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New Radar Technologies

This page presents information on some of the new and exciting changes being developed or recently implemented in the WSR-88D

VCP 112-New VCP for Multi-PRF Dealiasing Algorithm (MPDA) Replaces VCP 121

In VCP 112 for split cuts, the MPDA combines velocity data from a high PRF SZ-2 Doppler scan (upper right) with a lower PRF SZ-2 Doppler scan (lower right) to create a velocity product (lower left) with much reduced range folding (purple haze). The Reflectivity image (upper left) is shown for reference.


Velocity SZ-2 PRF8

Click for a larger image Click for a larger image

Combined SZ-2 Velocity from PRFs8 and 4

Velocity SZ-2 PRF4

Click for a larger image Click for a larger image
Sample Volume Completion Times

# RDA Scans

# RPG Scans AVSET SAILS Low Elv. Time (sec) Time (mm:ss)
15 9 6.4 Off No 272 04:32
20 14 N/A Off No 322 05:22
23 15 N/A On No 385 06:25
26 16 N/A On Yes 447 07:27

Sample Slide Sets of VCP 112 Data Cases
FOP1_2018_05_02_23_48_37.bz2 N/A No
FOP1_2018_05_03_00_07_25.bz2 N/A No
FOP1_2018_05_03_00_26_13.bz2 N/A No
FOP1_2018_05_03_00_45_28.bz2 N/A No
FOP1_2018_05_03_01_04_43.bz2 N/A No
FOP1_2018_05_03_01_23_07.bz2 N/A No
FOP1_2018_05_03_01_41_45.bz2 N/A No
FOP1_2018_05_03_01_59_38.bz2 N/A No
FOP1_2018_05_03_02_18_18.bz2 N/A No
FOP1_2018_05_03_02_37_33.bz2 N/A No
FOP1_2018_05_03_02_56_32.bz2 N/A No
FOP1_2018_05_03_03_14_51.bz2 N/A No
FOP1_2018_05_03_03_32_46.bz2 N/A No
FOP1_2018_05_03_03_52_02.bz2 N/A No
FOP1_2018_05_03_04_11_16.bz2 N/A No
FOP1_2018_05_03_04_29_48.bz2 N/A No
FOP120180914143338V06.raw N/A No
FOP120180914143924V06.raw 6.4 Yes
FOP120180914144506V06.raw 6.4 Yes
FOP120180914145048V06.raw 6.4 Yes
FOP120180914145633V06.raw N/A Yes
FOP120180915120049V06.raw N/A Yes
FOP120180915120741V06.raw N/A Yes
FOP120180915121432V06.raw N/A Yes
FOP120180915122122V06.raw N/A Yes
FOP120180915122813V06.raw N/A Yes
FOP120180915123504V06.raw N/A Yes
FOP120180915124154V06.raw N/A Yes
FOP120180915124846V06.raw N/A Yes
FOP120180915125537V06.raw N/A Yes

MRLE – A New Way of Interrogating Storm Mid-Levels

The Mid-Volume Rescan of Low-Level Elevations (MRLE) function is based on the proven SAILS concept. However instead of only rescanning the lowest elevation like SAILS, MRLE rescans the lowest “N" elevations (where “N" can either be 1, 2, 3, or 4 elevations). MRLE rescans the elevations in the middle (by time) of the volume scan.

(Click image for larger version)

For more information select the following links:



Level II Data – The following Level II data files are provided to exercise with MRLE.

File Name VCP MRLE
KOUN_2016_10_26_13_58_31.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_49_27.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_40_38.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_31_32.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_22_43.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_14_50.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_13_06_22.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_57_45.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_49_18.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_40_40.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_32_28.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_23_50.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_15_25.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_12_06_36.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_11_58_03.bz2 VCP 215 MRLEx4
KOUN_2016_10_26_11_50_14.bz2 VCP 215 MRLEx4

VCP 215
(Click image for larger version)
(Click Here for more Information)

Level II Data – The following Level II data files are provided to exercise VCP 35 and VCP 215.

VCP 35
GZIP files from NCEI Raw RPG files
ROP420150930_080157_V06.gz ROP420150930080157V06.raw
ROP420150930_080908_V06.gz ROP420150930080908V06.raw
ROP420150930_081620_V06.gz ROP420150930081620V06.raw
ROP420150930_082332_V06.gz ROP420150930082332V06.raw
ROP420150930_083044_V06.gz ROP420150930083044V06.raw
ROP420150930_083756_V06.gz ROP420150930080157V06.raw
ROP420150930_084507_V06.gz ROP420150930084507V06.raw
ROP420150930_085219_V06.gz ROP420150930085219V06.raw
ROP420150930_085931_V06.gz ROP420150930085931V06.raw
ROP420150930_090644_V06.gz ROP420150930090644V06.raw

VCP 215
GZip files from NCEI Raw RPG files
ROP420150930_050546_V06.gz ROP420150930050546V06.raw
ROP420150930_051203_V06.gz ROP420150930051203V06.raw
ROP420150930_051821_V06.gz ROP420150930051821V06.raw
ROP420150930_052438_V06.gz ROP420150930052438V06.raw
ROP420150930_053055_V06.gz ROP420150930053055V06.raw
ROP420150930_053712_V06.gz ROP420150930053712V06.raw
ROP420150930_054328_V06.gz ROP420150930054328V06.raw
ROP420150930_054946_V06.gz ROP420150930054946V06.raw
ROP420150930_055603_V06.gz ROP420150930055603V06.raw
ROP420150930_060220_V06.gz ROP420150930060220V06.raw
ROP420150930_060837_V06.gz ROP420150930060837V06.raw

Additional data may be requested from NCEI (formerly NCDC) for ROP4 for 09/29/15 1908UTC through 09/30/15 1258UTC. VCP 35 and VCP 215 were executed during the following time periods.

VCP 35 09/29/15 1908 -1951
VCP 215 09/29/15 1958 -2300
VCP 35 09/29/15 2306 - 09/30/15 0040
VCP 215 09/30/15 0047 - 0748
VCP 35 09/30/15 0801 - 0928
VCP 215 09/30/15 0935 - 1258

Multiple Elevation Scan Option for SAILS
The Next Step in the Continuing Evolution of Dynamic Scanning

Building on concept of SAILS, the Multiple Elevation Scan Option for SAILS allows the operator to select either one, two or three supplemental low-level elevation scans (verses only one supplemental scan allowed in the initial SAILS implementation) per VCP (ONLY available with VCP 12 and VCP 212).


Level II Data – The following Level II data files are provided to exercise systems with all three SAILS options.

File Name SAILS State Number of SAILS Scans
KOUN_2014_02_04_18_28_55.bz2 SAILS OFF 0 Supplemental Scans
KOUN_2014_02_04_18_32_02.bz2 SAILSx1 1 Supplemental Scan
KOUN_2014_02_04_18_35_41.bz2 SAILSx1 1 Supplemental Scan
KOUN_2014_02_04_18_39_19.bz2 SAILSx2 2 Supplemental Scans
KOUN_2014_02_04_18_43_31.bz2 SAILSx2 2 Supplemental Scans
KOUN_2014_02_04_18_47_41.bz2 SAILSx2 2 Supplemental Scans
KOUN_2014_02_04_18_51_53.bz2 SAILSx3 3 Supplemental Scans
KOUN_2014_02_04_18_56_36.bz2 SAILSx3 3 Supplemental Scans
KOUN_2014_02_04_19_01_21.bz2 SAILSx2 2 Supplemental Scans
KOUN_2014_02_04_19_05_34.bz2 SAILSx3 3 Supplemental Scans

Dynamic Scanning

Dynamic Scanning - VCP duration and product availablilty comparisons underscore the advantages of using AVSET and SAILS during severe weather events.

Severe Weather VCP Duration: This table lists the average VCP duration based on AVSET termination angle (VCP 12 and 212 include SAILS).

Product Availability Comparison: This table compares the number of products available per hour with and without AVSET and SAILS executing.

Benefits of Dynamic Scanning (PDF)

Operational Improvements to the AUTO PRF Function

Storm-Based AUTO PRF


The Auto PRF algorithm has been in the WSR-88D since the beginning. This algorithm works well but it simply selects the Doppler PRF that results in the least amount of range folded (purple) data for the entire area within a 230 km radius of the radar without consideration for the importance of any individual storm. To address this limitation, the ROC is working on a Storm-Based AUTO PRF function to augment the legacy AUTO PRF algorithm.

Storm_Based_Auto_PRF_ Investigation_Report.pdf


To accommodate the requirement for SZ-2 to have 64 pulses per radial, the PRFs for all SZ-2 VCPs are hard coded. The hard coded PRFs result in the second trip clutter induced range folding bins to always be at a constant range for each VCP. While in most circumstances this is a manageable issue, under some conditions the inability to change the location of the second trip clutter induced range folded data can have a detrimental impact on the forecast and warning process. To address this deficiency, the ROC is implementing an automated PRF selection capability for the three SZ-2 VCPs (VCP 212, VCP 211 and VCP 221). This new SZ-2 Auto PRF Function determines the optimum PRF (Storm-Based or Legacy, as selected by the operator) and modifies the antenna rotation rate to maintain the 64 pulses per radial requirement.

We are encouraged by early testing of testing the SZ-2 Auto PRF function. Please check back later for more detailed information.

Supplemental Adaptive Intra-Volume Low-Level Scan (SAILS)

A scanning method to reduce the elapsed time between 0.5° elevation scans.

Level II Data
(Click image for larger version)

SAILS may not be recommended for every radar due to existing bandwidth limitations.

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Enhanced Velocity Azimuth Display Wind Profile (EVWP)

The Enhanced Velocity Azimuth Display Wind Profile (EVWP) function is designed to improve the availability and accuracy of VWP wind estimates.

  Original (left), Enhanced VWP (right)

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Automated Volume Scan Evaluation and Termination (AVSET)

Two-Dimensional Velocity Dealiasing Improvement Algorithm