[feat](trx-frontend): improve AIS decode and decoder views

Improve the AIS decoder timing recovery, add AIS vessel linking and map trails, and make the AIS/APRS decoder panels behave like mode-bound views with full-height history panes.

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/decoders/trx-ais/src/lib.rs

@@ -50,10 +50,15 @@ struct RawFrame {
 #[derive(Debug, Clone)]
 pub struct AisDecoder {
     sample_rate: f32,
-    symbol_phase: f32,
+    samples_per_symbol: f32,
+    sample_clock: f32,
     dc_state: f32,
-    lp_state: f32,
+    lp_fast: f32,
+    lp_slow: f32,
     env_state: f32,
+    polarity: i8,
+    samples_since_transition: u32,
+    clock_locked: bool,
     prev_raw_bit: u8,
     ones: u32,
     in_frame: bool,
@@ -63,12 +68,18 @@ pub struct AisDecoder {
 
 impl AisDecoder {
     pub fn new(sample_rate: u32) -> Self {
+        let sample_rate = sample_rate.max(1) as f32;
         Self {
-            sample_rate: sample_rate.max(1) as f32,
+            sample_rate,
-            symbol_phase: 0.0,
+            samples_per_symbol: sample_rate / AIS_BAUD,
+            sample_clock: 0.0,
             dc_state: 0.0,
-            lp_state: 0.0,
+            lp_fast: 0.0,
+            lp_slow: 0.0,
             env_state: 1e-3,
+            polarity: 1,
+            samples_since_transition: 0,
+            clock_locked: false,
             prev_raw_bit: 0,
             ones: 0,
             in_frame: false,
@@ -78,10 +89,15 @@ impl AisDecoder {
     }
 
     pub fn reset(&mut self) {
-        self.symbol_phase = 0.0;
+        self.samples_per_symbol = self.sample_rate / AIS_BAUD;
+        self.sample_clock = 0.0;
         self.dc_state = 0.0;
-        self.lp_state = 0.0;
+        self.lp_fast = 0.0;
+        self.lp_slow = 0.0;
         self.env_state = 1e-3;
+        self.polarity = 1;
+        self.samples_since_transition = 0;
+        self.clock_locked = false;
         self.prev_raw_bit = 0;
         self.ones = 0;
         self.in_frame = false;
@@ -109,25 +125,59 @@ impl AisDecoder {
         self.dc_state += 0.0025 * (sample - self.dc_state);
         let dc_free = sample - self.dc_state;
 
-        // Gentle low-pass smoothing to suppress narrow impulsive noise.
+        // A simple band-pass-ish response makes GMSK symbol transitions stand out
-        self.lp_state += 0.28 * (dc_free - self.lp_state);
+        // without needing a full matched filter.
+        self.lp_fast += 0.32 * (dc_free - self.lp_fast);
+        self.lp_slow += 0.045 * (dc_free - self.lp_slow);
+        let shaped = self.lp_fast - self.lp_slow;
 
         // Track envelope to keep the slicer stable on weak signals.
-        self.env_state += 0.02 * (self.lp_state.abs() - self.env_state);
+        self.env_state += 0.015 * (shaped.abs() - self.env_state);
         let normalized = if self.env_state > 1e-4 {
-            self.lp_state / self.env_state
+            shaped / self.env_state
         } else {
-            self.lp_state
+            shaped
         };
 
-        self.symbol_phase += AIS_BAUD;
+        let threshold = 0.12;
-        while self.symbol_phase >= self.sample_rate {
+        let next_polarity = if normalized > threshold {
-            self.symbol_phase -= self.sample_rate;
+            1
-            let raw_bit = if normalized >= 0.0 { 1 } else { 0 };
+        } else if normalized < -threshold {
+            -1
+        } else {
+            self.polarity
+        };
+
+        self.samples_since_transition = self.samples_since_transition.saturating_add(1);
+        if next_polarity != self.polarity {
+            self.observe_transition();
+            self.polarity = next_polarity;
+        }
+
+        if !self.clock_locked {
+            return;
+        }
+
+        self.sample_clock += 1.0;
+        while self.sample_clock >= self.samples_per_symbol {
+            self.sample_clock -= self.samples_per_symbol;
+            let raw_bit = if self.polarity >= 0 { 1 } else { 0 };
             self.process_symbol(raw_bit);
         }
     }
 
+    fn observe_transition(&mut self) {
+        let interval = self.samples_since_transition.max(1) as f32;
+        self.samples_since_transition = 0;
+
+        let nominal = (self.sample_rate / AIS_BAUD).max(1.0);
+        let symbols = (interval / nominal).round().clamp(1.0, 8.0);
+        let estimate = (interval / symbols).clamp(nominal * 0.75, nominal * 1.25);
+        self.samples_per_symbol += 0.18 * (estimate - self.samples_per_symbol);
+        self.sample_clock = self.samples_per_symbol * 0.5;
+        self.clock_locked = true;
+    }
+
     fn process_symbol(&mut self, raw_bit: u8) {
         let decoded_bit = if raw_bit == self.prev_raw_bit { 1 } else { 0 };
         self.prev_raw_bit = raw_bit;
@@ -146,7 +196,7 @@ impl AisDecoder {
         }
 
         if self.ones == 6 {
-            if self.in_frame && self.frame_bits.len() >= 256 {
+            if self.in_frame {
                 if let Some(frame) = self.bits_to_frame() {
                     self.frames.push(frame);
                 }
@@ -373,6 +423,52 @@ fn decode_sixbit_text(bits: &[u8], start: usize, len: usize) -> Option<String> {
 mod tests {
     use super::*;
 
+    fn payload_with_crc(payload: &[u8]) -> Vec<u8> {
+        let mut out = payload.to_vec();
+        out.extend_from_slice(&crc16ccitt(payload).to_le_bytes());
+        out
+    }
+
+    fn bytes_to_lsb_bits(bytes: &[u8]) -> Vec<u8> {
+        let mut bits = Vec::with_capacity(bytes.len() * 8);
+        for &byte in bytes {
+            for shift in 0..8 {
+                bits.push((byte >> shift) & 1);
+            }
+        }
+        bits
+    }
+
+    fn bitstuff(bits: &[u8]) -> Vec<u8> {
+        let mut out = Vec::with_capacity(bits.len() + bits.len() / 5);
+        let mut ones = 0u32;
+        for &bit in bits {
+            out.push(bit);
+            if bit == 1 {
+                ones += 1;
+                if ones == 5 {
+                    out.push(0);
+                    ones = 0;
+                }
+            } else {
+                ones = 0;
+            }
+        }
+        out
+    }
+
+    fn nrzi_encode(bits: &[u8]) -> Vec<u8> {
+        let mut state = 0u8;
+        let mut out = Vec::with_capacity(bits.len());
+        for &bit in bits {
+            if bit == 0 {
+                state ^= 1;
+            }
+            out.push(state);
+        }
+        out
+    }
+
     #[test]
     fn decodes_signed_coordinates() {
         assert_eq!(decode_coord(60_000, 181.0), Some(0.1));
@@ -386,4 +482,24 @@ mod tests {
         let text = decode_sixbit_text(&bits, 0, 36);
         assert!(text.is_some());
     }
+
+    #[test]
+    fn recovers_hdlc_frame_from_raw_nrzi_bits() {
+        let payload = [0x11_u8, 0x22_u8, 0x7E_u8, 0x00_u8, 0xF0_u8];
+        let frame_bytes = payload_with_crc(&payload);
+        let mut hdlc_bits = bytes_to_lsb_bits(&[0x7E]);
+        hdlc_bits.extend(bitstuff(&bytes_to_lsb_bits(&frame_bytes)));
+        hdlc_bits.extend(bytes_to_lsb_bits(&[0x7E]));
+        let raw_bits = nrzi_encode(&hdlc_bits);
+
+        let mut decoder = AisDecoder::new(48_000);
+        for raw_bit in raw_bits {
+            decoder.process_symbol(raw_bit);
+        }
+
+        assert_eq!(decoder.frames.len(), 1);
+        let frame = &decoder.frames[0];
+        assert!(frame.crc_ok);
+        assert_eq!(frame.payload, payload);
+    }
 }

src/trx-client/src/config.rs

@@ -41,6 +41,8 @@ pub struct GeneralConfig {
     pub website_url: Option<String>,
     /// Optional website name to use as the web UI header title label.
     pub website_name: Option<String>,
+    /// Optional base URL used to link AIS vessel names as `<base><mmsi>`.
+    pub ais_vessel_url_base: Option<String>,
     /// Log level (trace, debug, info, warn, error)
     pub log_level: Option<String>,
 }
@@ -51,6 +53,7 @@ impl Default for GeneralConfig {
             callsign: Some("N0CALL".to_string()),
             website_url: None,
             website_name: None,
+            ais_vessel_url_base: Some("https://www.vesselfinder.com/?mmsi=".to_string()),
             log_level: None,
         }
     }
@@ -356,6 +359,11 @@ impl ClientConfig {
                 return Err("[general].website_name must not be empty when set".to_string());
             }
         }
+        if let Some(url) = &self.general.ais_vessel_url_base {
+            if url.trim().is_empty() {
+                return Err("[general].ais_vessel_url_base must not be empty when set".to_string());
+            }
+        }
 
         if self.frontends.http.enabled && self.frontends.http.port == 0 {
             return Err("[frontends.http].port must be > 0 when enabled".to_string());
@@ -459,6 +467,7 @@ impl ClientConfig {
                 callsign: Some("N0CALL".to_string()),
                 website_url: Some("https://haxx.space".to_string()),
                 website_name: Some("haxx.space".to_string()),
+                ais_vessel_url_base: Some("https://www.vesselfinder.com/?mmsi=".to_string()),
                 log_level: Some("info".to_string()),
             },
             remote: RemoteConfig {
@@ -586,6 +595,7 @@ mod tests {
         assert!(config.remote.url.is_none());
         assert!(config.general.website_url.is_none());
         assert!(config.general.website_name.is_none());
+        assert!(config.general.ais_vessel_url_base.is_none());
         assert_eq!(config.remote.poll_interval_ms, 750);
         assert!(config.frontends.audio.enabled);
         assert_eq!(config.frontends.audio.server_port, 4531);
@@ -602,6 +612,7 @@ mod tests {
 callsign = "W1AW"
 website_url = "https://example.com"
 website_name = "Example"
+ais_vessel_url_base = "https://example.com/vessel/"
 
 [remote]
 url = "192.168.1.100:9000"
@@ -623,6 +634,10 @@ spectrum_usable_span_ratio = 0.9
         assert_eq!(config.general.callsign, Some("W1AW".to_string()));
         assert_eq!(config.general.website_url, Some("https://example.com".to_string()));
         assert_eq!(config.general.website_name, Some("Example".to_string()));
+        assert_eq!(
+            config.general.ais_vessel_url_base,
+            Some("https://example.com/vessel/".to_string())
+        );
         assert_eq!(config.remote.url, Some("192.168.1.100:9000".to_string()));
         assert_eq!(config.remote.rig_id, Some("hf".to_string()));
         assert_eq!(config.remote.auth.token, Some("my-token".to_string()));

src/trx-client/src/main.rs

@@ -250,6 +250,7 @@ async fn async_init() -> DynResult<AppState> {
     frontend_runtime.owner_callsign = callsign.clone();
     frontend_runtime.owner_website_url = cfg.general.website_url.clone();
     frontend_runtime.owner_website_name = cfg.general.website_name.clone();
+    frontend_runtime.ais_vessel_url_base = cfg.general.ais_vessel_url_base.clone();
 
     info!(
         "Starting trx-client (remote: {}, frontends: {})",

src/trx-client/trx-frontend/src/lib.rs

@@ -186,6 +186,8 @@ pub struct FrontendRuntimeContext {
     pub owner_website_url: Option<String>,
     /// Optional website name for the web UI header title label.
     pub owner_website_name: Option<String>,
+    /// Optional base URL used to link AIS vessel names as `<base><mmsi>`.
+    pub ais_vessel_url_base: Option<String>,
     /// Latest spectrum frame from the active SDR rig; None for non-SDR backends.
     pub spectrum: Arc<Mutex<SharedSpectrum>>,
 }
@@ -223,6 +225,7 @@ impl FrontendRuntimeContext {
             owner_callsign: None,
             owner_website_url: None,
             owner_website_name: None,
+            ais_vessel_url_base: None,
             spectrum: Arc::new(Mutex::new(SharedSpectrum::default())),
         }
     }

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -1723,6 +1723,7 @@ let serverCallsign = null;
 let ownerCallsign = null;
 let ownerWebsiteUrl = null;
 let ownerWebsiteName = null;
+let aisVesselUrlBase = null;
 let serverRigs = [];
 let serverActiveRigId = null;
 let serverLat = null;
@@ -1814,6 +1815,11 @@ function displayLabelFromUrl(url) {
   }
 }
 
+window.buildAisVesselUrl = function(mmsi) {
+  if (!aisVesselUrlBase || !Number.isFinite(Number(mmsi))) return null;
+  return `${aisVesselUrlBase}${String(mmsi)}`;
+};
+
 function render(update) {
   if (!update) return;
   if (update.server_version) serverVersion = update.server_version;
@@ -1828,6 +1834,9 @@ function render(update) {
   if (typeof update.owner_website_name === "string" && update.owner_website_name.length > 0) {
     ownerWebsiteName = update.owner_website_name;
   }
+  if (typeof update.ais_vessel_url_base === "string" && update.ais_vessel_url_base.length > 0) {
+    aisVesselUrlBase = update.ais_vessel_url_base;
+  }
   if (update.server_latitude != null) serverLat = update.server_latitude;
   if (update.server_longitude != null) serverLon = update.server_longitude;
   if (typeof update.initial_map_zoom === "number" && Number.isFinite(update.initial_map_zoom)) {
@@ -1994,13 +2003,19 @@ function render(update) {
   const cwStatus = document.getElementById("cw-status");
   const ft8Status = document.getElementById("ft8-status");
   const wsprStatus = document.getElementById("wspr-status");
-  if (aisStatus && modeUpper !== "AIS" && aisStatus.textContent === "Receiving") {
+  setModeBoundDecodeStatus(
-    aisStatus.textContent = "Connected, listening for packets";
+    aisStatus,
-  }
+    ["AIS"],
+    "Select AIS mode to decode",
+    "Connected, listening for packets",
+  );
   if (window.updateAisBar) window.updateAisBar();
-  if (aprsStatus && modeUpper !== "PKT" && aprsStatus.textContent === "Receiving") {
+  setModeBoundDecodeStatus(
-    aprsStatus.textContent = "Connected, listening for packets";
+    aprsStatus,
-  }
+    ["PKT"],
+    "Select PKT mode to decode",
+    "Connected, listening for packets",
+  );
   if (window.updateAprsBar) window.updateAprsBar();
   if (cwStatus && modeUpper !== "CW" && modeUpper !== "CWR" && cwStatus.textContent === "Receiving") {
     cwStatus.textContent = "Connected, listening for packets";
@@ -2969,6 +2984,7 @@ const locatorMarkers = new Map();
 const mapMarkers = new Set();
 const mapFilter = { ais: true, aprs: true, ft8: true, wspr: true };
 const APRS_TRACK_MAX_POINTS = 64;
+const AIS_TRACK_MAX_POINTS = 64;
 const aisMarkers = new Map();
 
 window.clearMapMarkersByType = function(type) {
@@ -2993,6 +3009,10 @@ window.clearMapMarkersByType = function(type) {
         if (aprsMap && aprsMap.hasLayer(entry.marker)) entry.marker.removeFrom(aprsMap);
         mapMarkers.delete(entry.marker);
       }
+      if (entry && entry.track) {
+        if (aprsMap && aprsMap.hasLayer(entry.track)) entry.track.removeFrom(aprsMap);
+        mapMarkers.delete(entry.track);
+      }
     });
     aisMarkers.clear();
     return;
@@ -3261,12 +3281,20 @@ function buildAisPopupHtml(msg) {
   let rows = "";
   rows += `<tr><td class="aprs-popup-label">MMSI</td><td>${escapeMapHtml(String(msg.mmsi || "--"))}</td></tr>`;
   rows += `<tr><td class="aprs-popup-label">Type</td><td>${escapeMapHtml(String(msg.message_type || "--"))}</td></tr>`;
+  if (distStr) rows += `<tr><td class="aprs-popup-label">Range</td><td>${distStr} from TRX</td></tr>`;
   if (msg?.sog_knots != null) rows += `<tr><td class="aprs-popup-label">SOG</td><td>${Number(msg.sog_knots).toFixed(1)} kn</td></tr>`;
   if (msg?.cog_deg != null) rows += `<tr><td class="aprs-popup-label">COG</td><td>${Number(msg.cog_deg).toFixed(1)}&deg;</td></tr>`;
+  if (msg?.heading_deg != null) rows += `<tr><td class="aprs-popup-label">HDG</td><td>${Number(msg.heading_deg).toFixed(0)}&deg;</td></tr>`;
+  if (msg?.nav_status != null) rows += `<tr><td class="aprs-popup-label">Nav</td><td>${escapeMapHtml(String(msg.nav_status))}</td></tr>`;
   if (msg?.lat != null && msg?.lon != null) rows += `<tr><td class="aprs-popup-label">Pos</td><td>${msg.lat.toFixed(5)}, ${msg.lon.toFixed(5)}</td></tr>`;
   const info = [msg?.vessel_name, msg?.callsign, msg?.destination].filter(Boolean).map(escapeMapHtml).join(" · ");
+  const vesselLabel = escapeMapHtml(msg?.vessel_name || `MMSI ${msg?.mmsi || "--"}`);
+  const vesselUrl = window.buildAisVesselUrl ? window.buildAisVesselUrl(msg?.mmsi) : null;
+  const vesselTitle = vesselUrl
+    ? `<a class="title-link" href="${escapeMapHtml(vesselUrl)}" target="_blank" rel="noopener">${vesselLabel}</a>`
+    : vesselLabel;
   return `<div class="aprs-popup">` +
-    `<div class="aprs-popup-call">${escapeMapHtml(msg?.vessel_name || `MMSI ${msg?.mmsi || "--"}`)}</div>` +
+    `<div class="aprs-popup-call">${vesselTitle}</div>` +
     (meta ? `<div class="aprs-popup-meta">${meta}</div>` : "") +
     (rows ? `<table class="aprs-popup-table">${rows}</table>` : "") +
     (info ? `<div class="aprs-popup-info">${info}</div>` : "") +
@@ -3278,6 +3306,11 @@ function aprsPositionsEqual(a, b) {
   return Math.abs(a[0] - b[0]) < 0.000001 && Math.abs(a[1] - b[1]) < 0.000001;
 }
 
+function aisPositionsEqual(a, b) {
+  if (!a || !b) return false;
+  return Math.abs(a[0] - b[0]) < 0.000001 && Math.abs(a[1] - b[1]) < 0.000001;
+}
+
 function ensureAprsTrack(call, entry) {
   if (!aprsMap || !entry || !Array.isArray(entry.trackPoints) || entry.trackPoints.length < 2) return;
   if (entry.track) {
@@ -3361,16 +3394,52 @@ window.aprsMapAddStation = function(call, lat, lon, info, symbolTable, symbolCod
   }
 };
 
+function ensureAisTrack(mmsi, entry) {
+  if (!aprsMap || !entry || !Array.isArray(entry.trackPoints) || entry.trackPoints.length < 2) return;
+  if (entry.track) {
+    entry.track.setLatLngs(entry.trackPoints);
+    return;
+  }
+  const track = L.polyline(entry.trackPoints, {
+    color: "#ff7559",
+    weight: 2,
+    opacity: 0.68,
+    lineCap: "round",
+    lineJoin: "round",
+    interactive: false,
+    dashArray: "5 4",
+  });
+  track.__trxType = "ais";
+  track._aisMmsi = mmsi;
+  entry.track = track;
+  mapMarkers.add(track);
+  if (mapFilter.ais) {
+    track.addTo(aprsMap);
+  }
+}
+
 window.aisMapAddVessel = function(msg) {
   if (msg == null || msg.lat == null || msg.lon == null || !Number.isFinite(msg.mmsi)) return;
   if (!aprsMap) initAprsMap();
   const key = String(msg.mmsi);
   const popupHtml = buildAisPopupHtml(msg);
+  const nextPoint = [msg.lat, msg.lon];
   const existing = aisMarkers.get(key);
-  if (existing && existing.marker) {
+  if (existing) {
     existing.msg = msg;
-    existing.marker.setLatLng([msg.lat, msg.lon]);
+    if (!Array.isArray(existing.trackPoints)) existing.trackPoints = [];
-    existing.marker.setPopupContent(popupHtml);
+    const prevPoint = existing.trackPoints[existing.trackPoints.length - 1];
+    if (!aisPositionsEqual(prevPoint, nextPoint)) {
+      existing.trackPoints.push(nextPoint);
+      if (existing.trackPoints.length > AIS_TRACK_MAX_POINTS) {
+        existing.trackPoints.splice(0, existing.trackPoints.length - AIS_TRACK_MAX_POINTS);
+      }
+      ensureAisTrack(key, existing);
+    }
+    if (existing.marker) {
+      existing.marker.setLatLng([msg.lat, msg.lon]);
+      existing.marker.setPopupContent(popupHtml);
+    }
     return;
   }
   if (!aprsMap) return;
@@ -3381,8 +3450,14 @@ window.aisMapAddVessel = function(msg) {
     fillOpacity: 0.82,
   }).addTo(aprsMap).bindPopup(popupHtml);
   marker.__trxType = "ais";
+  marker._aisMmsi = key;
   mapMarkers.add(marker);
-  aisMarkers.set(key, { marker, msg });
+  aisMarkers.set(key, {
+    marker,
+    track: null,
+    trackPoints: [nextPoint],
+    msg,
+  });
   applyMapFilter();
 };
 
@@ -4109,13 +4184,20 @@ document.getElementById("copyright-year").textContent = new Date().getFullYear()
 // --- Server-side decode SSE ---
 let decodeSource = null;
 let decodeConnected = false;
+function setModeBoundDecodeStatus(el, activeModes, inactiveText, connectedText) {
+  if (!el) return;
+  const modeUpper = (document.getElementById("mode")?.value || "").toUpperCase();
+  const isActiveMode = activeModes.includes(modeUpper);
+  if (el.textContent === "Receiving" && isActiveMode) return;
+  el.textContent = isActiveMode ? connectedText : inactiveText;
+}
 function updateDecodeStatus(text) {
   const ais = document.getElementById("ais-status");
   const aprs = document.getElementById("aprs-status");
   const cw = document.getElementById("cw-status");
   const ft8 = document.getElementById("ft8-status");
-  if (ais && ais.textContent !== "Receiving") ais.textContent = text;
+  setModeBoundDecodeStatus(ais, ["AIS"], "Select AIS mode to decode", text);
-  if (aprs && aprs.textContent !== "Receiving") aprs.textContent = text;
+  setModeBoundDecodeStatus(aprs, ["PKT"], "Select PKT mode to decode", text);
   if (cw && cw.textContent !== "Receiving") cw.textContent = text;
   if (ft8 && ft8.textContent !== "Receiving") ft8.textContent = text;
 }

src/trx-client/trx-frontend/trx-frontend-http/assets/web/plugins/ais.js

@@ -49,6 +49,13 @@ function aisDisplayName(msg) {
   return msg.vessel_name || msg.callsign || `MMSI ${msg.mmsi}`;
 }
 
+function aisDisplayNameHtml(msg) {
+  const label = escapeMapHtml(aisDisplayName(msg));
+  const url = window.buildAisVesselUrl ? window.buildAisVesselUrl(msg?.mmsi) : null;
+  if (!url) return label;
+  return `<a class="title-link" href="${escapeMapHtml(url)}" target="_blank" rel="noopener">${label}</a>`;
+}
+
 function aisTypeLabel(type) {
   switch (Number(type)) {
     case 1:
@@ -97,6 +104,16 @@ function aisRouteText(msg) {
   return [msg.callsign, msg.destination].filter(Boolean).join(" -> ");
 }
 
+function aisDistanceText(msg) {
+  if (serverLat == null || serverLon == null || msg?.lat == null || msg?.lon == null) {
+    return "";
+  }
+  const distKm = haversineKm(serverLat, serverLon, msg.lat, msg.lon);
+  if (!Number.isFinite(distKm)) return "";
+  if (distKm < 1) return `${Math.round(distKm * 1000)} m from TRX`;
+  return `${distKm.toFixed(1)} km from TRX`;
+}
+
 function aisLatestByVessel(messages) {
   const byMmsi = new Map();
   for (const msg of messages) {
@@ -138,9 +155,11 @@ function renderAisRow(msg) {
     second: "2-digit",
   });
   const name = aisDisplayName(msg);
+  const nameHtml = aisDisplayNameHtml(msg);
   const channel = aisChannelInfo(msg.channel);
   const motion = aisMotionText(msg);
   const route = aisRouteText(msg);
+  const distance = aisDistanceText(msg);
   const pos = msg.lat != null && msg.lon != null
     ? `<a class="ais-pos-link" href="javascript:void(0)" onclick="window.navigateToAprsMap(${msg.lat},${msg.lon})">${msg.lat.toFixed(4)}, ${msg.lon.toFixed(4)}</a>`
     : "";
@@ -160,7 +179,7 @@ function renderAisRow(msg) {
   row.innerHTML =
     `<div class="ais-row-head">` +
       `<span class="ais-time">${ts}</span>` +
-      `<span class="ais-call">${escapeMapHtml(name)}</span>` +
+      `<span class="ais-call">${nameHtml}</span>` +
       `<span class="${channel.badgeClass}">${escapeMapHtml(channel.label)}</span>` +
       `<span class="ais-badge ais-badge-type">${escapeMapHtml(aisTypeLabel(msg.message_type))}</span>` +
     `</div>` +
@@ -171,6 +190,7 @@ function renderAisRow(msg) {
     `</div>` +
     `<div class="ais-row-detail">` +
       (motion ? `<span>${escapeMapHtml(motion)}</span>` : `<span>No motion data</span>`) +
+      (distance ? `<span>${escapeMapHtml(distance)}</span>` : "") +
       (pos ? `<span>${pos}</span>` : "") +
       `<span>${escapeMapHtml(aisAgeText(msg._tsMs))}</span>` +
     `</div>`;
@@ -213,13 +233,15 @@ function updateAisBar() {
     const pin = msg.lat != null && msg.lon != null
       ? `<button class="aprs-bar-pin" title="${msg.lat.toFixed(4)}, ${msg.lon.toFixed(4)}" onclick="window.navigateToAprsMap(${msg.lat},${msg.lon})">📍</button>`
       : "";
-    const name = `<span class="ais-call">${escapeMapHtml(aisDisplayName(msg))}</span>`;
+    const name = `<span class="ais-call">${aisDisplayNameHtml(msg)}</span>`;
     const channel = aisChannelInfo(msg.channel);
+    const distance = aisDistanceText(msg);
     const details = [
       `MMSI ${escapeMapHtml(String(msg.mmsi))}`,
       escapeMapHtml(channel.label),
       msg.sog_knots != null ? `${Number(msg.sog_knots).toFixed(1)} kn` : null,
       msg.cog_deg != null ? `${Number(msg.cog_deg).toFixed(1)}°` : null,
+      distance ? escapeMapHtml(distance) : null,
       escapeMapHtml(aisAgeText(msg._tsMs)),
     ]
       .filter(Boolean)

src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css

@@ -1116,8 +1116,28 @@ small { color: var(--text-muted); }
   font-size: 0.8rem;
   line-height: 1.3;
 }
+#subtab-ais {
+  display: flex;
+  flex-direction: column;
+  min-height: calc(100vh - 18rem);
+}
+#subtab-aprs {
+  display: flex;
+  flex-direction: column;
+  min-height: calc(100vh - 18rem);
+}
 #aprs-packets,
 #ais-messages { max-height: 360px; overflow-y: auto; border: 1px solid var(--border-light); border-radius: 6px; background: var(--input-bg); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; }
+#aprs-packets {
+  flex: 1 1 auto;
+  min-height: calc(100vh - 21rem);
+  max-height: none;
+}
+#ais-messages {
+  flex: 1 1 auto;
+  min-height: calc(100vh - 24rem);
+  max-height: none;
+}
 .aprs-packet { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.82rem; padding: 0.35rem 0.5rem; border-bottom: 1px solid var(--border); line-height: 1.4; }
 .aprs-packet:last-child { border-bottom: none; }
 .ais-message { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.82rem; padding: 0.45rem 0.55rem; border-bottom: 1px solid var(--border); line-height: 1.35; }
@@ -1534,6 +1554,18 @@ button:focus-visible, input:focus-visible, select:focus-visible {
   .ais-summary {
     grid-template-columns: minmax(0, 1fr);
   }
+  #subtab-ais {
+    min-height: calc(100vh - 14rem);
+  }
+  #subtab-aprs {
+    min-height: calc(100vh - 14rem);
+  }
+  #aprs-packets {
+    min-height: calc(100vh - 19rem);
+  }
+  #ais-messages {
+    min-height: calc(100vh - 22rem);
+  }
   .aprs-controls > button,
   .ft8-controls > button,
   .cw-controls > button {

src/trx-client/trx-frontend/trx-frontend-http/src/api.rs

@@ -39,6 +39,7 @@ struct FrontendMeta {
     owner_callsign: Option<String>,
     owner_website_url: Option<String>,
     owner_website_name: Option<String>,
+    ais_vessel_url_base: Option<String>,
     show_sdr_gain_control: bool,
     initial_map_zoom: u8,
     spectrum_coverage_margin_hz: u32,
@@ -93,6 +94,9 @@ fn inject_frontend_meta(json: &str, meta: FrontendMeta) -> String {
     if let Some(name) = meta.owner_website_name {
         map.insert("owner_website_name".to_string(), serde_json::json!(name));
     }
+    if let Some(url) = meta.ais_vessel_url_base {
+        map.insert("ais_vessel_url_base".to_string(), serde_json::json!(url));
+    }
     map.insert(
         "show_sdr_gain_control".to_string(),
         serde_json::json!(meta.show_sdr_gain_control),
@@ -126,6 +130,7 @@ fn frontend_meta_from_context(
         owner_callsign: owner_callsign_from_context(context),
         owner_website_url: owner_website_url_from_context(context),
         owner_website_name: owner_website_name_from_context(context),
+        ais_vessel_url_base: ais_vessel_url_base_from_context(context),
         show_sdr_gain_control: show_sdr_gain_control_from_context(context),
         initial_map_zoom: initial_map_zoom_from_context(context),
         spectrum_coverage_margin_hz: spectrum_coverage_margin_hz_from_context(context),
@@ -171,6 +176,10 @@ fn owner_website_name_from_context(context: &FrontendRuntimeContext) -> Option<S
     context.owner_website_name.clone()
 }
 
+fn ais_vessel_url_base_from_context(context: &FrontendRuntimeContext) -> Option<String> {
+    context.ais_vessel_url_base.clone()
+}
+
 fn show_sdr_gain_control_from_context(context: &FrontendRuntimeContext) -> bool {
     context.http_show_sdr_gain_control
 }