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The ROC Software Engineering (ROC/SWE) section provides a variety of support for users of the WSR-88D system. The principle support includes the development, maintenance, enhancement, and problem analysis of software for WSR-88D operational systems. Software Engineers are continuously implementing and testing software modifications that have been requested by NEXRAD users through their respective agencies: the Department of Defense, the Department of Transportation, and the Department of Commerce. Software Engineering also corrects software defects affecting field operations, and applies security Operating System Updates to maintain our authorization to operate.

Software Engineering's workload is primarily divided between the components of the NEXRAD WSR-88D: the Radar Data Acquisition (RDA), the Radar Products Generator (RPG) and the Master System Control Function (MSCF). The MSCF hosts operator user interfaces to the RDA and RPG, providing command, control and status monitoring for the WSR-88D system.

Software Engineering maintains the Archive Level 2 monitoring and radar data distribution software, also known as National Level 2 (NL2). The NL2 project is responsible for ensuring valuable WSR-88D radar data is reliably distributed to the Level 2 user community in real-time. Software Engineering also maintains a Level 2 status page showing Level 2 statistics including radar status, operating mode, and data distribution latency values for all WSR-88D and TDWR/SPG network sites (see

Software Engineering conducts wind farm proposal analyses. In collaboration with wind farm developers, Software Engineering determines whether proposed wind farm turbines penetrate the Radar Line Of Site (RLOS) and if so, to what degree. Significant RLOS penetration negatively impacts radar data quality, including the reliable estimation of rainfall rates and accumulations.

Software Engineering maintains radar coverage maps to show NEXRAD Volume Coverage Pattern (VCP) 12 bottom-of-beam and TDWR VCP 80 bottom-of-beam coverage at 3,000, 6,000, and 10,000 feet above ground level. Radar coverage maps and beam blockage data are also generated to support radar moves and low elevation angle studies.

News & Information:


  • RDA/RPG Build 21.0:

    RDA Build 21.0 removes the Coherency-Based Thresholding (CBT) Enable/Disable Button from the RDA HCI. Prior to Build 21.0, CBT could be disabled as there were potential data quality issues running SZ2 VCPs with CBT enabled. Recent changes to the SZ2 algorithm make the need for CBT to be manually disabled unnecessary. CBT will be enabled by default all the time starting with Build 21.

    RPG Build 21 changes the Velocity Measurement Increment (VMI) at RPG instead of at the RDA. The VMI can be set to 0.5 m/s or 1.0 m/s by the RPG operator. The 1.0 m/s resolution is recommended during tropical weather events when the velocities can be quite large. Any changes to the VMI would change the velocity data in the Level 2 stream as the velocity increment was applied at the RDA. With this change, the VMI will be changed to the RPG instead of the RDA. Consequently the Level 2 velocity data will always be 0.5 resolution.

    In Build 21, the AWIPS operator will also be able to change the VMI using the AWIPS Command/Control capability.

    Starting in Build 21.0, the RPG will report ZDR bias information in the Shift Change Checklist (SCC) product. The ZDR Bias Weighted Mean value derived from external targets (Snow, Bragg and Light Rain) can be used for monitoring by field personnel. A daily weighted mean value, matching the Data Quality Dashboard on the RPG HCI, will be reported. The value will be updated once a day on the first volume for that date (immediately on or following a 00:00 UTC timestamp). The SCC product is distributed to AWIPS once an hour at the top of the hour.

    Build 21 adds the Rain Rate Classification (RRC) algorithm/product. This product provides the user information on which rain rate relationships were used to derive the rain rate estimates. Included in this change is the removal of the edit capability for the Ice Crystal (IC) Multiplier in Dual Pol Precipitation adaptation data. The IC multiplier will be set to the same value as the Dry Snow (DS) Multiplier.

    Build 21 adds a Restart Failed Tasks button to the RPG Control HCI GUI. This button can be used to restart failed RPG tasks without the need to restart the entire RPG.

    Build 21 removes 4-bit (16 data level) Reflectivity products 19 and 20, and the 4-bit Velocity product 27. Products 19 and 20 are still generated at the RPG to support the Clutter Censor Zone Editor and PRF Editor, but will not be made available to external users.

    RDA/RPG Build 21 also includes numerous bug fixes, minor enhancements, and OS patches to improve security.

    RDA/RPG Build 21.0 has been deployed to field sites.

  • RDA/RPG Build 21.1:

    RDA/RPG Build 21.1 is an RDA/RPG OS security patch release and is currently in System/Operations testing.

    RDA/RPG Build 21.1 is, currently, being deployed.

  • RDA/RPG Build 22.0:

    RDA/RPG is primarily a migration of Red Hat Enterprise Linux (RHEL) 7 to RHEL 8 but also includes numerous bug fixes and minor enhancements.

    Build 22 will include improvements to the FAA's Icing Hazards Layers (IHL), and the Super-Resolution Data-Quality Edited Algorithm and Product (SRQ).

    Build 22 will remove Clear Air VCP 32 from the baseline. Site-specific VCPs are being added for Paducah, KY (Base Tilt of 0.3 deg elevation), Pendleton, OR (Base Tilt of 0.2 deg elevation), Springfield, MO (Base Tilt of 0.2 deg elevation), Corpus Christi, TX (Base Tilt of 0.3 deg elevation), and Grand Junction, CO (Base Tilt of 0.0 deg elevation).

    Build 22 will include improvements to the velocity dealiasing algorithm in environments of high shear. It also includes changes to support long-term software maintenance.

    Build 22 adds an RDA Control Command to turn off the sending of RDA logs to the RPG. This could be used to reduce wideband utilization during heavy wideband loads. RDA logs are currently sent from the RPG to the ROC via LDM to support field operations and troubleshooting.

    Build 22 adds minor improvements to the SZ2 algorithm used in VCPs 212, 215, 112, and 35. A new Correlation Coefficient estimator is being added to the baseline as well as non-operational.

    Build 22 will include full support for the Receiver/Signal Processor (RSP) replacement. This allows for the RSP deployment schedule to be untied to Build 22 software deployment.

    Build 22 will automate the Default Storm Speed/Direction from Model Data. The update time will be displayed on the RPG HCI Environmental Data Editor and included in the Shift Change Checklist (SCC) product.

    Build 22 will apply the RPG estimate of Initial System Differential Phase (ISDP) in the DP preprocessor by default.

    Build 22 will generate the Super Resolution Digital Velocity product (154) on all elevation angles of the VCP. The products above the split cuts will be identical to the Digital Velocity product (99).

    Build 22 is currently in formal Operations Test and is scheduled to be released to the field in the Winter, 2023.

  • RDA/RPG Build 23.0:

    Build 23.0 will allow the MSCF/RPG Operator the ability to release RDA (Local) control to the RPG (Remote). This capability will be password protected.

    Build 23.0 will include the VCP number in the RDA Status message associated with the Remote VCP Received acknowledgment. The VCP number will be added to the Remote VCP Received acknowledgment message posted to the RPG Status Log.

    Build 23.0 will include improvements to the Dual Pol Algorithms, specifically 1) reduce/eliminate impacts from bad RPG Initial System Differential Phase (ISDP) estimates on R(A), and 2) reset the RPG estimated ISDP whenever the ISDP value changes at the RDA. The RPG estimated ISDP will be applied by default.

    Build 23.0 will include improvements to the 2D Velocity Dealiasing algorithm.

    Build 23.0 will fix a bug in the RPG that caused the Power Removed Control (PRC) product from being generated.

    Build 23.0 will remove the following unused products from the RPG: 1) Layer Composite Reflectivity Maximum (LRM, Code 65), 2) Radar Code Message (RCM, Code 74), 3) Composite Reflectivity Edit for AP (CRE, Code 98), and 4) Clutter Likelihood Doppler (CLV, Code 133).

    Build 23.0 will add a new Long Pulse VCP 34. VCP 34 will execute in under 9 mins, scan at the same angles as VCP 35 but will be capped at 4.5 deg elevation, and will maintain similar data accuracy as VCP 31.

    Build 23.0 will include several RPG HCI ported from X/Motif to GTK+. The functionality will be preserved. The look and feel will be slightly different.

    Build 23.0 is currently in development. Build 23.0 is scheduled for deployment in Fall, 2024.

  • National Level (NL2) Build 12.0:

    NL2 Build 12.0 was deployed in May 2022 and included changes to remove support for RDA & RPG data prior to Build 19, add support for RDA & RPG data for Build 21, add the fuel level to the Performance/Maintenance data tab on the NEXRAD Map view web page, add support for the Hammond, LA to be established in 2023, and OS security updates to Red Hat Enterprise Linux 7.

  • NL2 Build 12.1:

    NL2 Build 12.1 was deployed in October 2022 and included updates to mail server addresses, an update to the LSI StorageAuthority software, a fix to the NL2 database, an update to provide NPN data to the NCEP/EMC, and OS security updates to Red Hat Enterprise Linux 7.

  • NL2 Build 12.2:

    NL2 Build 12.2 is scheduled for deployment in May 2023 and to include OS security updates for Red Hat Enterprise Linux 7, corrects the IP address for the Hammond radar, corrects the IP address of one of the Purdue clients in an RDS configuration file, and cleans up the scripts used during installations.

  • NL2 Build 13.0:

    NL2 Build 13.0 is scheduled for deployment in October 2023 and to include upgrading to Red Hat Enterprise Linux 8.