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 productMaximum range = 248 nm
8-bit 1 deg azimuth Reflectivity productMaximum 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 SRM Legacy, 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.
TVS graphic product; Super-Res 0.5 SRM
Source: WDTB DLOC Topic 5