Following the Phase 2 wire-up of real METAR data, two user-visible items on the /weather page were inaccurate and have been corrected. First, the “Operations by Weather Condition” chart was binding to total flights per condition rather than the per-day rate; readers were comparing buckets of unequal denominators. Bars now show average operations per day of each condition with the total surfaced in the tooltip, matching the per-day framing already used in the Key Insights below the charts.

Second, a paragraph at the bottom of the /weather page still described historical weather correlation as “estimated weather pending verified historical-NOAA ingestion” — stale text from before the Phase 2 wire-up. The paragraph now describes the real KJPX-primary / KFOK-fallback sourcing consistent with the inline disclosure card above it.

No underlying data or methodology changes; the corrections are to chart bindings and attribution text. Companion clarity improvements landed in the same change — the Wind Rose title was extended to acknowledge that lobe length encodes operations frequency while color encodes average noise (both true), the Daily Weather & Operations Timeline gained a fixed “Ops” y-axis reference and bottom-anchored bars to remove visual ambiguity, and the per-chart KJPX/KFOK source-attribution tooltip now explains that 100% / 0% reflects observed coverage during the visible date range rather than implying KFOK is non-functional.

The Weather Correlation page at /weather previously rendered charts using deterministic estimated weather, with an inline disclosure acknowledging the limitation (see the prior “Weather correlation provenance” entry below). The page now queries real historical METAR observations from KJPX (East Hampton Airport, the primary source) with KFOK (Francis S. Gabreski Airport, Westhampton) as fallback for gaps in KJPX's reporting. Each chart shows the source distribution as “Data: KJPX X% / KFOK fallback Y%”.

Wind rose join. Operations are now bucketed into the wind rose by the wind direction at the actual hour each operation occurred, not by the day's aggregate dominant direction. The hourly join is more accurate when intraday wind shifts are large.

Source. Observations are sourced from the Iowa Environmental Mesonet, an academic archive maintained by Iowa State University that ingests from NOAA's authoritative feeds (Unidata IDD, NCEI ISD, MADIS One Minute ASOS). The backfill spans 2020-01-01 onward; KJPX covers approximately 98% of days and KFOK fills the remaining ~2%.

Coverage gaps. The Weather Correlation page's summary stats strip dropped its “Avg Humidity” cell because the daily summary view does not aggregate humidity. The other four cells (Avg Temp, Avg Wind, Avg Visibility, Period) are sourced from the real daily summary.

Live chip unaffected. The “Current” chip in the page header continues to be powered by NOAA Aviation Weather's live METAR feed (a separate path from the historical observations) and is unchanged. The Raw METAR tooltip is also unchanged.

The dashboard's Weather & Operations summary card was also updated to use the real hourly wind direction at each operation's hour for the “X winds dominant” subtitle, replacing the deterministic estimated wind direction the card previously used.

The “Show Noise Footprint” feature on individual flight details applied no unit conversion to FlightAware altitude data, producing dB values 11 to 16 dB higher than reality at typical cruise altitudes. A named helper at the boundary plus a cross-check test prevent recurrence.

The Weather Correlation Analysis card on the /weather page (Wind Speed vs Noise Level, Temperature vs Operations, Operations by Weather Condition, Wind Rose, and Key Insights) uses deterministic estimated weather for the selected period rather than observed historical NOAA data. The page header subtitle, the page-bottom source line, and the About page Data Sources entry previously implied the analysis used NOAA observations. Those claims have been replaced with honest disclosure: an inline notice on the correlation card identifies the data as estimated, the page header subtitle and source line describe each data path accurately, and the About page methodology subsections each note the estimated-weather provenance.

The live current-conditions chip in the WeatherCorrelation card header continues to use real NOAA METAR data and is unaffected. The Raw METAR tooltip continues to use real NOAA METAR data and is unaffected. The Estimated Carbon Emissions block uses a separate data path (FlightAware operations and ICAO emission factors) and is unaffected.

The Key Insights section now requires a minimum of 10 days per subset for any percentage-difference insight, and uses descriptive rather than causal language. Insights below the threshold are suppressed.

Verified historical-NOAA ingestion is planned. When implemented, the correlation analysis will use real observed weather and the disclosure language will be retired.

JPXWatch's various noise-modeling surfaces previously used inconsistent ground elevation defaults: the live noise trail visualization used 30 feet (a regional average for the South Fork coastal plain), while the footprint calculator, DNL grid pipeline, and altitude-compliance checks all used 55 feet (the airport field elevation per FAA Form 5010). The trail visualization has been updated to use the same 55-foot baseline as the rest of the pipeline, and to apply the same location-specific elevation overrides for characterized higher-elevation zones (currently the South Fork moraine ridge near Town Line Road in Wainscott, 132.5 feet MSL).

Impact on published values. Trail-visualized noise estimates increase by approximately 0.5 dB over baseline-terrain locations and by approximately 1.5 dB over moraine-override zones, reflecting more accurate AGL calculations. The DNL grid pipeline, footprint calculator, and other modeling surfaces are unaffected — they already used the 55-foot baseline and (for the DNL grid) location-specific overrides.

Planned improvements include extending location-specific elevation data to additional flight-path-sensitive areas (East Hampton proper, Sagaponack, North Fork analogs) and eventually integrating per-location terrain data from the USGS National Elevation Dataset.

JPXWatch's noise-estimation pipeline was updated to use track-derived event exposure duration and atmospheric absorption in the DNL grid pipeline.

Track-derived exposure. Sound Exposure Level (SEL) is now estimated using the time an aircraft spent within the listener's noise-impact radius, derived from FlightAware track data, rather than a fixed 15-second flyover default. For events with multiple track points within the radius, exposure is calculated from the observed track-point span plus a 30-second nominal interval; single-point events receive a 30-second nominal duration.

Atmospheric absorption. The model now applies a static atmospheric absorption adjustment as a simple linear function of total slant distance, approximately 0.5 dB per 1,000 feet. This adjustment was previously implemented but not applied to DNL grid calculations.

Lateral attenuation deferred. Lateral attenuation remains gated off in the live DNL grid pending a separate methodology review. The open questions are the provenance of the simplified attenuation table and the angle convention used by the lookup. This work is deferred pending external expert engagement.

Impact on published values. Estimated seasonal DNL values across the KJPX impact zone increased by approximately +1.8 dB at the median, with a mean increase of +2.15 dB across 335,016 grid cells. Grid cells modeled at or above 65 dB seasonal DNL-style exposure increased from 10 to 83. This increase is concentrated near the airport and appears to be driven primarily by the track-derived exposure-duration change at short slant distances, where atmospheric absorption is comparatively small. These values remain modeled estimates, not monitor measurements or formal Part 150 contours.

Documentation reconciliation. Public methodology documentation was updated to reflect the current live model. The About page now describes JPXWatch as a first-order source-propagation model informed by aviation-noise modeling principles, not as an AEDT implementation or regulatory contour model. The heatmap language was also revised to refer to the FAA Part 150 reference threshold, rather than implying that JPXWatch's seasonal-DNL estimates are equivalent to formal annual Part 150 contours.

This revision was implemented in three phases (A0, A1a, A1b) over April 2026, addressing inconsistencies in how the dashboard labeled aircraft noise values across surfaces.

Background. Aircraft noise certification under FAA/EASA Part 36 uses different units depending on aircraft category. Small fixed-wing aircraft (Appendix F, G) and small helicopters (Appendix J) are certified in A-weighted decibels (dB(A)). Jets (Appendix B) and heavy helicopters (Appendix H) are certified in Effective Perceived Noise Level (EPNdB), which accounts for the tonal character and duration of jet noise. JPXWatch's dashboard aggregates noise data across all aircraft categories. Prior to April 2026, the dashboard inconsistently labeled aggregated values as “dB(A)” — technically incorrect for the EPNdB-derived portions of the data.

A0 (April 2026 — PR 195). Per-flight value displays, tooltips, alert messages, CSV exports, and Mapbox text fields were updated to use unit-neutral labels (plain “dB” rather than “dB(A)”) in mixed-fleet aggregation contexts. The unit-neutral approach reflects that aggregated values combine measurements derived from different certification units and cannot be assigned to a single weighting convention.

A1a (April 2026 — PR 196). Five band legends across the dashboard (Aircraft Type Breakdown, Map Overlays Flight Density, Map Overlays Live noise trails, Today Hero Map compact, Weather Correlation wind rose) were unified to a four-band scheme: < 65 dB Quiet, 65–74 dB Moderate, 75–84 dB Loud, ≥ 85 dB Very Loud. A shared utility (lib/noise/bands.ts) was introduced to centralize the band definitions and color tokens. The DNL legend on the Noise Exposure Map was not changed — it uses FAA Part 150 land-use compatibility categories, which are appropriately distinct from the perceptual bands.

A1b (April 2026 — this revision). The About page methodology section was updated to describe the unit-convention approach explicitly. Several factual claims were corrected:

• AEDT NPD methodology is documented in Section 4.2 of the AEDT 4a Technical Manual, not Section 11.3.4 (which covers BADA 4 aircraft performance, not noise). The previous citation was incorrect.
• The seasonal-airport DNL passage was rewritten to argue from the underlying mathematics (averaging dilutes individual loud events at low traffic volumes) rather than from a specific JFK operations figure that was not directly verifiable.
• The High-Noise Events methodology in the My Home feature was repositioned as provisional pending methodology review. The previous framing conflated single-event modeled noise at a listener address with FAA Part 150's 65 dB DNL cumulative threshold; these share a number but measure different acoustic quantities. Refining the threshold value and its acoustic basis is a planned methodology task.

A1b also extended the unit-convention work to aircraft cards on the /seaplanes, /helicopters, and /jets pages. Each aircraft card's modeled-takeoff stat block now displays the unit that matches the data the dashboard carries: EPNdB for jets (computed from Part 36 Appendix B EPNdB cert readings); dB(A) for helicopters and small fixed-wing (data is LAmax at 1,000 ft, an A-weighted measurement, either field-measured via FAA ROSAP technical reports or converted from cert EPNdB).

AEDT subsetting detail. JPXWatch's current calculation — Part 36 reference noise plus inverse-square geometric spreading plus a linear approximation of atmospheric absorption — is a defensible subset of AEDT 4a methodology. Three specific AEDT adjustments are not yet implemented:

• Noise Fraction Adjustment (AEDT §4.3.3): accounts for the fraction of the flight path contributing to noise at a given listener location.
• Duration Adjustment (AEDT §4.3.4): accounts for variation in event duration relative to the reference duration used in NPD curves.
• Lateral Attenuation Adjustment (AEDT §4.3.5): accounts for ground-effect attenuation at lateral distances from the flight path.

Implementation of these adjustments is tracked as a planned improvement, awaiting expert review of how to subset AEDT methodology appropriately for KJPX's small-airport operating profile. Two AEDT-acknowledged limitations are inherited by JPXWatch's modeling and are documented on the About page (Section 11): under-prediction over acoustically hard surfaces such as water, and the inability to separately account for airframe noise as distinct from propulsion noise.

Renamed user-facing “Curfew Violations” to “Curfew Operations,” and “Curfew Violators” / “Repeat Offenders” to “Curfew Operators” / “Repeat Curfew Operators,” across the main dashboard, mobile app, analytics surfaces, narrative insights, alert display labels, and CSV exports. The rename aligns short-form UI labels with the descriptive framing already in use on this page and in the Grading Formula: the dashboard reports observed operations during the Town's published 10 PM – 7 AM curfew, not formal regulatory findings.

The word “violation” is retained where it refers to formal regulatory findings rather than dashboard metrics — specifically, in the operator scorecard disclaimer that distinguishes project-defined community transparency metrics from FAA regulatory determinations, and in the About-page parenthetical characterizing what the site's data is not (legal evidence of route violations; the published routes are voluntary procedures, not regulatory mandates). Those uses are legally precise and deliberate.

No metric, calculation, or filter behavior changed. String-literal alert-rule trigger types and internal identifiers / API field names are deferred to a subsequent migration so that saved alert rules continue to work.

The corrections log section of the About page was migrated to a standalone page at /about/revisions and renamed “Methodology & Data Revisions” to distinguish it from the existing /corrections submission portal. All prior entries are retained with identical substantive content; changes are limited to headline formatting, impact tagging, ordering, and the addition of the “About this log” preamble and “Summary of material changes” section. No entries were removed, softened, or materially revised.

Scorecard methodology and labels. Refined the scorecard methodology and supporting terminology. The “Event level” column replaces the previous “Est. dB” header; “high-noise” replaces “loud” throughout. The numerical compliance score is no longer displayed on scorecards; only the letter grade appears. The underlying scoring formula and grade bands are documented in the scorecard methodology section.

Noise estimation fallback logic. The site's fallback logic for aircraft types not in the type-specific certification mapping now routes through a category-average path (helicopter, jet, or fixed-wing) rather than a single generic default. This matches the fallback approach described in the methodology section and produces more accurate estimates for a wider set of aircraft. Existing records have been updated to reflect the new logic.

Basis-of-estimate indicator. Each operator scorecard now displays a small indicator next to the Event level showing whether the value is derived from type-specific certification data, a category average, or a generic fallback. The indicator and its explanatory legend make the provenance of each value visible at a glance.

Expanded type-specific mapping. Additional aircraft types observed at KJPX have been added to the type-specific noise profile mapping, with values sourced from FAA and EASA Part 36 certification data. This moves the noise estimates for these types from category-average derivation to values specific to their aircraft type.

Within-type variation disclosure. The About page's noise methodology section now includes a subsection on within-type variation, acknowledging that aircraft sharing an ICAO type code can produce different real-world noise depending on generation, configuration, modifications, and operating technique.

Flights filed to arrive at KJPX but diverted to another airport before landing are no longer counted as KJPX operations in public totals. This aligns with the physical-presence methodology already stated for outbound diversions: only aircraft that actually touched the KJPX runway are counted. Inbound-diverted flights are retained in the database for transparency (operator patterns, weather-related diversion clusters), and FlightAware applies the same convention on its airport pages.

Five genuinely-missing operations were recovered and added to the public record. Two transient webhook-ingestion bugs caused 39 flight events to fail during two narrow windows: 27 on April 8 (null-status constraint) and 12 between April 11 and April 13 (status-check constraint). Most of the affected flights were already captured by the next-morning batch pull from FlightAware's history API, so the operational record was never substantially incomplete. Replaying the dead-letter queue restored 5 genuinely-missing operations (N9934Q local-circuit training loops at KJPX on the afternoon of April 8).

As part of this work, a latent issue was also corrected: out-of-order webhook events could previously overwrite populated flight fields with null values. Flight records are now merged rather than replaced on re-ingest.

198 flights (1.13% of the 17,453 flights in the database with full ADS-B track data) were tagged as KJPX operations by FlightAware but never came within 4 nautical miles of the airport. These phantom operations are concentrated in two operators (Cutter Aviation and NetJets, approximately 65% combined) and are predominantly fixed-wing and jet rather than helicopter. The phantom rate has declined over time, from 5–14% in 2020 to under 1% in recent months, reflecting improvements in upstream data quality.

Going forward, every newly ingested operation is cross-checked against ADS-B position data. Operations whose closest approach to KJPX (40.9594°N, 72.2518°W) exceeds 4 nautical miles are flagged for review and excluded from public counts. The 4 nm threshold was set after sampling 25 borderline flights and finding a clean break: every flight whose closest approach was within 3.75 nm was a verified KJPX operation, and every flight at 4.33 nm or greater was a phantom.

Approximately 85% of historical operations come from earlier batch imports without ADS-B track data and cannot be retroactively verified by this method. Historical counts remain as originally recorded; year-over-year comparisons should account for the fact that data from this point forward is more rigorously verified.

JPXWatch now compares the filed destination on a flight's departure record against the actual landing destination on its arrival record. When the two differ, the flight is flagged as diverted and a “Diverted” badge appears in the operations table and flight detail view, matching the treatment in FlightAware's app. Diverted flights remain counted as KJPX departures (the aircraft did physically depart KJPX), but the badge gives a complete picture of the flight's outcome. A historical backfill identified one prior diversion in the database.

A trigger on the ADS-B position table had an incorrect search path and was silently rolling back point insertions for a subset of flights, leaving 337 flights without denormalized track data. The trigger has been corrected and the affected flights backfilled.

A methodology audit identified that the approach-phase noise offset for helicopter arrivals was being applied in a direction inconsistent with the underlying source data. The offset has been corrected. Approach-phase modeled estimates, which primarily affect helicopter arrival operations, now reflect the corrected calculation.

The underlying source measurement (lamax at 1,000 ft from FAA technical reports) is a flyover measurement; the approach value is derived by applying a −2 dB offset consistent with the EASA-derived convention used for all other aircraft types in the model. Details in the investigation report and methodology audit.

Helicopter noise estimates decreased by 1–5 dB depending on type; the C56X (Citation XLS+) decreased by 2 dB; 19 previously-unrecognized aircraft types now receive per-type estimates instead of a generic 80 dB fallback. JPXWatch previously maintained two independent noise lookup tables — a 28-type client-side table and a 47-type EASA-derived mapping — and different views (e.g., live noise trails vs. track-based analysis) could produce different dB estimates for the same aircraft type. This inconsistency has been eliminated.

All code paths now use a single lookup cascade: FAA field-measured data (where available for helicopters) → EASA certification data (47 types) → category-average fallback.

For 9 common helicopter types (R22, R44, R66, S76, EC35, A109, B06, B407, AS50), source noise levels now come from FAA technical reports containing actual ground-level measurements at 1,000 ft (DOT/FAA/CT-84-2, FAA-AEE-01-04, FAA-AEE-09-01, FAA-AEE-15-01). Measured values are lower than the prior certification-derived estimates.

For the C56X, takeoff decreased from 86 to 84 dB and approach from 82 to 80 dB, adopting the EASA certification value (84/80) over the prior un-sourced estimate.

Nineteen additional aircraft types (including S92, GLF6, CL30, CL35, CL60, C750, B350, and others) now receive per-type estimates; most are louder than the generic 80 dB default they previously received.

Two related changes to the Noise Impact Score:

Loud-jet correction. Historical Noise Impact Scores previously treated all jets as ≥85 dB in the Fleet Mix component because per-flight noise estimates were not preserved in monthly aggregates. JPXWatch now stores a per-day “loud jets” count in the daily summary table, populated from the same per-flight estimation pipeline used elsewhere on the site. Historical scores have been recomputed under the corrected methodology and may show modestly lower Fleet Mix subscores than previously published, particularly for periods with significant light-jet traffic.

SEVERE tier boundary adjusted. The SEVERE tier boundary moved from ≥80 to ≥85, narrowing the top tier to be more selective and better match the underlying score distribution. The HIGH tier now covers 65–84. This change applies prospectively and to historical period displays as scores are re-rendered.

The public corrections log is now live, providing a structured public channel for submitting and evaluating specific corrections to data points, classifications, methodology, and operator identity claims. All submissions and their resolutions are documented transparently. Accepted curfew-period exceptions (e.g., mechanical diversions, medical emergencies) are excluded from grading-formula penalties.

No changes to calculations, data sources, or displayed values; this update improves how the methodology is described.

Added explicit description of the regulatory pedigree linking Part 36 certification data to the FAA's AEDT, ICAO Doc 9911, and the Aircraft Noise and Performance database. Corrected the description of certification measurement geometry (three reference points per Part 36, not a single reference distance).

Added peer-reviewed validation citations: Rindfleisch et al. (2024, JASA) large-scale AEDT validation at SFO; Meister et al. (2021, Aerospace) three-model comparison at Zurich and Geneva; Simons et al. (2022) on certification-category correlation with measured noise trends at Schiphol.

Added comparative context noting other airport noise platforms (WebTrak, Casper, Noise-Map.com) that use the same aircraft-type-based methodology. Added “relative vs. absolute” framing clarifying that JPXWatch's primary analytical value is comparative ranking of aircraft types and operators, not precise decibel certification at specific locations.

Added prominent disclaimer that displayed decibel values are modeled estimates derived from type-certification data rather than on-site sound measurements.

Renamed glossary term “Repeat Offender” to “Repeat Curfew-Period Operator” to better match the project's framing of curfew operations as observed events against a published standard rather than legal violations.

Expanded the operator scorecard disclaimer to explicitly note that grades are not judgments about safety, legality, service quality, or overall company performance.

Softened narrative language about “gap between voluntary commitments and actual behavior” to “differences between published standards, voluntary commitments, and observed operations” to align tone with the project's measurement framing.

Renamed “Curfew violations” to “Curfew-period operations” within the Grading Formula to align terminology with the project's framing of curfew operations as observed events against the Town's published standard rather than legal violations.

Expanded the Compliance Grading Note to explicitly state that grades are not judgments about safety, legality, service quality, or overall company performance, bringing the About page Note into parity with the corresponding disclaimer on operator scorecards.

Replaced undefined uses of “accountability” with “scorecards” or “transparency metrics” in navigation, section headers, and narrative framing. This change does not affect any metric, calculation, or data display — it aligns framing language with the project's measurement-and-documentation stance rather than an adversarial one. Defined terms of art (“compliance grade,” “compliance rate”) are unchanged, as these are mechanically computed against the Town of East Hampton's published 10 PM – 7 AM curfew standard.