Let a weather source describe its own products

A weather source can describe its own products (credit, units, coverage, legend) through an optional `display` object in each product manifest: source, credit, units, coverage, info, legend and extent. The weather layer uses each valid field in the row summary, legend, info text, coverage navigation, outside-coverage status, layer stats and imagery credit, and keeps today's built-in value for any field that is absent or invalid. Units and legend describe one scale, so they apply only as a valid pair; otherwise both keep their built-in values, and the radar info heading names the units in use. Text is single-line and length-capped. It rejects control characters (U+0000-U+001F, U+007F-U+009F), line and paragraph separators, and invisible or format characters: soft hyphen (U+00AD), combining grapheme joiner (U+034F), Arabic letter mark (U+061C), Mongolian vowel separator (U+180E), zero-width and direction marks (U+200B-U+200F), bidi embedding and override (U+202A-U+202E), word joiner, invisible operators and bidi isolates (U+2060-U+2069), variation selectors (U+FE00-U+FE0F), the byte-order mark (U+FEFF) and tag characters (U+E0000-U+E007F). Legends need 2-16 stops whose labels are plain decimal numbers or short text and whose colours are #rrggbb. A number label must read back exactly as the legend shows it: within the safe integer range, with no leading zeros and no digits lost to rounding. Extents must be finite, in range and non-empty. Supplied source and units text is data: the layer marks it so the panels show it untranslated, while built-in values are translated as before. The imagery credit is escaped as plain text and follows a refreshed manifest even when the shown frame stays the same. A refresh changes only the credit: the shown frame keeps the snapshot it was staged from, so a later host switch restages it with its own time and bounds and the refreshed credit. Manifests without `display`, including the bundled nowCOAST ones, render exactly as before.
2026-11-04 02:14:01 +00:00 · 2026-10-31 22:42:01 -07:00
1 parent 3cd7d0fe15
commit 039b0828b7
@@ -1759,6 +1759,8 @@
  "Contiguous US · gaps ≠ no rain": "USA ohne Alaska/Hawaii · Lücken ≠ kein Regen",
  "Americas + Pacific · not individual strikes": "Amerika + Pazifik · keine Einzelblitze",
  "Color: strikes/km²/min ×10³": "Farbe: Blitze/km²/min ×10³",
+  "Color: {units}": "Farbe: {units}",
+  "RADAR · {units}": "RADAR · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · meist 2–3 h verzögert",
  "North America · infrared imagery": "Nordamerika · Infrarotbilder",
  "Reduced motion · history playback unavailable": "Reduzierte Bewegung · Verlaufswiedergabe nicht verfügbar",
@@ -1260,6 +1260,8 @@
  "Contiguous US · gaps ≠ no rain": "EE. UU. contiguos · huecos ≠ sin lluvia",
  "Americas + Pacific · not individual strikes": "América + Pacífico · no son rayos individuales",
  "Color: strikes/km²/min ×10³": "Color: rayos/km²/min ×10³",
+  "Color: {units}": "Color: {units}",
+  "RADAR · {units}": "RADAR · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · normalmente con 2–3 h de retraso",
  "North America · infrared imagery": "Norteamérica · imágenes infrarrojas",
  "Reduced motion · history playback unavailable": "Movimiento reducido · reproducción del historial no disponible",
@@ -1214,6 +1214,8 @@
  "Contiguous US · gaps ≠ no rain": "États-Unis contigus · lacunes ≠ absence de pluie",
  "Americas + Pacific · not individual strikes": "Amériques + Pacifique · pas des impacts individuels",
  "Color: strikes/km²/min ×10³": "Couleur : impacts/km²/min ×10³",
+  "Color: {units}": "Couleur : {units}",
+  "RADAR · {units}": "RADAR · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · retard habituel de 2 à 3 h",
  "North America · infrared imagery": "Amérique du Nord · imagerie infrarouge",
  "Reduced motion · history playback unavailable": "Animations réduites · lecture de l'historique indisponible",
@@ -1214,6 +1214,8 @@
  "Contiguous US · gaps ≠ no rain": "USA contigui · lacune ≠ assenza di pioggia",
  "Americas + Pacific · not individual strikes": "Americhe + Pacifico · non singoli fulmini",
  "Color: strikes/km²/min ×10³": "Colore: fulmini/km²/min ×10³",
+  "Color: {units}": "Colore: {units}",
+  "RADAR · {units}": "RADAR · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · di solito 2–3 h di ritardo",
  "North America · infrared imagery": "Nord America · immagini all'infrarosso",
  "Reduced motion · history playback unavailable": "Movimento ridotto · riproduzione dello storico non disponibile",
@@ -1182,6 +1182,8 @@
  "Contiguous US · gaps ≠ no rain": "米国本土 · 欠測 ≠ 降水なし",
  "Americas + Pacific · not individual strikes": "南北アメリカ + 太平洋 · 個々の落雷ではありません",
  "Color: strikes/km²/min ×10³": "色：落雷数/km²/分 ×10³",
+  "Color: {units}": "色：{units}",
+  "RADAR · {units}": "レーダー · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · 通常2–3時間遅れ",
  "North America · infrared imagery": "北米 · 赤外画像",
  "Reduced motion · history playback unavailable": "動きを減らす設定 · 履歴再生は利用不可",
@@ -1212,6 +1212,8 @@
  "Contiguous US · gaps ≠ no rain": "EUA contíguos · lacunas ≠ sem chuva",
  "Americas + Pacific · not individual strikes": "Américas + Pacífico · não são raios individuais",
  "Color: strikes/km²/min ×10³": "Cor: raios/km²/min ×10³",
+  "Color: {units}": "Cor: {units}",
+  "RADAR · {units}": "RADAR · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · normalmente com 2–3 h de atraso",
  "North America · infrared imagery": "América do Norte · imagens infravermelhas",
  "Reduced motion · history playback unavailable": "Movimento reduzido · reprodução do histórico indisponível",
@@ -1278,6 +1278,8 @@
  "Contiguous US · gaps ≠ no rain": "Континентальные США · пробелы ≠ нет дождя",
  "Americas + Pacific · not individual strikes": "Америка + Тихий океан · не отдельные разряды",
  "Color: strikes/km²/min ×10³": "Цвет: разрядов/км²/мин ×10³",
+  "Color: {units}": "Цвет: {units}",
+  "RADAR · {units}": "РАДАР · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60° ю. ш.–60° с. ш. · обычно задержка 2–3 ч",
  "North America · infrared imagery": "Северная Америка · ИК-снимки",
  "Reduced motion · history playback unavailable": "Уменьшение движения · воспроизведение истории недоступно",
@@ -1229,6 +1229,8 @@
  "Contiguous US · gaps ≠ no rain": "48 суміжних штатів США · прогалини ≠ немає дощу",
  "Americas + Pacific · not individual strikes": "Америка + Тихий океан · не окремі розряди",
  "Color: strikes/km²/min ×10³": "Колір: розрядів/км²/хв ×10³",
+  "Color: {units}": "Колір: {units}",
+  "RADAR · {units}": "РАДАР · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60° пд. ш.–60° пн. ш. · зазвичай затримка 2–3 год",
  "North America · infrared imagery": "Північна Америка · ІЧ-знімки",
  "Reduced motion · history playback unavailable": "Зменшення руху · відтворення історії недоступне",
@@ -1156,6 +1156,8 @@
  "Contiguous US · gaps ≠ no rain": "美国本土 · 数据缺失 ≠ 无降雨",
  "Americas + Pacific · not individual strikes": "美洲与太平洋 · 非单次闪击",
  "Color: strikes/km²/min ×10³": "颜色：闪击次数/km²/分钟 ×10³",
+  "Color: {units}": "颜色：{units}",
+  "RADAR · {units}": "雷达 · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · 通常延迟 2–3 小时",
  "North America · infrared imagery": "北美洲 · 红外影像",
  "Reduced motion · history playback unavailable": "减弱动效 · 历史回放不可用",
@@ -1151,6 +1151,8 @@
  "Contiguous US · gaps ≠ no rain": "美國本土 · 數據缺失 ≠ 無降雨",
  "Americas + Pacific · not individual strikes": "美洲與太平洋 · 非單次閃擊",
  "Color: strikes/km²/min ×10³": "顏色：閃擊次數/km²/分鐘 ×10³",
+  "Color: {units}": "顏色：{units}",
+  "RADAR · {units}": "雷達 · {units}",
  "60°S–60°N · typically 2–3 h delayed": "60°S–60°N · 通常延遲 2–3 小時",
  "North America · infrared imagery": "北美洲 · 紅外影像",
  "Reduced motion · history playback unavailable": "減弱動效 · 歷史回放不可用",
@@ -93,6 +93,7 @@
    "Plan",
    "Pop",
    "Punk",
+    "RADAR · {units}",
    "RADIO",
    "REC",
    "REGION",
@@ -184,6 +185,7 @@
    "CCTV",
    "CRS {value}°",
    "CRT",
+    "Color: {units}",
    "Country",
    "DEST ---°",
    "DEST {bearing}",
@@ -235,6 +237,7 @@
    "Pop",
    "Punk",
    "R&B",
+    "RADAR · {units}",
    "RADIO",
    "RANGE",
    "REC",
@@ -400,6 +403,7 @@
    "Plan",
    "Pop",
    "Punk",
+    "RADAR · {units}",
    "RADIO",
    "REC",
    "Radio",
@@ -562,6 +566,7 @@
    "PRECIP",
    "Pop",
    "Punk",
+    "RADAR · {units}",
    "RADIO",
    "REC",
    "RESET",
@@ -765,6 +770,7 @@
    "Paris",
    "Pop",
    "Punk",
+    "RADAR · {units}",
    "RANGE",
    "REC",
    "Reggae",
@@ -0,0 +1,153 @@
+/**
+ * A weather source can describe its own products (credit, units, coverage,
+ * legend) in the optional `display` object of a product manifest. Each field
+ * is checked on its own: an absent or invalid field is dropped, and the layer
+ * keeps its built-in text for it. Units and legend describe the same scale,
+ * so they are kept only together. Accepted text is source data, shown as is
+ * rather than translated.
+ */
+
+const TEXT_LIMITS = Object.freeze({
+  source: 60,
+  credit: 200,
+  units: 40,
+  coverage: 48,
+  info: 600,
+});
+const LEGEND_MIN = 2;
+const LEGEND_MAX = 16;
+const LEGEND_LABEL_MAX = 16;
+// Control and line-break characters, plus invisible or format characters:
+// soft hyphen, combining grapheme joiner, Arabic letter mark, Mongolian vowel
+// separator, zero-width, direction-mark, bidi embedding/override/isolate,
+// variation selector, byte-order and tag characters.
+const CONTROL =
+  /[\u0000-\u001f\u007f-\u009f\u00ad\u034f\u061c\u180e\u200b-\u200f\u2028-\u202e\u2060-\u2069\ufe00-\ufe0f\ufeff\u{e0000}-\u{e007f}]/u;
+// A number label must read as a plain decimal, as the legend formats it.
+const DECIMAL = /^-?\d+(?:\.\d+)?$/;
+// A label the legend formats as a number: a plain decimal, maybe with "+".
+const SCALE_NUMBER = /^-?(\d+(?:\.(\d+))?)\+?$/;
+const COLOR = /^#[0-9a-f]{6}$/i;
+const EMPTY = Object.freeze({});
+const cache = new WeakMap();
+
+function text(value, max) {
+  if (typeof value !== 'string') return undefined;
+  const trimmed = value.trim();
+  return trimmed && trimmed.length <= max && !CONTROL.test(trimmed)
+    ? trimmed
+    : undefined;
+}
+
+/**
+ * Whether a label the legend formats as a number reads back exactly as given:
+ * within the safe integer range and with no digits lost to rounding, so
+ * '9999999999999999' (shown as 10000000000000000) and '007' are refused.
+ * Other text is shown as given.
+ */
+function exactScaleLabel(label) {
+  const match = SCALE_NUMBER.exec(label);
+  if (!match) return true;
+  const magnitude = Number(match[1]);
+  return (
+    magnitude <= Number.MAX_SAFE_INTEGER &&
+    magnitude.toFixed(match[2]?.length ?? 0) === match[1]
+  );
+}
+
+function number(value) {
+  if (!Number.isFinite(value)) return undefined;
+  const label = String(value);
+  return DECIMAL.test(label) && label.length <= LEGEND_LABEL_MAX
+    ? label
+    : undefined;
+}
+
+function legend(value) {
+  if (
+    !Array.isArray(value) ||
+    value.length < LEGEND_MIN ||
+    value.length > LEGEND_MAX
+  )
+    return undefined;
+  const stops = [];
+  for (const stop of value) {
+    if (!stop || typeof stop !== 'object') return undefined;
+    const label =
+      typeof stop.label === 'number'
+        ? number(stop.label)
+        : text(stop.label, LEGEND_LABEL_MAX);
+    if (label === undefined || !exactScaleLabel(label)) return undefined;
+    if (typeof stop.color !== 'string' || !COLOR.test(stop.color))
+      return undefined;
+    stops.push(Object.freeze([label, stop.color]));
+  }
+  return Object.freeze(stops);
+}
+
+function extent(value) {
+  if (!value || typeof value !== 'object') return undefined;
+  const { west, south, east, north } = value;
+  if (
+    ![west, south, east, north].every(Number.isFinite) ||
+    west < -180 ||
+    west > 180 ||
+    east < -180 ||
+    east > 180 ||
+    south < -90 ||
+    north > 90 ||
+    south >= north ||
+    // No width: one meridian, including 180 to -180 across the antimeridian.
+    west === east ||
+    west - east >= 360
+  )
+    return undefined;
+  // West greater than east crosses the antimeridian.
+  return Object.freeze({ west, south, east, north });
+}
+
+/**
+ * The valid display fields of a weather manifest; `{}` when it has none.
+ * @param {object|null|undefined} manifest A validated weather snapshot.
+ * @returns {{ source?: string, credit?: string, units?: string,
+ *   coverage?: string, info?: string,
+ *   legend?: ReadonlyArray<readonly [string, string]>,
+ *   extent?: { west: number, south: number, east: number, north: number } }}
+ */
+export function weatherDisplay(manifest) {
+  const display = manifest?.display;
+  if (!display || typeof display !== 'object' || Array.isArray(display))
+    return EMPTY;
+  const known = cache.get(manifest);
+  if (known) return known;
+  const result = {};
+  for (const [key, max] of Object.entries(TEXT_LIMITS)) {
+    const value = text(display[key], max);
+    if (value !== undefined) result[key] = value;
+  }
+  const stops = legend(display.legend);
+  if (stops && result.units !== undefined) result.legend = stops;
+  else delete result.units;
+  const box = extent(display.extent);
+  if (box) result.extent = box;
+  Object.freeze(result);
+  cache.set(manifest, result);
+  return result;
+}
+
+/** Whether a longitude/latitude falls inside an extent, across the antimeridian too. */
+export function insideExtent({ west, south, east, north }, lon, lat) {
+  if (lat < south || lat > north) return false;
+  return west < east ? lon >= west && lon <= east : lon >= west || lon <= east;
+}
+
+/** Plain text for a Cesium credit, which otherwise reads its text as HTML. */
+export function escapeCreditText(value) {
+  return value.replace(
+    /[&<>"']/g,
+    (ch) =>
+      ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' })[
+        ch
+      ],
+  );
+}
@@ -0,0 +1,839 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import * as Cesium from 'cesium';
+import { GeographicTilingScheme } from 'cesium';
+import { createWeatherLayer } from './index.js';
+import { createWeatherRendering } from './rendering.js';
+import { weatherDisplay, insideExtent, escapeCreditText } from './display.js';
+import { createShellCesium, createShellScene } from './shellFixture.mjs';
+import { formatScaleLabel } from '../../ui/unitLabels.js';
+
+const times = ['2026-09-15T20:00:00.000Z', '2026-09-15T20:05:00.000Z'];
+const base = {
+  schemaVersion: 1,
+  times,
+  latest: times[1],
+  bounds: { west: -180, south: -60, east: 180, north: 80 },
+};
+const flush = async () => {
+  for (let i = 0; i < 30; i++) await Promise.resolve();
+};
+const quiet = () => ({
+  matches: false,
+  hidden: false,
+  addEventListener() {},
+  removeEventListener() {},
+});
+
+/**
+ * A layer whose renderer shows every requested frame at once. `center` is the
+ * map centre as [lon, lat]; `manifests` maps a product to its manifest, and
+ * may be changed between updates.
+ */
+async function shownLayer(id, manifest, params, view = {}) {
+  let time = null;
+  const flights = [];
+  const snapshots = [];
+  const manifests = { [manifest.product]: manifest };
+  const layer = createWeatherLayer({
+    id,
+    feed: { getSnapshot: async ({ product }) => manifests[product] },
+    documentRef: quiet(),
+    eventTarget: quiet(),
+    matchMedia: () => quiet(),
+    createRendering: () => ({
+      rehome() {},
+      setAlpha() {},
+      setHidden() {},
+      updateSnapshot(snapshot) {
+        snapshots.push(snapshot);
+      },
+      async setFrame(_snapshot, selected) {
+        time = selected;
+        return true;
+      },
+      clear() {
+        time = null;
+      },
+      getDiagnostics: () => ({ time, loading: false, error: null }),
+    }),
+  });
+  layer.init({
+    camera: {
+      moveEnd: { addEventListener: () => () => {} },
+      flyTo: ({ destination }) => flights.push(destination),
+      pickEllipsoid: () =>
+        view.center ? Cesium.Cartesian3.fromDegrees(...view.center) : undefined,
+    },
+    scene: {
+      canvas: { clientWidth: 800, clientHeight: 600 },
+      globe: { ellipsoid: Cesium.Ellipsoid.WGS84 },
+    },
+  });
+  if (params) layer.setParams(params);
+  layer.enable();
+  await layer.update();
+  await flush();
+  layer.attachShellServices({ runNavigation: (navigate) => navigate() });
+  return { layer, flights, manifests, snapshots };
+}
+
+const PRODUCTS = [
+  ['weather-radar', 'radar', undefined],
+  ['weather-lightning', 'lightning', undefined],
+  ['weather-satellite', 'clouds-regional', undefined],
+  ['weather-satellite', 'clouds', { product: 'clouds' }],
+];
+const INVALID = {
+  source: 42,
+  credit: '',
+  units: 'x'.repeat(41),
+  coverage: 'line one\nline two',
+  info: ['not', 'text'],
+  legend: [
+    { label: '1', color: '#ffffff' },
+    { label: '2', color: 'red' },
+  ],
+  extent: { west: 0, south: 10, east: 20, north: 5 },
+};
+
+const SATELLITE_TITLE =
+  'GOES-19/18 longwave infrared Band 14 regional; NESDIS global longwave mosaic. Clouds only dims everything but bright, cold cloud tops; a brightness filter, not a cloud mask. Coverage and freshness differ by region.';
+const SATELLITE_CREDIT =
+  'NOAA nowCOAST · NESDIS GOES / global satellite partners';
+// Today's built-in description of each product, written out rather than
+// derived from the code under test.
+const BUILT_IN = {
+  radar: {
+    units: 'dBZ',
+    coverage: 'CONUS',
+    legend: [
+      ['10', '#00ecec'],
+      ['20', '#0000f6'],
+      ['30', '#00c800'],
+      ['40', '#ffff00'],
+      ['50', '#ff9000'],
+      ['60', '#dc0000'],
+      ['70', '#ff00ff'],
+      ['80', '#05ede0'],
+    ].map(([label, color]) => ({
+      label,
+      color,
+      blurb: `${label} dBZ radar reflectivity`,
+    })),
+    heading: 'RADAR REFLECTIVITY · dBZ',
+    infoCoverage: 'Contiguous US · gaps ≠ no rain',
+    infoTitle:
+      'NOAA MRMS radar echoes indicate precipitation patterns, not rain rate, a storm warning or a future forecast. Native source approximately 1 km; display is limited to level 6. Frames use exact advertised observation times.',
+    chip: 'View US radar',
+    focus: [-180, -60, 180, 80],
+    credit: 'NOAA nowCOAST · NWS/OAR MRMS',
+  },
+  lightning: {
+    units: 'strikes/km²/min ×10³',
+    coverage: 'Americas + Pacific',
+    legend: [
+      ['0.1', '#FFFFCC'],
+      ['1', '#FFA400'],
+      ['5', '#FF4500'],
+      ['10', '#FF0000'],
+      ['50', '#FF00FF'],
+      ['100', '#4000C0'],
+      ['200', '#00C7FF'],
+      ['300+', '#00FF00'],
+    ].map(([label, color]) => ({
+      label,
+      color,
+      blurb: `${label} strikes/km²/min ×10³ (15-minute density)`,
+    })),
+    heading: 'LIGHTNING DENSITY · 15 min accumulation',
+    infoCoverage:
+      'Americas + Pacific · not individual strikes\nColor: strikes/km²/min ×10³',
+    infoTitle:
+      'NOAA/NWS 15-minute lightning density derived from Vaisala NLDN/GLD360. Coverage 110°E across the Pacific/Americas to 0°, 25°S–80°N. Not a live strike count, global coverage or a safety warning.',
+    chip: 'View Americas & Pacific',
+    focus: [110, -25, 0, 80],
+    credit: 'NOAA/NWS lightning density · derived from Vaisala NLDN/GLD360',
+  },
+  'clouds-regional': {
+    units: '',
+    coverage: 'North America',
+    legend: [],
+    heading: 'GOES INFRARED · ~5 min',
+    infoCoverage: 'North America · infrared imagery',
+    infoTitle: SATELLITE_TITLE,
+    chip: 'View coverage',
+    focus: [-180, -60, 180, 80],
+    credit: SATELLITE_CREDIT,
+  },
+  clouds: {
+    units: '',
+    coverage: 'Global · 60°S–60°N',
+    legend: [],
+    heading: 'GLOBAL INFRARED · hourly',
+    infoCoverage: '60°S–60°N · typically 2–3 h delayed',
+    infoTitle: SATELLITE_TITLE,
+    chip: 'View coverage',
+    focus: [-180, -60, 180, 80],
+    credit: SATELLITE_CREDIT,
+  },
+};
+
+/** Assert the built-in description of a product, field by field. */
+function assertBuiltIn(layer, product) {
+  const expected = BUILT_IN[product];
+  const controls = layer.getRowControls();
+  assert.equal(controls.summary.units, expected.units);
+  assert.equal(controls.summary.unitsVerbatim, undefined);
+  assert.equal(controls.summary.coverage, expected.coverage);
+  assert.deepEqual(controls.legend, expected.legend);
+  assert.ok(
+    controls.info.startsWith(`${expected.heading}\n`),
+    `${product} heading: ${controls.info}`,
+  );
+  assert.ok(
+    controls.info.endsWith(`\n${expected.infoCoverage}`),
+    `${product} coverage: ${controls.info}`,
+  );
+  assert.equal(controls.infoTitle, expected.infoTitle);
+  assert.equal(
+    controls.chips.find(({ id }) => id === 'coverage').label,
+    expected.chip,
+  );
+  const stats = layer.getStats();
+  assert.equal(stats.source, 'NOAA nowCOAST');
+  assert.equal(stats.sourceVerbatim, undefined);
+}
+
+for (const [id, product, params] of PRODUCTS) {
+  test(`${product}: a manifest without display metadata keeps today's description`, async (t) => {
+    t.mock.method(Date, 'now', () => Date.parse(times[1]));
+    const { layer, flights } = await shownLayer(
+      id,
+      { ...base, product },
+      params,
+    );
+    assertBuiltIn(layer, product);
+    layer.setParams({ focus: true });
+    assert.deepEqual(
+      flights[0],
+      Cesium.Rectangle.fromDegrees(...BUILT_IN[product].focus),
+    );
+    layer.destroy();
+  });
+}
+
+for (const [id, product, params] of PRODUCTS) {
+  test(`${product}: empty or wholly invalid display metadata changes nothing`, async (t) => {
+    t.mock.method(Date, 'now', () => Date.parse(times[1]));
+    const plain = await shownLayer(id, { ...base, product }, params);
+    const empty = await shownLayer(
+      id,
+      { ...base, product, display: {} },
+      params,
+    );
+    const invalid = await shownLayer(
+      id,
+      { ...base, product, display: INVALID },
+      params,
+    );
+    const expected = plain.layer.getRowControls();
+    assert.deepEqual(empty.layer.getRowControls(), expected);
+    assert.deepEqual(invalid.layer.getRowControls(), expected);
+    assertBuiltIn(invalid.layer, product);
+    for (const h of [plain, invalid]) h.layer.setParams({ focus: true });
+    assert.deepEqual(invalid.flights, plain.flights);
+    for (const h of [plain, empty, invalid]) h.layer.destroy();
+  });
+}
+
+const EXAMPLE = {
+  source: 'Example network',
+  credit: 'Example network · flash density',
+  units: 'flashes/km²/min',
+  coverage: '52°S–52°N',
+  info: 'Flash density from an example network. Not a safety warning.',
+  legend: [
+    { label: 0.5, color: '#112233' },
+    { label: '2', color: '#445566' },
+    { label: '8+', color: '#AABBCC' },
+  ],
+  extent: { west: -180, south: -52, east: 180, north: 52 },
+};
+
+test('valid display metadata describes the product in the row, legend and stats', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const { layer, flights } = await shownLayer('weather-lightning', {
+    ...base,
+    product: 'lightning',
+    display: EXAMPLE,
+  });
+  const controls = layer.getRowControls();
+  assert.equal(controls.summary.units, 'flashes/km²/min');
+  assert.equal(controls.summary.unitsVerbatim, true);
+  assert.equal(controls.summary.coverage, '52°S–52°N');
+  assert.deepEqual(controls.legend, [
+    { label: '0.5', color: '#112233', blurb: '0.5 flashes/km²/min' },
+    { label: '2', color: '#445566', blurb: '2 flashes/km²/min' },
+    { label: '8+', color: '#AABBCC', blurb: '8+ flashes/km²/min' },
+  ]);
+  assert.match(controls.info, /^LIGHTNING DENSITY · 15 min accumulation\n/);
+  assert.match(controls.info, /\n52°S–52°N\nColor: flashes\/km²\/min$/);
+  assert.equal(controls.infoTitle, EXAMPLE.info);
+  assert.equal(
+    controls.chips.find(({ id }) => id === 'coverage').label,
+    'View coverage',
+  );
+  const stats = layer.getStats();
+  assert.equal(stats.source, 'Example network');
+  assert.equal(stats.sourceVerbatim, true);
+  layer.setParams({ focus: true });
+  assert.deepEqual(
+    flights[0],
+    Cesium.Rectangle.fromDegrees(-180, -52, 180, 52),
+  );
+  layer.destroy();
+});
+
+test('units and legend apply only as a valid pair', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const legend = [
+    { label: 1, color: '#000000' },
+    { label: 10, color: '#ffffff' },
+  ];
+  for (const [id, product] of [
+    ['weather-lightning', 'lightning'],
+    ['weather-radar', 'radar'],
+  ])
+    for (const display of [
+      { units: 'mm/h' },
+      { legend },
+      { units: 'mm/h', legend: [legend[0]] },
+      { units: 'x'.repeat(41), legend },
+    ]) {
+      const { layer } = await shownLayer(id, { ...base, product, display });
+      assertBuiltIn(layer, product);
+      layer.destroy();
+    }
+  const radar = await shownLayer('weather-radar', {
+    ...base,
+    product: 'radar',
+    display: { coverage: 'Europe', units: 'mm/h', legend },
+  });
+  const controls = radar.layer.getRowControls();
+  assert.equal(controls.summary.coverage, 'Europe');
+  assert.equal(controls.summary.units, 'mm/h');
+  assert.equal(controls.summary.unitsVerbatim, true);
+  assert.deepEqual(controls.legend, [
+    { label: '1', color: '#000000', blurb: '1 mm/h' },
+    { label: '10', color: '#ffffff', blurb: '10 mm/h' },
+  ]);
+  assert.match(controls.info, /^RADAR · mm\/h\n/);
+  assert.match(controls.info, /\nEurope$/);
+  radar.layer.destroy();
+  const clouds = await shownLayer('weather-satellite', {
+    ...base,
+    product: 'clouds-regional',
+    display: {
+      units: 'K',
+      legend: [
+        { label: 'warm', color: '#000000' },
+        { label: 'cold', color: '#ffffff' },
+      ],
+    },
+  });
+  assert.equal(clouds.layer.getRowControls().summary.units, 'K');
+  assert.deepEqual(clouds.layer.getRowControls().legend, [
+    { label: 'warm', color: '#000000', blurb: 'warm K' },
+    { label: 'cold', color: '#ffffff', blurb: 'cold K' },
+  ]);
+  clouds.layer.destroy();
+});
+
+test('other display fields fall back on their own', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const { layer } = await shownLayer('weather-lightning', {
+    ...base,
+    product: 'lightning',
+    display: { ...INVALID, coverage: 'Example coverage', source: 'Example' },
+  });
+  const controls = layer.getRowControls();
+  assert.equal(controls.summary.coverage, 'Example coverage');
+  assert.equal(controls.summary.units, BUILT_IN.lightning.units);
+  assert.deepEqual(controls.legend, BUILT_IN.lightning.legend);
+  assert.equal(controls.infoTitle, BUILT_IN.lightning.infoTitle);
+  assert.equal(layer.getStats().source, 'Example');
+  layer.destroy();
+});
+
+test('the map centre is checked against the source extent when one is given', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const OUTSIDE = 'Map center is outside source coverage';
+  const outside = (layer) => layer.getRowControls().info.includes(OUTSIDE);
+  const at = async (id, product, display, center) => {
+    const h = await shownLayer(
+      id,
+      { ...base, product, ...(display ? { display } : {}) },
+      undefined,
+      { center },
+    );
+    const result = outside(h.layer);
+    if (result)
+      assert.equal(
+        h.layer.getRowControls().summary.status,
+        'Map center outside coverage',
+      );
+    h.layer.destroy();
+    return result;
+  };
+  // Without an extent: the manifest bounds, plus lightning's built-in gap.
+  assert.equal(
+    await at('weather-lightning', 'lightning', null, [50, 10]),
+    true,
+  );
+  assert.equal(
+    await at('weather-lightning', 'lightning', null, [-100, 10]),
+    false,
+  );
+  assert.equal(await at('weather-radar', 'radar', null, [50, 10]), false);
+  assert.equal(await at('weather-radar', 'radar', null, [50, -70]), true);
+  // An extent replaces the built-in gap.
+  const global = { extent: { west: -180, south: -52, east: 180, north: 52 } };
+  assert.equal(
+    await at('weather-lightning', 'lightning', global, [50, 10]),
+    false,
+  );
+  assert.equal(
+    await at('weather-lightning', 'lightning', global, [50, 60]),
+    true,
+  );
+  const europe = { extent: { west: -10, south: 35, east: 30, north: 70 } };
+  assert.equal(await at('weather-radar', 'radar', europe, [10, 50]), false);
+  assert.equal(await at('weather-radar', 'radar', europe, [-50, 50]), true);
+  assert.equal(await at('weather-radar', 'radar', europe, [10, 30]), true);
+  // West greater than east crosses the antimeridian.
+  const pacific = { extent: { west: 150, south: -30, east: -120, north: 60 } };
+  for (const [center, expected] of [
+    [[170, 0], false],
+    [[-150, 0], false],
+    [[0, 0], true],
+    [[-100, 0], true],
+    [[170, 70], true],
+  ])
+    assert.equal(
+      await at('weather-radar', 'radar', pacific, center),
+      expected,
+      `centre ${center}`,
+    );
+});
+
+test('switching to a product without display metadata restores its built-ins', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const h = await shownLayer('weather-satellite', {
+    ...base,
+    product: 'clouds-regional',
+    display: EXAMPLE,
+  });
+  h.manifests.clouds = { ...base, product: 'clouds' };
+  assert.equal(h.layer.getStats().source, 'Example network');
+  h.layer.setParams({ product: 'clouds' });
+  await flush();
+  assertBuiltIn(h.layer, 'clouds');
+  h.layer.setParams({ product: 'clouds-regional' });
+  await flush();
+  assert.equal(h.layer.getStats().source, 'Example network');
+  assert.equal(h.layer.getRowControls().summary.coverage, '52°S–52°N');
+  h.layer.destroy();
+});
+
+test('a refresh that drops display metadata restores the built-ins', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const h = await shownLayer('weather-lightning', {
+    ...base,
+    product: 'lightning',
+    display: EXAMPLE,
+  });
+  assert.equal(h.layer.getStats().source, 'Example network');
+  const plain = { ...base, product: 'lightning' };
+  h.manifests.lightning = plain;
+  await h.layer.update();
+  assertBuiltIn(h.layer, 'lightning');
+  assert.equal(h.snapshots.at(-1), plain, 'the renderer sees the refresh');
+  h.layer.destroy();
+});
+
+test('display validation bounds text, legend shape, colours and extents', () => {
+  const read = (display) => weatherDisplay({ display });
+  const scale = (legend) => read({ units: 'u', legend }).legend;
+  assert.deepEqual(read(undefined), {});
+  assert.deepEqual(read(['credit']), {});
+  assert.deepEqual(read({ coverage: '  Europe  ' }), { coverage: 'Europe' });
+  assert.deepEqual(read({ coverage: '   ' }), {});
+  assert.deepEqual(read({ credit: 'a b' }), {});
+  assert.deepEqual(read({ credit: 'x'.repeat(200) }).credit.length, 200);
+  assert.deepEqual(read({ credit: 'x'.repeat(201) }), {});
+  assert.deepEqual(read({ info: 'x'.repeat(601) }), {});
+  // Invisible and direction-changing characters are rejected in every field.
+  for (const code of [
+    0x00ad, 0x034f, 0x061c, 0x180e, 0x200b, 0x200d, 0x200e, 0x200f, 0x202a,
+    0x202d, 0x202e, 0x2060, 0x2066, 0x2069, 0xfe00, 0xfe0f, 0xfeff, 0xe0000,
+    0xe0001, 0xe0041, 0xe007f,
+  ]) {
+    const ch = String.fromCodePoint(code);
+    const value = `a${ch}b`;
+    for (const key of ['source', 'credit', 'units', 'coverage', 'info'])
+      assert.equal(
+        read({ [key]: value, legend: [{ label: 1, color: '#000000' }] })[key],
+        undefined,
+        `${key} with U+${ch.codePointAt(0).toString(16)}`,
+      );
+    assert.equal(
+      scale([
+        { label: '0', color: '#000000' },
+        { label: value, color: '#000000' },
+      ]),
+      undefined,
+    );
+  }
+  assert.equal(read({ coverage: 'a b · c–d' }).coverage, 'a b · c–d');
+  const stop = (label, color = '#000000') => ({ label, color });
+  assert.equal(scale([stop('1')]), undefined);
+  assert.equal(
+    scale(Array.from({ length: 17 }, (_, i) => stop(String(i)))),
+    undefined,
+  );
+  for (const bad of [
+    stop(Number.NaN),
+    stop(Infinity),
+    stop(0.1 + 0.2),
+    stop(1e21),
+    stop(1e-7),
+    stop(''),
+    stop('x'.repeat(17)),
+    stop('1', '#fff'),
+    stop('1', 'rgb(0,0,0)'),
+    stop('1', '#00000g'),
+    null,
+    '1',
+  ])
+    assert.equal(scale([stop('0'), bad]), undefined);
+  // A number label must read back exactly as the legend formats it.
+  for (const bad of [
+    '9999999999999999',
+    '9007199254740992',
+    '9007199254740992+',
+    '007',
+    '00.5',
+    9007199254740992,
+  ])
+    assert.equal(scale([stop('0'), stop(bad)]), undefined, String(bad));
+  assert.deepEqual(
+    scale([
+      stop('9007199254740991'),
+      stop(-900719925474099),
+      stop('-0.50'),
+      stop('1.25+'),
+      stop('123456.789012345'),
+    ]),
+    [
+      ['9007199254740991', '#000000'],
+      ['-900719925474099', '#000000'],
+      ['-0.50', '#000000'],
+      ['1.25+', '#000000'],
+      ['123456.789012345', '#000000'],
+    ],
+  );
+  for (const label of ['9007199254740991', '-0.50', '1.25+', '0.001'])
+    assert.equal(formatScaleLabel(label), label);
+  assert.equal(formatScaleLabel('9999999999999999'), '10000000000000000');
+  assert.deepEqual(scale([stop(0), stop(-2.5), stop('1', '#ABCDEF')]), [
+    ['0', '#000000'],
+    ['-2.5', '#000000'],
+    ['1', '#ABCDEF'],
+  ]);
+  // A legend needs its units and units need their legend.
+  assert.deepEqual(read({ units: 'u' }), {});
+  assert.deepEqual(read({ legend: [stop(0), stop(1)] }), {});
+  for (const bad of [
+    { west: -10, south: 0, east: 10 },
+    { west: -10, south: 0, east: 10, north: '5' },
+    { west: -181, south: 0, east: 10, north: 5 },
+    { west: -10, south: -91, east: 10, north: 5 },
+    { west: -10, south: 5, east: 10, north: 5 },
+    { west: -10, south: 6, east: 10, north: 5 },
+    { west: 10, south: 0, east: 10, north: 5 },
+    { west: 180, south: 0, east: -180, north: 5 },
+    { west: -180, south: 0, east: -180, north: 5 },
+  ])
+    assert.equal(read({ extent: bad }).extent, undefined, JSON.stringify(bad));
+  for (const good of [
+    { west: -180, south: -90, east: 180, north: 90 },
+    { west: 170, south: 0, east: -180, north: 5 },
+  ])
+    assert.deepEqual(read({ extent: good }).extent, good);
+  const wrap = read({ extent: { west: 110, south: -25, east: 0, north: 80 } });
+  assert.equal(insideExtent(wrap.extent, 150, 10), true);
+  assert.equal(insideExtent(wrap.extent, -100, 10), true);
+  assert.equal(insideExtent(wrap.extent, 50, 10), false);
+  assert.equal(insideExtent(wrap.extent, -100, 81), false);
+  assert.equal(
+    escapeCreditText(`<b>"A" & 'B'</b>`),
+    '&lt;b&gt;&quot;A&quot; &amp; &#39;B&#39;&lt;/b&gt;',
+  );
+});
+
+function mockCanvas() {
+  const canvas = { width: 0, height: 0 };
+  canvas.getContext = () => ({
+    setTransform() {},
+    drawImage() {},
+    getImageData: () => ({ data: new Uint8ClampedArray([194, 100, 0, 200]) }),
+    putImageData() {},
+  });
+  return canvas;
+}
+
+/** A globe viewer whose imagery collection records providers. */
+function globeViewer() {
+  const providers = [];
+  const layers = [];
+  const collection = {
+    addImageryProvider(provider) {
+      providers.push(provider);
+      const layer = { imageryProvider: provider, alpha: 1, show: true };
+      layers.push(layer);
+      return layer;
+    },
+    contains: (layer) => layers.includes(layer),
+    remove(layer) {
+      layers.splice(layers.indexOf(layer), 1);
+      return true;
+    },
+    get length() {
+      return layers.length;
+    },
+    get: (index) => layers[index],
+    indexOf: (layer) => layers.indexOf(layer),
+    lower() {},
+    raise() {},
+    raiseToTop() {},
+    isDestroyed: () => false,
+  };
+  const listeners = new Set();
+  const viewer = {
+    imageryLayers: collection,
+    camera: {
+      moveEnd: { addEventListener: () => () => {} },
+      flyTo() {},
+    },
+    scene: {
+      postRender: {
+        addEventListener(fn) {
+          listeners.add(fn);
+          return () => listeners.delete(fn);
+        },
+      },
+      primitives: createShellScene().primitives,
+      globe: { tilesLoaded: true },
+      requestRender() {},
+    },
+  };
+  class Provider {
+    constructor(options) {
+      this.options = options;
+      this.tilingScheme = new GeographicTilingScheme();
+      this.errorEvent = new Cesium.Event();
+    }
+    requestImage() {
+      return undefined;
+    }
+  }
+  const cesium = {
+    ...createShellCesium(),
+    UrlTemplateImageryProvider: Provider,
+    GeographicTilingScheme,
+    Event: Cesium.Event,
+    Credit: Cesium.Credit,
+    Rectangle: Cesium.Rectangle,
+  };
+  const options = {
+    cesium,
+    fetchImpl: async () => ({
+      ok: true,
+      headers: new Headers(),
+      arrayBuffer: async () => new ArrayBuffer(1),
+    }),
+    decodeImage: async () => ({ width: 2048, height: 1024, close() {} }),
+    createCanvas: mockCanvas,
+  };
+  const settle = async () => {
+    await flush();
+    for (let i = 0; i < 2; i++) for (const fn of [...listeners]) fn();
+    await flush();
+  };
+  return { viewer, providers, options, settle };
+}
+
+/** Show a frame of `manifest` and return the rendering and its globe. */
+async function shownFrame(manifest) {
+  const globe = globeViewer();
+  const rendering = createWeatherRendering({
+    viewer: globe.viewer,
+    ...globe.options,
+  });
+  const shown = rendering.setFrame(manifest, times[1]);
+  await globe.settle();
+  assert.equal(await shown, true);
+  return { ...globe, rendering };
+}
+
+const creditOf = (providers) => providers.at(-1).credit.html;
+
+test('the imagery credit uses the source credit as plain text, else the built-in one', async () => {
+  for (const product of ['radar', 'lightning', 'clouds-regional', 'clouds']) {
+    for (const display of [undefined, { credit: 42 }]) {
+      const h = await shownFrame({
+        ...base,
+        product,
+        ...(display ? { display } : {}),
+      });
+      assert.equal(creditOf(h.providers), BUILT_IN[product].credit, product);
+      h.rendering.clear();
+    }
+    const h = await shownFrame({
+      ...base,
+      product,
+      display: { credit: 'Example <network> & partners' },
+    });
+    assert.equal(
+      creditOf(h.providers),
+      'Example &lt;network&gt; &amp; partners',
+    );
+    h.rendering.clear();
+  }
+});
+
+test('a refreshed manifest updates the credit of the frame already shown', async () => {
+  for (const product of ['lightning', 'clouds']) {
+    const h = await shownFrame({
+      ...base,
+      product,
+      display: { credit: 'First credit' },
+    });
+    assert.equal(creditOf(h.providers), 'First credit');
+    const again = (display) =>
+      h.rendering.setFrame(
+        { ...base, product, ...(display ? { display } : {}) },
+        times[1],
+      );
+    assert.equal(await again({ credit: 'Second credit' }), true);
+    assert.equal(h.providers.length, 1, 'the frame is not restaged');
+    assert.equal(creditOf(h.providers), 'Second credit');
+    assert.equal(await again(), true);
+    assert.equal(creditOf(h.providers), BUILT_IN[product].credit);
+    h.rendering.updateSnapshot({
+      ...base,
+      product,
+      display: { credit: 'Third credit' },
+    });
+    assert.equal(creditOf(h.providers), 'Third credit');
+    // Another product's manifest leaves this frame alone.
+    h.rendering.updateSnapshot({
+      ...base,
+      product: 'radar',
+      display: { credit: 'Other' },
+    });
+    assert.equal(creditOf(h.providers), 'Third credit');
+    h.rendering.clear();
+  }
+});
+
+test('a refreshed manifest leaves the shown snapshot for a host switch to restage', async () => {
+  const globe = globeViewer();
+  let host = { collection: globe.viewer.imageryLayers, kind: 'globe' };
+  const staged = [];
+  const rendering = createWeatherRendering({
+    viewer: globe.viewer,
+    ...globe.options,
+    getHost: () => host,
+    createShell: ({ product }) => ({
+      product,
+      setAlpha() {},
+      setHidden() {},
+      rehome: () => false,
+      cancelPrefetch() {},
+      clear() {},
+      async setFrame(snapshot, time) {
+        staged.push([snapshot, time]);
+        return true;
+      },
+    }),
+  });
+  const first = {
+    ...base,
+    product: 'lightning',
+    display: { credit: 'First credit' },
+  };
+  const shown = rendering.setFrame(first, times[0]);
+  await globe.settle();
+  assert.equal(await shown, true);
+  const refreshed = {
+    ...first,
+    times: [times[1]],
+    bounds: { west: -10, south: 0, east: 10, north: 5 },
+    display: { credit: 'Second credit' },
+  };
+  rendering.updateSnapshot(refreshed);
+  assert.equal(creditOf(globe.providers), 'Second credit');
+  host = { collection: {}, kind: 'tileset' };
+  assert.equal(rendering.rehome(), true);
+  await flush();
+  assert.deepEqual(staged, [[first, times[0]]]);
+  host = { collection: globe.viewer.imageryLayers, kind: 'globe' };
+  assert.equal(rendering.rehome(), true);
+  await globe.settle();
+  assert.equal(globe.providers.length, 2);
+  const { west, south, east, north } = first.bounds;
+  assert.ok(
+    Cesium.Rectangle.equals(
+      globe.providers.at(-1).options.rectangle,
+      Cesium.Rectangle.fromDegrees(west, south, east, north),
+    ),
+    'the restaged frame keeps the bounds it was staged from',
+  );
+  assert.equal(creditOf(globe.providers), 'Second credit');
+  rendering.clear();
+});
+
+test('a layer refresh with the same latest frame updates the imagery credit', async (t) => {
+  t.mock.method(Date, 'now', () => Date.parse(times[1]));
+  const globe = globeViewer();
+  let manifest = {
+    ...base,
+    product: 'lightning',
+    display: { credit: 'First credit' },
+  };
+  const layer = createWeatherLayer({
+    id: 'weather-lightning',
+    feed: { getSnapshot: async () => manifest },
+    documentRef: quiet(),
+    eventTarget: quiet(),
+    matchMedia: () => quiet(),
+    createRendering: (args) =>
+      createWeatherRendering({ ...args, ...globe.options }),
+  });
+  layer.init(globe.viewer);
+  layer.enable();
+  const first = layer.update();
+  await globe.settle();
+  await first;
+  assert.equal(creditOf(globe.providers), 'First credit');
+  manifest = { ...manifest, display: { credit: 'Second credit' } };
+  await layer.update();
+  assert.equal(globe.providers.length, 1, 'the frame is not restaged');
+  assert.equal(creditOf(globe.providers), 'Second credit');
+  manifest = { ...base, product: 'lightning' };
+  await layer.update();
+  assert.equal(creditOf(globe.providers), BUILT_IN.lightning.credit);
+  layer.destroy();
+});
@@ -1,6 +1,7 @@
 import * as Cesium from 'cesium';
 import { createWeatherRendering } from './rendering.js';
 import { imageryHostStatus } from './imageryHost.js';
+import { weatherDisplay, insideExtent } from './display.js';
 import {
  RADAR_MAX_GAP_MS,
  REGIONAL_INFRARED_MAX_GAP_MS,
@@ -371,6 +372,8 @@ export function createWeatherLayer({
        }
        manifest = snapshot;
        error = null;
+        // The shown frame may stay; its credit follows the refreshed manifest.
+        rendering?.updateSnapshot?.(snapshot);
        if (clock) {
          await clock.refresh();
          if (
@@ -467,9 +470,11 @@ export function createWeatherLayer({
        manifest?.bounds &&
        runNavigation
      ) {
-        const b = lightning
-          ? { west: 110, south: -25, east: 0, north: 80 }
-          : manifest.bounds;
+        const b =
+          weatherDisplay(manifest).extent ??
+          (lightning
+            ? { west: 110, south: -25, east: 0, north: 80 }
+            : manifest.bounds);
        runNavigation(() =>
          viewer.camera.flyTo({
            destination: cesium.Rectangle.fromDegrees(
@@ -526,6 +531,8 @@ export function createWeatherLayer({
    getRowControls() {
      const shared = clock?.getState();
      const followLatest = isLatest();
+      // Source-described text is data: shown as is, never translated.
+      const display = weatherDisplay(manifest);
      const missing =
        noFrame &&
        shared?.mode === 'history' &&
@@ -592,7 +599,9 @@ export function createWeatherLayer({
          lon > b.east ||
          lat < b.south ||
          lat > b.north ||
-          (lightning && lon > 0 && lon < 110));
+          (display.extent
+            ? !insideExtent(display.extent, lon, lat)
+            : lightning && lon > 0 && lon < 110));
      let detail = time
        ? t('{state} · {time} · {lag}', {
            state: followLatest ? t('Observed') : t('History'),
@@ -606,7 +615,9 @@ export function createWeatherLayer({
      else if (relation === 'nearest')
        detail = t('{detail} · nearest', { detail });
      const infoHeading = radar
-        ? t('RADAR REFLECTIVITY · dBZ')
+        ? display.units !== undefined
+          ? t('RADAR · {units}', { units: display.units })
+          : t('RADAR REFLECTIVITY · dBZ')
        : lightning
          ? t('LIGHTNING DENSITY · 15 min accumulation')
          : product === 'clouds'
@@ -631,13 +642,24 @@ export function createWeatherLayer({
        : [t('Observation: unavailable'), loading ? t('loading') : '']
            .filter(Boolean)
            .join(' · ');
-      const infoCoverage = radar
-        ? t('Contiguous US · gaps ≠ no rain')
-        : lightning
-          ? `${t('Americas + Pacific · not individual strikes')}\n${t('Color: strikes/km²/min ×10³')}`
-          : product === 'clouds'
-            ? t('60°S–60°N · typically 2–3 h delayed')
-            : t('North America · infrared imagery');
+      const coverageLine =
+        display.coverage ??
+        (radar
+          ? t('Contiguous US · gaps ≠ no rain')
+          : lightning
+            ? t('Americas + Pacific · not individual strikes')
+            : product === 'clouds'
+              ? t('60°S–60°N · typically 2–3 h delayed')
+              : t('North America · infrared imagery'));
+      const infoCoverage = lightning
+        ? `${coverageLine}\n${
+            display.units === undefined
+              ? t('Color: strikes/km²/min ×10³')
+              : t('Color: {units}', { units: display.units })
+          }`
+        : coverageLine;
+      const stops =
+        display.legend ?? (radar ? STOPS : lightning ? LIGHTNING_STOPS : []);
      const infoMotion = motion?.matches
        ? clock
          ? t('Reduced motion · history playback unavailable')
@@ -651,13 +673,15 @@ export function createWeatherLayer({
            : lightning
              ? t('Lightning density · 15 min')
              : t('Satellite clouds'),
-          coverage: radar
-            ? 'CONUS'
-            : lightning
-              ? t('Americas + Pacific')
-              : product === 'clouds'
-                ? t('Global · 60°S–60°N')
-                : t('North America'),
+          coverage:
+            display.coverage ??
+            (radar
+              ? 'CONUS'
+              : lightning
+                ? t('Americas + Pacific')
+                : product === 'clouds'
+                  ? t('Global · 60°S–60°N')
+                  : t('North America')),
          shownTime: time,
          maxGapMinutes: maxGap() / 60_000,
          detail,
@@ -674,7 +698,11 @@ export function createWeatherLayer({
                  : outside
                    ? t('Map center outside coverage')
                    : null),
-          units: radar ? 'dBZ' : lightning ? t('strikes/km²/min ×10³') : '',
+          units:
+            display.units ??
+            (radar ? 'dBZ' : lightning ? t('strikes/km²/min ×10³') : ''),
+          // Source units are data: the panel shows them untranslated.
+          ...(display.units !== undefined ? { unitsVerbatim: true } : {}),
        },
        chips: [
          ...(satellite
@@ -723,43 +751,47 @@ export function createWeatherLayer({
          })),
          {
            id: 'coverage',
-            label: radar
-              ? t('View US radar')
-              : lightning
-                ? t('View Americas & Pacific')
-                : t('View coverage'),
+            label:
+              display.coverage !== undefined || display.extent !== undefined
+                ? t('View coverage')
+                : radar
+                  ? t('View US radar')
+                  : lightning
+                    ? t('View Americas & Pacific')
+                    : t('View coverage'),
            disabled: !manifest || !runNavigation,
            params: { focus: true },
          },
        ],
-        legend:
-          radar || lightning
-            ? (lightning ? LIGHTNING_STOPS : STOPS).map(([label, color]) => ({
-                label: String(label),
-                color,
-                blurb: lightning
-                  ? t('{value} strikes/km²/min ×10³ (15-minute density)', {
-                      value: formatScaleLabel(label),
-                    })
-                  : t('{value} dBZ radar reflectivity', {
-                      value: formatScaleLabel(label),
-                    }),
-              }))
-            : [],
+        legend: stops.map(([label, color]) => ({
+          label: String(label),
+          color,
+          blurb: display.legend
+            ? `${formatScaleLabel(label)} ${display.units}`
+            : lightning
+              ? t('{value} strikes/km²/min ×10³ (15-minute density)', {
+                  value: formatScaleLabel(label),
+                })
+              : t('{value} dBZ radar reflectivity', {
+                  value: formatScaleLabel(label),
+                }),
+        })),
        info: hostHidden
          ? shownHost
          : `${infoHeading}\n${infoTime}${missing ? `\n${missing}` : ''}${manifest?.stale ? `\n${t('STALE · cached source metadata')}` : ''}${shownProblem ? `\n${shownProblem}` : ''}\n${infoCoverage}${outside ? `\n${t('Map center is outside source coverage')}` : ''}${infoMotion ? `\n${infoMotion}` : ''}`,
-        infoTitle: lightning
-          ? t(
-              'NOAA/NWS 15-minute lightning density derived from Vaisala NLDN/GLD360. Coverage 110°E across the Pacific/Americas to 0°, 25°S–80°N. Not a live strike count, global coverage or a safety warning.',
-            )
-          : radar
+        infoTitle:
+          display.info ??
+          (lightning
            ? t(
-                'NOAA MRMS radar echoes indicate precipitation patterns, not rain rate, a storm warning or a future forecast. Native source approximately 1 km; display is limited to level 6. Frames use exact advertised observation times.',
+                'NOAA/NWS 15-minute lightning density derived from Vaisala NLDN/GLD360. Coverage 110°E across the Pacific/Americas to 0°, 25°S–80°N. Not a live strike count, global coverage or a safety warning.',
              )
-            : t(
-                'GOES-19/18 longwave infrared Band 14 regional; NESDIS global longwave mosaic. Clouds only dims everything but bright, cold cloud tops; a brightness filter, not a cloud mask. Coverage and freshness differ by region.',
-              ),
+            : radar
+              ? t(
+                  'NOAA MRMS radar echoes indicate precipitation patterns, not rain rate, a storm warning or a future forecast. Native source approximately 1 km; display is limited to level 6. Frames use exact advertised observation times.',
+                )
+              : t(
+                  'GOES-19/18 longwave infrared Band 14 regional; NESDIS global longwave mosaic. Clouds only dims everything but bright, cold cloud tops; a brightness filter, not a cloud mask. Coverage and freshness differ by region.',
+                )),
      };
      controls.summary.settings = [
        ...(satellite
@@ -805,6 +837,7 @@ export function createWeatherLayer({
      listener = typeof value === 'function' ? value : null;
    },
    getStats() {
+      const { source } = weatherDisplay(manifest);
      return {
        count: shownTime() ? 1 : 0,
        countLabel: isLatest() ? t('Observed') : t('History'),
@@ -812,7 +845,10 @@ export function createWeatherLayer({
        loading,
        error: error || rendering?.getDiagnostics().error || null,
        stale: Boolean(manifest?.stale || observationDelayed()),
-        source: 'NOAA nowCOAST',
+        ...(source === undefined
+          ? { source: 'NOAA nowCOAST' }
+          : // Source text is data: the panel shows it untranslated.
+            { source, sourceVerbatim: true }),
        observedAt: shownTime(),
      };
    },
@@ -3,6 +3,7 @@ import { orderWeatherImagery } from './imageryOrder.js';
 import { imageryHostStatus } from './imageryHost.js';
 import { createRasterTileProvider } from './rasterTiles.js';
 import { createWeatherShell } from './shellRendering.js';
+import { weatherDisplay, escapeCreditText } from './display.js';
 import { msg } from '../../i18n/index.js';
 import { readResponseBytesCapped } from '../../sources/httpBody.js';
 import {
@@ -116,6 +117,35 @@ function createGlobeRendering({
    return urls;
  }

+  function creditText(snapshot) {
+    const sourceCredit = weatherDisplay(snapshot).credit;
+    return sourceCredit !== undefined
+      ? escapeCreditText(sourceCredit)
+      : snapshot.product === 'lightning'
+        ? 'NOAA/NWS lightning density · derived from Vaisala NLDN/GLD360'
+        : snapshot.product === 'radar'
+          ? 'NOAA nowCOAST · NWS/OAR MRMS'
+          : 'NOAA nowCOAST · NESDIS GOES / global satellite partners';
+  }
+  function setCredit(frame, snapshot = frame.snapshot) {
+    const text = creditText(snapshot);
+    if (frame.credit?.html === text) return false;
+    frame.credit = new cesium.Credit(text, false);
+    return true;
+  }
+  /**
+   * Take the credit of a refreshed manifest of the same product. Each frame
+   * keeps the snapshot it was staged from, whose time and bounds still match.
+   */
+  function updateSnapshot(snapshot) {
+    let changed = false;
+    for (const frame of new Set([current, incoming, ...retiring])) {
+      if (!frame || frame.product !== snapshot.product) continue;
+      if (frame.credit && setCredit(frame, snapshot)) changed = true;
+    }
+    if (changed) viewer.scene.requestRender();
+  }
+
  function remove(frame) {
    if (!frame) return;
    frame.closed = true;
@@ -180,6 +210,7 @@ function createGlobeRendering({
  return {
    rehome,
    cancelPrefetch,
+    updateSnapshot,
    async prefetch(snapshot, time, { infrared = 'filtered' } = {}) {
      let job;
      try {
@@ -234,8 +265,10 @@ function createGlobeRendering({
        current.product === snapshot.product &&
        current.kind === kind &&
        current.infrared === infrared
-      )
+      ) {
+        updateSnapshot(snapshot);
        return true;
+      }
      lastError = null;
      const { west, south, east, north } = snapshot.bounds;
      const rectangle = cesium.Rectangle.fromDegrees(west, south, east, north);
@@ -342,14 +375,8 @@ function createGlobeRendering({
              }
            : undefined,
        );
-        const credit = new cesium.Credit(
-          snapshot.product === 'lightning'
-            ? 'NOAA/NWS lightning density · derived from Vaisala NLDN/GLD360'
-            : snapshot.product === 'radar'
-              ? 'NOAA nowCOAST · NWS/OAR MRMS'
-              : 'NOAA nowCOAST · NESDIS GOES / global satellite partners',
-          false,
-        );
+        setCredit(frame);
+        const credit = frame.credit;
        const provider = global
          ? createRasterTileProvider({
              cesium,
@@ -373,6 +400,13 @@ function createGlobeRendering({
              enablePickFeatures: false,
              credit,
            });
+        // Cesium reads a provider's credit every frame; a refreshed manifest
+        // can replace it without restaging the imagery.
+        Object.defineProperty(provider, 'credit', {
+          configurable: true,
+          enumerable: true,
+          get: () => frame.credit,
+        });
        const requestImage = provider.requestImage.bind(provider);
        provider.requestImage = (x, y, level, request) => {
          if (frame.closed) return undefined;
@@ -601,6 +635,8 @@ export function createWeatherRendering({
      if (restaging !== frame) return;
      restaging = null;
      if (!ok) onChange();
+      else if (frame.latest && target === globe)
+        globe.updateSnapshot(frame.latest);
    };
    target
      .setFrame(frame.snapshot, frame.time, { infrared: frame.infrared })
@@ -650,6 +686,13 @@ export function createWeatherRendering({
        shown = { snapshot, time, infrared: options.infrared ?? 'filtered' };
      return ok;
    },
+    // The shown frame keeps its staged snapshot for a restage on another
+    // host; only the refreshed credit is remembered and applied.
+    updateSnapshot(snapshot) {
+      if (shown?.snapshot.product === snapshot.product)
+        shown = { ...shown, latest: snapshot };
+      globe.updateSnapshot(snapshot);
+    },
    setHidden(value) {
      hidden = Boolean(value);
      if (hidden) restaging = null;
@@ -635,7 +635,11 @@ export class LayerPanel {
    const stats = layer.stats || {};
    const feedState = layerFeedState(stats);
    const stateLabel = t(FEED_STATE_LABEL_KEYS[feedState]);
-    const source = sourceLabel(stats.source || layer.source);
+    // A layer marks source text that is data rather than a catalog name.
+    const source =
+      stats.sourceVerbatim === true && stats.source
+        ? stats.source
+        : sourceLabel(stats.source || layer.source);
    const lifecycleState =
      layer.lifecycleState || (layer.enabled ? 'enabled' : 'disabled');
    if (lifecycleState === 'enabling' || lifecycleState === 'disabling') {
@@ -87,3 +87,21 @@ for (const locale of ['es', 'ru']) {
    }
  });
 }
+
+test('a source a layer marks as data is shown untranslated in the row', () => {
+  setLocale('ru');
+  try {
+    const row = (stats) =>
+      LayerPanel.prototype._buildMetaText({
+        id: 'weather-lightning',
+        enabled: true,
+        stats: { count: 1, lastUpdate: Date.now(), ...stats },
+      });
+    assert.match(row({ source: 'Local ADS-B' }), /Локальный ADS-B/);
+    const verbatim = row({ source: 'Local ADS-B', sourceVerbatim: true });
+    assert.match(verbatim, /Local ADS-B/);
+    assert.doesNotMatch(verbatim, /Локальный/);
+  } finally {
+    setLocale('en');
+  }
+});
@@ -16,9 +16,10 @@ const order = (parent, nodes) =>
      parent.insertBefore(node, parent.children[i] || null);
  });

-// "960 — 1050+ гПа": the unit stays with the last number.
-const scaleText = (low, high, units) => {
-  const unit = unitLabel(units);
+// "960 — 1050+ гПа": the unit stays with the last number. Units a source
+// supplied as data are shown as given.
+const scaleText = (low, high, units, verbatim) => {
+  const unit = verbatim ? units || '' : unitLabel(units);
  const range = `${formatScaleLabel(low)} — ${formatScaleLabel(high)}`;
  return unit ? `${range}\u00a0${unit}` : range;
 };
@@ -309,7 +310,12 @@ export function createRailCardBlocks({ container, cardId, onParams }) {
            block.scale,
            'textContent',
            visible
-              ? scaleText(legend.labels[0], legend.labels.at(-1), legend.units)
+              ? scaleText(
+                  legend.labels[0],
+                  legend.labels.at(-1),
+                  legend.units,
+                  legend.unitsVerbatim === true,
+                )
              : '',
          );
        } else if (props.type === 'actions') {
@@ -215,6 +215,7 @@ export function createWeatherPanel({
          colors: legend.map(({ color }) => color),
          labels: legend.map(({ label }) => label),
          units: categorical ? '' : summary.units,
+          ...(summary.unitsVerbatim === true ? { unitsVerbatim: true } : {}),
          zeroIndex: legend.findIndex(({ label }) => label === '0'),
        },
      };
@@ -752,3 +752,27 @@ test('air-quality readout renders its band legend, Canada coverage and worst-fir
  view.destroy();
  layer.destroy();
 });
+test('source-supplied legend units are shown as given; catalog units are translated', () => {
+  setLocale('ru');
+  try {
+    const f = fixture();
+    const view = createWeatherPanel(f);
+    const row = (summary) => ({
+      ...radar,
+      summary: { ...radar.summary, units: 'km/h', ...summary },
+      legend: [
+        { label: '1', color: '#000000' },
+        { label: '2', color: '#ffffff' },
+      ],
+    });
+    const scale = () =>
+      f.find((n) => n.className === 'rail-card-scale').textContent;
+    view.update([row()]);
+    assert.equal(scale(), '1 — 2 км/ч');
+    view.update([row({ unitsVerbatim: true })]);
+    assert.equal(scale(), '1 — 2 km/h');
+    view.destroy();
+  } finally {
+    setLocale('en');
+  }
+});