radar out to 162 nm for the split cut elevation angles.
Super-Res: SRM High detail (spatially and in data magnitude) provides improved detection of TVSs, mesocyclones, microbursts, and boundaries. Very useful for examining the velocity structure of fast moving storms (> 10kts) – Significant advantage compared to base velocity products of the same resolution
Super-Res: Storm-Scale Features Storm-scale features show up more often and more clearly in Super-Res products. – BWERs, hook echoes, TBSSs, low-level boundaries, hail cores, mesocyclones, TVSs, inflow notches
Super-Res: Mesocyclone Identification Super-res velocity data: typically easier to identify small-scale features, i.e. mesocyclones Velocity magnitudes associated with these features may appear stronger because of the finer resolution in the azimuthal direction
Super-Res SRMLegacy, 1 deg. Azimuth SRM For Super-Res, the strongest velocities associated with the mesocyclone cover a smaller area. Super-res image has a significantly stronger outbound component of the mesocyclone (+43 kts vs +21 kts). Overall storm identification is enhanced. Source: WDTB DLOC Topic 5
Super-Res: TVSs Super-Res velocity: available on the lowest 2-3 elevation angles – Exactly where you would want to look for TVSs Gate-to-gate shear will often have a greater magnitude in Super-Res data than indicated in the TVS definition. – Additional research is needed to understand the relationship between super-res gate-to-gate shear magnitudes and tornadic events.