From 6fd5098b89b6f8e102600bd9290d4fb5ba68a9b6 Mon Sep 17 00:00:00 2001
From: James Smith <jsmith@Jamess-MacBook-Pro.local>
Date: Wed, 18 Mar 2026 22:43:40 +0000
Subject: [PATCH] Clear stale telemetry and add transmitter fallbacks

---
 templates/satellite_dashboard.html | 21 ++++++++-
 utils/satnogs.py                   | 71 +++++++++++++++++++++++++++---
 2 files changed, 86 insertions(+), 6 deletions(-)

diff --git a/templates/satellite_dashboard.html b/templates/satellite_dashboard.html
index eacf4dd..87d4b1f 100644
--- a/templates/satellite_dashboard.html
+++ b/templates/satellite_dashboard.html
@@ -666,6 +666,7 @@
                 if (orbitTrack) { groundMap.removeLayer(orbitTrack); orbitTrack = null; }
             }
 
+            clearTelemetry();
             loadTransmitters(selectedSatellite);
             calculatePasses();
             fetchCurrentTelemetry();
@@ -744,7 +745,10 @@
             const visEl = document.getElementById('statVisible');
             if (visEl) visEl.textContent = visibleCount;
 
-            if (!pos) return;
+            if (!pos) {
+                clearTelemetry();
+                return;
+            }
 
             // Update telemetry panel
             const telLat = document.getElementById('telLat');
@@ -788,6 +792,21 @@
             }
         }
 
+        function clearTelemetry() {
+            const telLat = document.getElementById('telLat');
+            const telLon = document.getElementById('telLon');
+            const telAlt = document.getElementById('telAlt');
+            const telEl = document.getElementById('telEl');
+            const telAz = document.getElementById('telAz');
+            const telDist = document.getElementById('telDist');
+            if (telLat) telLat.textContent = '---.----';
+            if (telLon) telLon.textContent = '---.----';
+            if (telAlt) telAlt.textContent = '--- km';
+            if (telEl) telEl.textContent = '--.-';
+            if (telAz) telAz.textContent = '---.-';
+            if (telDist) telDist.textContent = '---- km';
+        }
+
         async function fetchCurrentTelemetry() {
             const lat = parseFloat(document.getElementById('obsLat')?.value);
             const lon = parseFloat(document.getElementById('obsLon')?.value);
diff --git a/utils/satnogs.py b/utils/satnogs.py
index f97841c..b195971 100644
--- a/utils/satnogs.py
+++ b/utils/satnogs.py
@@ -28,6 +28,63 @@ _prefetch_started = False
 _SATNOGS_URL = "https://db.satnogs.org/api/transmitters/?format=json"
 _REQUEST_TIMEOUT = 6  # seconds
 
+_BUILTIN_TRANSMITTERS: dict[int, list[dict]] = {
+    25544: [
+        {
+            "description": "APRS digipeater",
+            "downlink_low": 145.825,
+            "downlink_high": 145.825,
+            "uplink_low": None,
+            "uplink_high": None,
+            "mode": "FM AX.25",
+            "baud": 1200,
+            "status": "active",
+            "type": "beacon",
+            "service": "Packet",
+        },
+        {
+            "description": "SSTV events",
+            "downlink_low": 145.800,
+            "downlink_high": 145.800,
+            "uplink_low": None,
+            "uplink_high": None,
+            "mode": "FM",
+            "baud": None,
+            "status": "active",
+            "type": "image",
+            "service": "SSTV",
+        },
+    ],
+    57166: [
+        {
+            "description": "Meteor LRPT weather downlink",
+            "downlink_low": 137.900,
+            "downlink_high": 137.900,
+            "uplink_low": None,
+            "uplink_high": None,
+            "mode": "LRPT",
+            "baud": 72000,
+            "status": "active",
+            "type": "image",
+            "service": "Weather",
+        },
+    ],
+    59051: [
+        {
+            "description": "Meteor LRPT weather downlink",
+            "downlink_low": 137.900,
+            "downlink_high": 137.900,
+            "uplink_low": None,
+            "uplink_high": None,
+            "mode": "LRPT",
+            "baud": 72000,
+            "status": "active",
+            "type": "image",
+            "service": "Weather",
+        },
+    ],
+}
+
 
 # ---------------------------------------------------------------------------
 # Internal helpers
@@ -125,10 +182,12 @@ def get_transmitters(norad_id: int) -> list[dict]:
     with _fetch_lock:
         age = time.time() - _fetched_at
         if not _transmitters or age > _CACHE_TTL:
-            _transmitters = fetch_transmitters()
-            _fetched_at = time.time()
+            fetched = fetch_transmitters()
+            if fetched:
+                _transmitters = fetched
+                _fetched_at = time.time()
 
-        return _transmitters.get(int(norad_id), [])
+        return _transmitters.get(int(norad_id), _BUILTIN_TRANSMITTERS.get(int(norad_id), []))
 
 
 def refresh_transmitters() -> int:
@@ -141,8 +200,10 @@ def refresh_transmitters() -> int:
     global _transmitters, _fetched_at  # noqa: PLW0603
 
     with _fetch_lock:
-        _transmitters = fetch_transmitters()
-        _fetched_at = time.time()
+        fetched = fetch_transmitters()
+        if fetched:
+            _transmitters = fetched
+            _fetched_at = time.time()
         return len(_transmitters)