diff --git a/README.md b/README.md
index 04297db..82cebac 100644
--- a/README.md
+++ b/README.md
@@ -224,8 +224,9 @@ without logging out.
   positions are propagated from the cached ephemeris, then smoothly interpolated at 10 FPS.
 - The 3D Earth tab includes a `RINEX Guncelle` button for an immediate manual refresh. Its status
   line shows the system-local time of the last successful download or cache load.
-- Complete UART channel snapshots such as `tracked satellites=5 prns=[...]` replace the previous
-  connected-PRN set, so satellites that were lost no longer remain green.
+- Complete UART channel snapshots such as `tracked satellites=5 prn_indices=[...]` replace the
+  previous connected-PRN set, so satellites that were lost no longer remain green. Firmware
+  channel indices are zero-based and are normalized for display (`0` is GPS PRN `G01`).
 - RINEX text is parsed once per download and retained as compact ephemeris records. The static
   globe is cached between camera changes, reducing CPU and allocation load during orbit animation.
 - The globe uses an embedded Natural Earth coastline mask with terrain-like land colouring,
diff --git a/src/LocationParser.cpp b/src/LocationParser.cpp
index f60ff53..ff9940a 100644
--- a/src/LocationParser.cpp
+++ b/src/LocationParser.cpp
@@ -234,10 +234,11 @@ QSet<QString> LocationParser::parseGpsPrns(const QString &line)
     QSet<QString> result;
     const auto addPrn = [&result](QString value, bool zeroBased = false) {
         value = value.trimmed().toUpper();
-        if (value.startsWith(QLatin1Char('G'))) value.remove(0, 1);
+        const bool explicitGpsPrn = value.startsWith(QLatin1Char('G'));
+        if (explicitGpsPrn) value.remove(0, 1);
         bool ok = false;
         int number = value.toInt(&ok);
-        if (ok && zeroBased) ++number;
+        if (ok && zeroBased && !explicitGpsPrn) ++number;
         if (ok && number >= 1 && number <= 63) {
             result.insert(QStringLiteral("G%1").arg(number, 2, 10, QLatin1Char('0')));
         }
@@ -249,18 +250,31 @@ QSet<QString> LocationParser::parseGpsPrns(const QString &line)
     auto gpsMatches = gpsToken.globalMatch(line);
     while (gpsMatches.hasNext()) addPrn(gpsMatches.next().captured(QStringLiteral("prn")));
 
-    static const QRegularExpression labeledList(
-        QStringLiteral(R"((?<label>\bPRNS?\b|\bSVS?\b|\bSVNS?\b|\bSVIDS?\b)\s*(?:=|:|->)?\s*[\[(]?\s*(?<list>(?:G?\d{1,2})(?:\s*[,;/| ]\s*G?\d{1,2})*)\s*[\])]?)"),
+    // Current firmware versions called their zero-based hardware channel values
+    // "prns" in complete tracking snapshots. Keep accepting those messages while
+    // newer firmware uses the unambiguous "prn_indices" label.
+    static const QRegularExpression legacyTrackingIndices(
+        QStringLiteral(R"(\btracked\s+satellites\s*=\s*\d+\s+prns?\s*=)"),
         QRegularExpression::CaseInsensitiveOption);
-    static const QRegularExpression number(QStringLiteral(R"(G?(\d{1,2}))"),
+    const bool legacyZeroBasedPrns = legacyTrackingIndices.match(line).hasMatch();
+
+    static const QRegularExpression labeledList(
+        QStringLiteral(R"((?<label>\bPRN[_ -]?INDICES\b|\bPRNS?\b|\bSVS?\b|\bSVNS?\b|\bSVIDS?\b)\s*(?:=|:|->)?\s*[\[(]?\s*(?<list>(?:G?\d{1,2})(?:\s*[,;/| ]\s*G?\d{1,2})*)\s*[\])]?)"),
+        QRegularExpression::CaseInsensitiveOption);
+    static const QRegularExpression number(QStringLiteral(R"(G?\d{1,2})"),
                                             QRegularExpression::CaseInsensitiveOption);
     auto listMatches = labeledList.globalMatch(line);
     while (listMatches.hasNext()) {
         const QRegularExpressionMatch listMatch = listMatches.next();
-        const bool zeroBased = listMatch.captured(QStringLiteral("label")).startsWith(
-            QStringLiteral("SVN"), Qt::CaseInsensitive);
+        QString label = listMatch.captured(QStringLiteral("label")).toUpper();
+        label.remove(QLatin1Char('_'));
+        label.remove(QLatin1Char('-'));
+        label.remove(QLatin1Char(' '));
+        const bool zeroBased = label.startsWith(QStringLiteral("SVN"))
+            || label == QStringLiteral("PRNINDICES")
+            || (legacyZeroBasedPrns && label.startsWith(QStringLiteral("PRN")));
         auto values = number.globalMatch(listMatch.captured(QStringLiteral("list")));
-        while (values.hasNext()) addPrn(values.next().captured(1), zeroBased);
+        while (values.hasNext()) addPrn(values.next().captured(0), zeroBased);
     }
     return result;
 }
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index c63636f..fe21657 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -520,7 +520,7 @@ void MainWindow::handleSerialLine(const QString &line)
         QRegularExpression::CaseInsensitiveOption);
     static const QRegularExpression trackingSnapshotRegex(
         QStringLiteral(
-            R"(\btracked\s+satellites\s*=\s*\d+\s+(?:prns?|svns?)\s*=\s*\[[^\]]*\])"),
+            R"(\btracked\s+satellites\s*=\s*\d+\s+(?:prn[_ -]?indices|prns?|svns?)\s*=\s*\[[^\]]*\])"),
         QRegularExpression::CaseInsensitiveOption);
     const bool solveStarted = solveStartRegex.match(line.trimmed()).hasMatch();
     const bool trackingSnapshot = trackingSnapshotRegex.match(line).hasMatch();
diff --git a/tests/main_window_tests.cpp b/tests/main_window_tests.cpp
index c021ff9..b4f0b5e 100644
--- a/tests/main_window_tests.cpp
+++ b/tests/main_window_tests.cpp
@@ -89,13 +89,13 @@ int main(int argc, char **argv)
     assert(sideSplitter != nullptr);
     assert(sideSplitter->orientation() == Qt::Vertical);
 
-    sendLine(window, QStringLiteral("[TRK] tracked satellites=2 prns=[3,8]"));
+    sendLine(window, QStringLiteral("[TRK] tracked satellites=2 prn_indices=[2,7]"));
     assert(map != nullptr);
     auto *globe = window.findChild<GlobeWidget *>();
     assert(globe != nullptr);
     assert(globe->observedPrns()
            == QSet<QString>({QStringLiteral("G03"), QStringLiteral("G08")}));
-    sendLine(window, QStringLiteral("[TRK] tracked satellites=1 prns=[14]"));
+    sendLine(window, QStringLiteral("[TRK] tracked satellites=1 prn_indices=[13]"));
     assert(globe->observedPrns() == QSet<QString>({QStringLiteral("G14")}));
 
     assert(QMetaObject::invokeMethod(map, "referenceLocationSelected", Qt::DirectConnection,
diff --git a/tests/parser_tests.cpp b/tests/parser_tests.cpp
index 7b3e7a3..b6994dd 100644
--- a/tests/parser_tests.cpp
+++ b/tests/parser_tests.cpp
@@ -186,6 +186,25 @@ int main(int argc, char **argv)
         assert(prns == QSet<QString>({QStringLiteral("G01"), QStringLiteral("G32")}));
     }
 
+    {
+        const QSet<QString> prns = LocationParser::parseGpsPrns(
+            QStringLiteral("[TRK] tracked satellites=3 prn_indices=[0,7,31]"));
+        assert(prns == QSet<QString>({QStringLiteral("G01"), QStringLiteral("G08"),
+                                     QStringLiteral("G32")}));
+    }
+
+    {
+        const QSet<QString> prns = LocationParser::parseGpsPrns(
+            QStringLiteral("[TRK] tracked satellites=2 prns=[0,7]"));
+        assert(prns == QSet<QString>({QStringLiteral("G01"), QStringLiteral("G08")}));
+    }
+
+    {
+        const QSet<QString> prns = LocationParser::parseGpsPrns(
+            QStringLiteral("[TRK] tracked satellites=2 prn_indices=[0,G08]"));
+        assert(prns == QSet<QString>({QStringLiteral("G01"), QStringLiteral("G08")}));
+    }
+
     {
         const auto parsed = LocationParser::parseLine(QStringLiteral(
             "[OK] [NAV] DOP GDOP=7.0907891622 PDOP=5.6333862175 "