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Automated Volume Scan Evaluation and Termination (AVSET). Field Test Training Presented by Joe Chrisman (ROC) and Jami Boettcher (WDTB). Background. WSR-88D VCPs automatically scan predefined elevation angles
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Automated Volume Scan Evaluation and Termination (AVSET) Field Test Training Presented by Joe Chrisman (ROC) and Jami Boettcher (WDTB)
Background • WSR-88D VCPs automatically scan predefined elevation angles • All VCP elevations scanned regardless of areal coverage or significance of return • VCP update time fixed • All products updated at the fixed VCP completion time interval
Why AVSET? • Faster VCP updates long desired • Rotate the antenna faster? • More hardware stress and lowers base data quality • Sample fewer elevations? • Can’t predefine a VCP for every scenario • Best option is Automated Volume Scan Evaluation and Termination (AVSET)
AVSET in a Nutshell • AVSET makes each volume scan “dynamic” • Number of angles scanned is dependent on the sampled meteorological return • Sampling above the weather? • Then stop the current volume scan and start a new one! • AVSET runs at RDA
How AVSET Works • Terminates volume scan once returns fall below thresholds of dBZ and areal coverage • Shortens time between product updates when no significant data exists on higher elevation tilts • Antenna rotation rates and base data quality do not change! • Details forthcoming…
How AVSET Works • Only analyzes data above 5º • VCP 31 and 32 not impacted by AVSET • To terminate, each condition must be met: • ≥18 dBZ over < 80 km² • ≥ 30 dBZ over <30 km² • areal coverage ≥18 dBZ has not increased by 12 km² or more since the last volume scan • If all three conditions are met…
How AVSET Works • All three conditions met? Yes!! • AVSET terminates the volume scan aftercompletion of the next higher elevation • VCP 212 Example: Below thresholds at 5.1°? Will terminate after 6.4° • AVSET’s thresholds are defaults for now
AVSET and VCP 11 Example • Lowest 4 elevations: 0.5°, 1.5°, 2.4°, and 3.4° • AVSET does no analysis here!
AVSET and VCP 11 Example • Next 4 elevations: 4.3°, 5.3°, 6.2°, and 7.5° • AVSET analyzes 5.3°, 6.2°, and 7.5° and • Returns are above thresholds
AVSET and VCP 11 Example • Next 3 elevations: 8.7°, 10.0°, and 12.0° • Returns fall below AVSET thresholds on 10.0° • 12.0° is sampled as the last elevation • Composite Reflectivity entire coverage
AVSET ProcessingA Closer Look Returns below AVSET Thresholds Last Elevation Processed 10° Elevation we did not scan thanks to AVSET 12° 14° AVSET thresholds expected to be sufficiently sensitive…
How Low Can We Go? • VCP 11 full volume scan time 4 min, 48 sec • AVSET shortest update3 min, 12 sec • VCP 12 full volume scan time 4 min, 18 sec • AVSET shortest update3 min, 12 sec
How Low Can We Go? • VCP 212 full volume scan time 4 min, 36 sec • AVSET shortest update3 min, 30 sec • VCP 21 full volume scan 5 min, 48 sec • AVSET shortest update4 min, 54 sec
AVSET and Range to Weather • AVSET with storms at close range • Entire VCP used • AVSET with storms at far range • Only relevant elevations above 5° used
Areas of Concern • Cone of Silence • Impacts on user systems • Other than bandwidth • Level II Bandwidth Impacts • Shortened volume scan times • More frequent product updates
Cone of Silence • Does AVSET increase the risk of missing elevated convection that develops in the cone of silence? • VCP 31 or 32 and 1st echo of the day • No AVSET impact in Clear Air Mode
Cone of Silence • Worst case so far • Storms at long range; VCP 21; AVSET on; VCP terminates above 6.0° • New elevated cell very near RDA; AVSET not sampling high, but much more often! • Contributor? • Avoid VCP 21 andconvection! Gapsaloft!
Cone of Silence • AVSET thresholds very sensitive • Threshold not met • Anything relevant at higher elevations very unlikely • Rapidly developing convection very close to the radar? • AVSET alsolooks for increase in areal coverage between scans
Cone of Silence • If ≥18 dBZ increased ≥12 km2 at that elevation since last volume scan • AVSET applies even more sensitive thresholds to remaining elevations • ≥18 dBZ over < 30 km2 or ≥30 dBZ over <10 km2 • If below these new thresholds, volume scan terminates after next higher elevation • AVSET results in more frequent sampling to find developing elevated convection
KDMX • Storm cluster northeast • Isolated storm south • One hour intervals
Parkersburg-Dunkerton EF5 Tornado T VCP 212 Osceola EF0-EF1 Tornado T VCP 12 AVSET VCP 212 AVSET VCP 12 9 Tornado Warnings Issued During Period AVSET Volume Scan Average = 3.7 mins AVSET would have provided six additional volume scans
Impacts on User Systems • AVSET exercised at ROC since Spring 2009 • AWIPS – No problems identified • OPUP – No problems identified • FAA User Systems – No problems identified
Bandwidth Impact Analysis • Faster VCP updates => more bandwidth needed to send Level II data • Single site communications load worst case increase of 25-30% • Cumulative network load cannot be estimated using worst case single site figures National Radar Mosaic from Aug 7, 2008 21:48Z
Analysis Method Radar Used In Analysis Level II Not Available • 29 of 34 radars in area included in analysis • Level II data unavailable for five radars • Level II data replayed for 2100Z-2259Z on RPG with AVSET • No Clear Air VCP data used
Bandwidth Impact Analysis Conclusion • Out of 29 sites… • 1 had increase of > 30% • 4 had increase of 20 - 30 % • 6 had increase of 10 – 20 % • 8 had increase of 1 - 10% • 10 had 0 or < 1% increase • Average Level II bandwidth increase over the region due to AVSET < 10 %
Field Test Specifics.. • Test Objectives • Why are we doing this test? • User Control • Schedule and Participating Sites • Reporting results
Field Test Objectives • Verify that AVSET supports forecast and warning operations • Verify that AVSET does not adversely affect the operation of NEXRAD during active weather periods • Verify AVSET-produced volume scans with varying completion durations do not adversely impact • Forecast and warning operations • User data processing and display systems
User Control • AVSET part of RPG Build 12.0 software; however… • Only AVSET Field Test sites (you!) get the “turn it on” software • Will also receive the “Test Log” • AVSET Enable/Disable toggle at RPG HCI
User Control:AVSET Rules of Engagement • AVSET default state is “Disabled” • Automatically disabled with any switch to Clear Air Mode (VCP 31 or 32) • AVSET must be enabled manually • When any Precipitation Mode VCP is active, AVSET can be activated • Once selected, AVSET status PENDING until start of next volume scan
User Control:AVSET Rules of Engagement • During Field Test period, use AVSET as often as possible • If for any reason you become uncomfortable with AVSET, disable it • Please record on the Test Log reason(s) for not using AVSET for the particular event
User Control:AVSET Rules of Engagement • Send FTM to all users each time AVSET manually enabled or disabled • Console Message windowfrom RPG Control/Status
User Control:AVSET Rules of Engagement • Also… • Please record date/time when AVSET is enabled or disabled in the Test Log
AVSET Field Test:Your Users • For the DoD and FAA users… • If you feel AVSET is compromising your systems or your ability to perform your mission… • First contact the WSR-88D Hotline • 1-800-643-3363 • Hotline will verify the problem and will issue request to disable AVSET • Please record request & reason in Test Log
Field TestParticipants • NWS • Southern Region: • Norman, OK (KTLX) and Melbourne, FL (KMLB) • Central Region: • Goodland, KS (KGLD), Indianapolis, IN (KIND), Pueblo, CO (KPUX), and St. Louis, MO (KLSX) • Eastern Region: • Sterling, VA (KLWX) and State College, PA (KCCX) • Western Region: • Glasgow, MT (KGGW) and Tucson, AZ (KEMX)
Field TestParticipants • USAF AFWA • 25th OWS, Davis-Monthan AFB, AZ • Associated to KEMX, KPUX, and KGGW • 15th OWS, Scott AFB, IL • Associated to KLWX, KCCX, KLSX, and KIND • 26th OWS, Barksdale AFB, LA • Associated to KTLX, KLSX, and KMLB • FAA • Indianapolis ARTCC, Indianapolis, IN • Associated to KIND
Here’s What We Know So Far • AVSET can reduce volume scan duration ≤ 100 s • Bandwidth: • Per site Level II increase ~28% • Per connection narrowband increase ~25% • “Regional” Bandwidth increases ~10% • Dual Pol bandwidth upgrade expected to support AVSET • Cone of Silence: • Enhanced logic to address rapid cell growth close to radar • Sampling much more often during cell growth time • No impacts to user systems identified
AVSET Future Plans • Thank you for your participation! • Really couldn’t do it without you • Given successful completion of AVSET Field Test… • Brief NEXRAD SREC on Field Test Results • Gain approval to include AVSET in Build 13 • Submit CCR to make AVSET operational in Build 13
Questions? • Joe Chrisman (ROC Engineering) • Joe.n.chrisman@noaa.gov • AVSET Developer and Field Test Director • Work Phone: 405-573-3335 • Cell Phone: 405-694-5025 • Can address content, test procedures, logistics • Jami Boettcher (WDTB) • Jami.b.boettcher@noaa.gov • Can address content