This page presents information on some of the new and exciting changes being developed or recently implemented in the WSR-88D
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.
Draft Build 14 ICDs
RPG to Class 1 ICD (pdf)
RDA to RPG ICD (pdf)
Product Specification ICD (pdf)
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
Product Availability Comparison: This table compares the number of products available per hour with and without AVSET and SAILS
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.
AUTO PRF for SZ-2 VCPs
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
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.
|(Click image for larger version)
SAILS may not be recommended for every radar due to existing bandwidth limitations.
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.
Automated Volume Scan Evaluation and Termination (AVSET)
Two-Dimensional Velocity Dealiasing Improvement Algorithm