diff --git a/CMakeLists.txt b/CMakeLists.txt
index d4cb237..f34527c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,7 +48,7 @@ endif()
 
 qt_add_resources(location_plotter "app_resources"
     PREFIX "/"
-    FILES resources/ankasys-logo.png resources/land-110m.json
+    FILES resources/ankasys-logo.png resources/land-110m.json resources/bluemarble-2048.png
 )
 
 if(UNIX AND NOT APPLE)
@@ -72,6 +72,20 @@ target_compile_options(location_parser_tests PRIVATE
 )
 add_test(NAME location_parser_tests COMMAND location_parser_tests)
 
+add_executable(location_map_widget_tests
+    tests/map_widget_tests.cpp
+    src/MapWidget.cpp
+    src/MapWidget.h
+    src/TelemetryPoint.h
+)
+target_link_libraries(location_map_widget_tests PRIVATE Qt6::Core Qt6::Widgets Qt6::Network)
+target_compile_options(location_map_widget_tests PRIVATE
+    $<$<CXX_COMPILER_ID:GNU,Clang,AppleClang>:-UNDEBUG>
+)
+add_test(NAME location_map_widget_tests COMMAND location_map_widget_tests)
+set_tests_properties(location_map_widget_tests PROPERTIES
+    ENVIRONMENT "QT_QPA_PLATFORM=offscreen;XDG_CACHE_HOME=/tmp/location-plotter-map-test-cache")
+
 add_executable(location_main_window_tests
     tests/main_window_tests.cpp
     src/LocationParser.cpp
@@ -100,7 +114,7 @@ target_compile_options(location_main_window_tests PRIVATE
 )
 qt_add_resources(location_main_window_tests "test_app_resources"
     PREFIX "/"
-    FILES resources/ankasys-logo.png resources/land-110m.json
+    FILES resources/ankasys-logo.png resources/land-110m.json resources/bluemarble-2048.png
 )
 if(UNIX AND NOT APPLE)
     target_compile_definitions(location_main_window_tests PRIVATE LOCATION_PLOTTER_LINUX_SERIAL=1)
diff --git a/README.md b/README.md
index 0ec0406..e4d0304 100644
--- a/README.md
+++ b/README.md
@@ -232,6 +232,8 @@ without logging out.
   (10 degrees by default, press Enter after typing);
   satellites inside the mask get a cyan sight line and halo. Incoming positions update the
   receiver marker without resetting a globe orientation chosen by dragging.
+- The globe surface uses NASA/GSFC Scientific Visualization Studio's 2048x1024 Blue Marble
+  mosaic (NASA SVS visualization 2915), projected locally without a runtime network request.
 - RINEX download starts at every launch, repeats every 15 minutes, and falls back through the
   previous two UTC days if today's stream file is unavailable. Current and next-minute satellite
   positions are propagated from the cached ephemeris, then smoothly interpolated at 10 FPS.
diff --git a/resources/bluemarble-2048.png b/resources/bluemarble-2048.png
new file mode 100644
index 0000000..2ee1518
Binary files /dev/null and b/resources/bluemarble-2048.png differ
diff --git a/src/GlobeWidget.cpp b/src/GlobeWidget.cpp
index 6b65e5d..ab82880 100644
--- a/src/GlobeWidget.cpp
+++ b/src/GlobeWidget.cpp
@@ -1,12 +1,14 @@
 #include "GlobeWidget.h"
 
 #include <QLinearGradient>
+#include <QDateTime>
 #include <QHash>
 #include <QFile>
 #include <QJsonArray>
 #include <QJsonDocument>
 #include <QJsonObject>
 #include <QMouseEvent>
+#include <QNativeGestureEvent>
 #include <QPainter>
 #include <QPainterPath>
 #include <QPolygonF>
@@ -185,6 +187,15 @@ const QImage &landMask()
     return mask;
 }
 
+const QImage &blueMarbleTexture()
+{
+    static const QImage texture = [] {
+        QImage image(QStringLiteral(":/resources/bluemarble-2048.png"));
+        return image.convertToFormat(QImage::Format_RGB32);
+    }();
+    return texture;
+}
+
 bool maskIsLand(double longitude, double latitude)
 {
     const QImage &mask = landMask();
@@ -354,14 +365,18 @@ void GlobeWidget::paintEvent(QPaintEvent *)
     painter.setRenderHint(QPainter::Antialiasing, true);
 
     const qreal devicePixelRatio = devicePixelRatioF();
+    const qint64 lightingMinute =
+        QDateTime::currentDateTimeUtc().toSecsSinceEpoch() / 60;
     if (m_staticLayer.isNull() || m_staticLayerSize != size()
         || !qFuzzyCompare(m_staticLayerDevicePixelRatio, devicePixelRatio)
         || m_staticLayerYaw != m_yaw || m_staticLayerPitch != m_pitch
-        || m_staticLayerZoom != m_zoom) {
+        || m_staticLayerZoom != m_zoom
+        || m_staticLayerLightingMinute != lightingMinute) {
         rebuildStaticLayer();
     }
     painter.drawPixmap(0, 0, m_staticLayer);
 
+    drawSatelliteCoverage(painter);
     if (m_hasReceiver) drawVisibilityCone(painter);
     if (m_hasReceiver) drawReceiver(painter);
     const int visibleCount = drawSatellites(painter);
@@ -454,10 +469,26 @@ void GlobeWidget::rebuildStaticLayer()
     QPainterPath sphereClip;
     sphereClip.addEllipse(center, radius, radius);
     painter.setClipPath(sphereClip);
-    drawContinents(painter);
+    drawBlueMarble(painter);
     drawGraticule(painter);
     painter.restore();
 
+    // A subtle limb shadow and ocean highlight add depth without hiding the
+    // geographic texture or telemetry overlays.
+    painter.save();
+    QPainterPath lightingClip;
+    lightingClip.addEllipse(center, radius, radius);
+    painter.setClipPath(lightingClip);
+    QRadialGradient limb(center - QPointF(radius * .30, radius * .34), radius * 1.30);
+    limb.setColorAt(0.0, QColor(255, 255, 255, 18));
+    limb.setColorAt(0.50, QColor(70, 175, 225, 5));
+    limb.setColorAt(0.82, QColor(0, 8, 20, 35));
+    limb.setColorAt(1.0, QColor(0, 3, 12, 155));
+    painter.setPen(Qt::NoPen);
+    painter.setBrush(limb);
+    painter.drawEllipse(center, radius, radius);
+    painter.restore();
+
     for (int i = 0; i < 3; ++i) drawOrbit(painter, 55.0 + i * 1.8, i * 61.0 + 12.0);
     painter.end();
 
@@ -467,6 +498,107 @@ void GlobeWidget::rebuildStaticLayer()
     m_staticLayerYaw = m_yaw;
     m_staticLayerPitch = m_pitch;
     m_staticLayerZoom = m_zoom;
+    m_staticLayerLightingMinute =
+        QDateTime::currentDateTimeUtc().toSecsSinceEpoch() / 60;
+}
+
+void GlobeWidget::drawBlueMarble(QPainter &painter) const
+{
+    const QImage &source = blueMarbleTexture();
+    if (source.isNull()) {
+        drawContinents(painter);
+        return;
+    }
+
+    const double radius = std::min(width(), height()) * 0.255 * m_zoom;
+    // Interactive rotation favors latency; mouse release immediately causes
+    // a full Retina-quality rebuild. Satellite animation frames reuse the
+    // cached texture and therefore do not repeat this projection work.
+    const double pixelRatio = m_dragging ? std::min(devicePixelRatioF(), 1.0)
+                                         : std::min(devicePixelRatioF(), 2.0);
+    const int textureSize = m_dragging
+        ? std::clamp(static_cast<int>(std::ceil(radius * 2.0 * pixelRatio)), 280, 650)
+        : std::clamp(static_cast<int>(std::ceil(radius * 2.0 * pixelRatio)), 420, 1200);
+    const QPointF center(width() * 0.5, height() * 0.52);
+    const QRectF target(center.x() - radius, center.y() - radius,
+                        radius * 2.0, radius * 2.0);
+    const QDateTime nowUtc = QDateTime::currentDateTimeUtc();
+    const qint64 lightingMinute = nowUtc.toSecsSinceEpoch() / 60;
+    if (!m_landTexture.isNull() && m_landTexture.width() == textureSize
+        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch
+        && m_landTextureLightingMinute == lightingMinute) {
+        painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+        painter.drawImage(target, m_landTexture);
+        return;
+    }
+
+    QImage globe(textureSize, textureSize, QImage::Format_ARGB32_Premultiplied);
+    globe.fill(Qt::transparent);
+    const double cy = std::cos(m_yaw);
+    const double sy = std::sin(m_yaw);
+    const double cp = std::cos(m_pitch);
+    const double sp = std::sin(m_pitch);
+    const double utcHours = nowUtc.time().msecsSinceStartOfDay() / 3600000.0;
+    const double declination = 23.44 * std::sin(
+        2.0 * Pi * (284.0 + nowUtc.date().dayOfYear()) / 365.25);
+    const Vec3 sun = globeVector(declination, (12.0 - utcHours) * 15.0);
+    const Vec3 camera {sy * cp, cy * cp, -sp};
+    const double halfLength = std::sqrt(std::pow(sun.x + camera.x, 2.0)
+        + std::pow(sun.y + camera.y, 2.0) + std::pow(sun.z + camera.z, 2.0));
+    const Vec3 halfVector {(sun.x + camera.x) / halfLength,
+                           (sun.y + camera.y) / halfLength,
+                           (sun.z + camera.z) / halfLength};
+
+    for (int py = 0; py < textureSize; ++py) {
+        QRgb *destination = reinterpret_cast<QRgb *>(globe.scanLine(py));
+        const double screenZ = -((py + 0.5) / textureSize * 2.0 - 1.0);
+        for (int px = 0; px < textureSize; ++px) {
+            const double screenX = (px + 0.5) / textureSize * 2.0 - 1.0;
+            const double radiusSquared = screenX * screenX + screenZ * screenZ;
+            if (radiusSquared > 1.0) continue;
+            const double depth = std::sqrt(1.0 - radiusSquared);
+            const double yawY = cp * depth + sp * screenZ;
+            const double worldZ = -sp * depth + cp * screenZ;
+            const double worldX = cy * screenX + sy * yawY;
+            const double worldY = -sy * screenX + cy * yawY;
+            const double latitude = std::asin(std::clamp(worldZ, -1.0, 1.0));
+            const double longitude = std::atan2(worldY, worldX);
+            int sourceX = static_cast<int>((longitude / (2.0 * Pi) + 0.5) * source.width());
+            sourceX = (sourceX % source.width() + source.width()) % source.width();
+            const int sourceY = std::clamp(static_cast<int>((0.5 - latitude / Pi)
+                                               * source.height()), 0, source.height() - 1);
+            const QRgb sample = reinterpret_cast<const QRgb *>(source.constScanLine(sourceY))[sourceX];
+
+            double red = qRed(sample);
+            double green = qGreen(sample);
+            double blue = qBlue(sample);
+            const double solarDot = worldX * sun.x + worldY * sun.y + worldZ * sun.z;
+            const double daylight = smoothStep(-0.10, 0.07, solarDot);
+            const double diffuse = 0.16 + 0.84 * std::max(0.0, solarDot);
+            const bool ocean = blue > green * 1.18 && blue > red * 1.35;
+            if (ocean) {
+                const double halfDot = std::max(0.0, worldX * halfVector.x
+                    + worldY * halfVector.y + worldZ * halfVector.z);
+                const double specular = std::pow(halfDot, 80.0) * daylight * 115.0;
+                red += specular;
+                green += specular;
+                blue += specular * 0.92;
+            }
+            const double limb = smoothStep(0.02, 0.34, depth);
+            const double lighting = (0.08 + diffuse * 0.92) * (0.45 + limb * 0.55);
+            destination[px] = qRgba(
+                std::clamp(static_cast<int>(red * lighting), 0, 255),
+                std::clamp(static_cast<int>(green * lighting), 0, 255),
+                std::clamp(static_cast<int>(blue * lighting), 0, 255), 255);
+        }
+    }
+
+    m_landTexture = globe;
+    m_landTextureYaw = m_yaw;
+    m_landTexturePitch = m_pitch;
+    m_landTextureLightingMinute = lightingMinute;
+    painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+    painter.drawImage(target, m_landTexture);
 }
 
 void GlobeWidget::drawContinents(QPainter &painter) const
@@ -479,8 +611,11 @@ void GlobeWidget::drawContinents(QPainter &painter) const
     const QPointF center(width() * 0.5, height() * 0.52);
     const QRectF target(center.x() - radius, center.y() - radius,
                         radius * 2.0, radius * 2.0);
+    const QDateTime nowUtc = QDateTime::currentDateTimeUtc();
+    const qint64 lightingMinute = nowUtc.toSecsSinceEpoch() / 60;
     if (!m_landTexture.isNull() && m_landTexture.width() == textureSize
-        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch) {
+        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch
+        && m_landTextureLightingMinute == lightingMinute) {
         painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
         painter.drawImage(target, m_landTexture);
         return;
@@ -492,6 +627,18 @@ void GlobeWidget::drawContinents(QPainter &painter) const
     const double sy = std::sin(m_yaw);
     const double cp = std::cos(m_pitch);
     const double sp = std::sin(m_pitch);
+    const double utcHours = nowUtc.time().msecsSinceStartOfDay() / 3600000.0;
+    const double solarDeclination = 23.44 * std::sin(
+        2.0 * Pi * (284.0 + nowUtc.date().dayOfYear()) / 365.25);
+    const double subsolarLongitude = (12.0 - utcHours) * 15.0;
+    const Vec3 sun = globeVector(solarDeclination, subsolarLongitude);
+    const Vec3 camera {sy * cp, cy * cp, -sp};
+    const double halfLength = std::sqrt(
+        std::pow(sun.x + camera.x, 2.0) + std::pow(sun.y + camera.y, 2.0)
+        + std::pow(sun.z + camera.z, 2.0));
+    const Vec3 halfVector {(sun.x + camera.x) / halfLength,
+                           (sun.y + camera.y) / halfLength,
+                           (sun.z + camera.z) / halfLength};
     for (int py = 0; py < textureSize; ++py) {
         QRgb *scanLine = reinterpret_cast<QRgb *>(land.scanLine(py));
         const double screenZ = -((py + 0.5) / textureSize * 2.0 - 1.0);
@@ -512,16 +659,37 @@ void GlobeWidget::drawContinents(QPainter &painter) const
                 || maskIsLand(longitude - 0.55, latitude)
                 || maskIsLand(longitude, latitude + 0.55)
                 || maskIsLand(longitude, latitude - 0.55);
+            const double cloudNoise = 0.50
+                + 0.24 * std::sin(longitude * Pi / 22.0 + latitude * Pi / 19.0)
+                + 0.18 * std::sin(longitude * Pi / 7.0 - latitude * Pi / 13.0)
+                + 0.12 * std::cos(longitude * Pi / 3.7 + latitude * Pi / 8.0);
+            const double cloud = smoothStep(0.72, 0.94, cloudNoise)
+                * smoothStep(0.03, 0.25, depth);
+            const double solarDot = worldX * sun.x + worldY * sun.y + worldZ * sun.z;
+            const double daylight = smoothStep(-0.11, 0.08, solarDot);
+            const double diffuse = 0.12 + 0.88 * std::max(0.0, solarDot);
             if (!onLand) {
-                if (nearLand) {
-                    const int alpha = static_cast<int>(65.0 * std::clamp(depth * 1.5, 0.0, 1.0));
-                    scanLine[px] = qRgba(33, 151, 174, alpha);
-                }
+                const double oceanPattern = 0.5 + 0.25 * std::sin(longitude * Pi / 31.0)
+                    + 0.18 * std::cos(latitude * Pi / 17.0 + longitude * Pi / 47.0);
+                double red = nearLand ? 18.0 : 3.0 + oceanPattern * 5.0;
+                double green = nearLand ? 104.0 : 32.0 + oceanPattern * 16.0;
+                double blue = nearLand ? 132.0 : 72.0 + oceanPattern * 26.0;
+                const double halfDot = std::max(0.0, worldX * halfVector.x
+                    + worldY * halfVector.y + worldZ * halfVector.z);
+                const double specular = std::pow(halfDot, 72.0) * daylight * 150.0;
+                const double shade = 0.18 + diffuse * 0.82;
+                red = red * shade + specular;
+                green = green * shade + specular;
+                blue = blue * shade + specular * 0.92;
+                red = red * (1.0 - cloud * 0.58) + 226.0 * cloud * 0.58;
+                green = green * (1.0 - cloud * 0.58) + 237.0 * cloud * 0.58;
+                blue = blue * (1.0 - cloud * 0.58) + 243.0 * cloud * 0.58;
+                scanLine[px] = qRgba(std::clamp(static_cast<int>(red), 0, 255),
+                                     std::clamp(static_cast<int>(green), 0, 255),
+                                     std::clamp(static_cast<int>(blue), 0, 255), 248);
                 continue;
             }
 
-            const double light = std::clamp(0.30 + 0.70
-                * (0.35 - screenX * 0.38 + screenZ * 0.48 + depth * 0.38), 0.18, 1.0);
             const double lon = longitude * Pi / 180.0;
             const double lat = latitude * Pi / 180.0;
             const double broadRelief = 0.50 + 0.24 * std::sin(lon * 5.0 + lat * 2.2)
@@ -550,31 +718,110 @@ void GlobeWidget::drawContinents(QPainter &painter) const
             red = red * (1.0 - snow) + 224.0 * snow;
             green = green * (1.0 - snow) + 231.0 * snow;
             blue = blue * (1.0 - snow) + 224.0 * snow;
+            red = red * (1.0 - cloud * 0.62) + 232.0 * cloud * 0.62;
+            green = green * (1.0 - cloud * 0.62) + 241.0 * cloud * 0.62;
+            blue = blue * (1.0 - cloud * 0.62) + 244.0 * cloud * 0.62;
 
             const bool coast = !maskIsLand(longitude + 0.55, latitude)
                 || !maskIsLand(longitude - 0.55, latitude)
                 || !maskIsLand(longitude, latitude + 0.55)
                 || !maskIsLand(longitude, latitude - 0.55);
-            const double shade = light * (0.86 + relief * 0.14);
+            const double shade = (0.15 + diffuse * 0.85) * (0.86 + relief * 0.14);
             if (coast) {
                 red += 28.0;
                 green += 31.0;
                 blue += 18.0;
             }
+            const double settlementNoise = 0.5 + 0.28 * std::sin(lon * 41.0 + lat * 19.0)
+                + 0.22 * std::cos(lon * 73.0 - lat * 31.0);
+            const double cityLights = smoothStep(0.82, 0.98, settlementNoise)
+                * (1.0 - daylight) * smoothStep(68.0, 42.0, std::abs(latitude));
             scanLine[px] = qRgba(
-                std::clamp(static_cast<int>(red * shade), 0, 255),
-                std::clamp(static_cast<int>(green * shade), 0, 255),
-                std::clamp(static_cast<int>(blue * shade), 0, 255), 238);
+                std::clamp(static_cast<int>(red * shade + cityLights * 235.0), 0, 255),
+                std::clamp(static_cast<int>(green * shade + cityLights * 155.0), 0, 255),
+                std::clamp(static_cast<int>(blue * shade + cityLights * 52.0), 0, 255), 248);
         }
     }
 
     m_landTexture = land;
     m_landTextureYaw = m_yaw;
     m_landTexturePitch = m_pitch;
+    m_landTextureLightingMinute = lightingMinute;
     painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
     painter.drawImage(target, m_landTexture);
 }
 
+void GlobeWidget::drawSatelliteCoverage(QPainter &painter) const
+{
+    if (m_satellites.isEmpty()) return;
+
+    constexpr double EarthRadiusMeters = 6378137.0;
+    const double earthRadiusPixels = std::min(width(), height()) * 0.255 * m_zoom;
+    const double elevation = m_elevationMaskDegrees * Pi / 180.0;
+
+    for (const SatellitePosition &satellite : m_satellites) {
+        const double orbitRadius = std::sqrt(satellite.x * satellite.x
+                                             + satellite.y * satellite.y
+                                             + satellite.z * satellite.z);
+        if (orbitRadius <= EarthRadiusMeters) continue;
+
+        const Vec3 normal {satellite.x / orbitRadius, satellite.y / orbitRadius,
+                           satellite.z / orbitRadius};
+        const double footprintAngle = std::acos(std::clamp(
+            EarthRadiusMeters / orbitRadius * std::cos(elevation), -1.0, 1.0)) - elevation;
+        Vec3 reference = std::abs(normal.z) < 0.88
+            ? Vec3{0.0, 0.0, 1.0} : Vec3{1.0, 0.0, 0.0};
+        Vec3 tangentA {
+            reference.y * normal.z - reference.z * normal.y,
+            reference.z * normal.x - reference.x * normal.z,
+            reference.x * normal.y - reference.y * normal.x
+        };
+        const double tangentLength = std::sqrt(tangentA.x * tangentA.x
+                                                + tangentA.y * tangentA.y
+                                                + tangentA.z * tangentA.z);
+        if (tangentLength <= 0.0) continue;
+        tangentA = {tangentA.x / tangentLength, tangentA.y / tangentLength,
+                    tangentA.z / tangentLength};
+        const Vec3 tangentB {
+            normal.y * tangentA.z - normal.z * tangentA.y,
+            normal.z * tangentA.x - normal.x * tangentA.z,
+            normal.x * tangentA.y - normal.y * tangentA.x
+        };
+
+        const bool tracked = m_observedPrns.contains(satellite.prn);
+        QColor coverageColor = tracked ? QColor(69, 232, 157, 78)
+                                       : QColor(83, 188, 230, 25);
+        painter.setPen(QPen(coverageColor, tracked ? 1.15 : 0.65, Qt::DashLine));
+        painter.setBrush(Qt::NoBrush);
+        QPainterPath visibleSegments;
+        bool drawing = false;
+        constexpr int Segments = 72;
+        for (int segment = 0; segment <= Segments; ++segment) {
+            const double angle = 2.0 * Pi * segment / Segments;
+            const Vec3 tangent {
+                tangentA.x * std::cos(angle) + tangentB.x * std::sin(angle),
+                tangentA.y * std::cos(angle) + tangentB.y * std::sin(angle),
+                tangentA.z * std::cos(angle) + tangentB.z * std::sin(angle)
+            };
+            const Vec3 surface {
+                normal.x * std::cos(footprintAngle) + tangent.x * std::sin(footprintAngle),
+                normal.y * std::cos(footprintAngle) + tangent.y * std::sin(footprintAngle),
+                normal.z * std::cos(footprintAngle) + tangent.z * std::sin(footprintAngle)
+            };
+            const ProjectedPoint point = project(surface.x, surface.y, surface.z,
+                                                 earthRadiusPixels * 1.006);
+            if (point.depth >= -0.015) {
+                if (!drawing) visibleSegments.moveTo(point.point);
+                else visibleSegments.lineTo(point.point);
+                drawing = true;
+            } else {
+                drawing = false;
+            }
+        }
+        painter.drawPath(visibleSegments);
+    }
+}
+
 void GlobeWidget::drawStars(QPainter &painter) const
 {
     painter.setPen(Qt::NoPen);
@@ -591,6 +838,10 @@ void GlobeWidget::drawStars(QPainter &painter) const
 void GlobeWidget::drawGraticule(QPainter &painter) const
 {
     const double radius = std::min(width(), height()) * 0.255 * m_zoom;
+    // Paths are open grid lines. Inheriting the radial Earth brush makes
+    // QPainter implicitly close and fill them, which produced the black
+    // rectangular/polygonal artifacts on the globe.
+    painter.setBrush(Qt::NoBrush);
     painter.setPen(QPen(QColor(100, 193, 221, 48), 0.8));
     for (int latitude = -60; latitude <= 60; latitude += 30) {
         QPainterPath path;
@@ -707,14 +958,10 @@ void GlobeWidget::drawVisibilityCone(QPainter &painter) const
                                earthRadiusPixels * displayOrbitRatio));
     }
 
-    painter.setPen(Qt::NoPen);
-    for (int i = 0; i < Segments; ++i) {
-        const double averageDepth = (apex.depth + ring[i].depth + ring[i + 1].depth) / 3.0;
-        const int alpha = averageDepth >= 0.0 ? 18 : 7;
-        painter.setBrush(QColor(48, 207, 218, alpha));
-        painter.drawPolygon(QPolygonF{apex.point, ring[i].point, ring[i + 1].point});
-    }
-
+    // Do not fill the projected cone with a triangle fan. When part of the
+    // ring is behind the globe that fan self-intersects and produces dark
+    // rectangular/polygonal artifacts over the Earth texture. The boundary,
+    // spokes and sight lines communicate the same mask without obscuring it.
     QPainterPath boundary;
     boundary.moveTo(ring.first().point);
     for (int i = 1; i < ring.size(); ++i) boundary.lineTo(ring[i].point);
@@ -864,7 +1111,26 @@ void GlobeWidget::mouseReleaseEvent(QMouseEvent *event)
 
 void GlobeWidget::wheelEvent(QWheelEvent *event)
 {
-    m_zoom = std::clamp(m_zoom + event->angleDelta().y() / 1200.0, 0.72, 1.28);
+    const QPoint pixelDelta = event->pixelDelta();
+    const double delta = !pixelDelta.isNull()
+        ? pixelDelta.y() / 420.0
+        : event->angleDelta().y() / 1200.0;
+    if (qFuzzyIsNull(delta)) return;
+    m_zoom = std::clamp(m_zoom + delta, 0.62, 1.42);
     update();
     event->accept();
 }
+
+bool GlobeWidget::event(QEvent *event)
+{
+    if (event->type() == QEvent::NativeGesture) {
+        auto *gesture = static_cast<QNativeGestureEvent *>(event);
+        if (gesture->gestureType() == Qt::ZoomNativeGesture) {
+            m_zoom = std::clamp(m_zoom + gesture->value() * 0.85, 0.62, 1.42);
+            update();
+            gesture->accept();
+            return true;
+        }
+    }
+    return QWidget::event(event);
+}
diff --git a/src/GlobeWidget.h b/src/GlobeWidget.h
index 0164b18..896233b 100644
--- a/src/GlobeWidget.h
+++ b/src/GlobeWidget.h
@@ -30,6 +30,7 @@ public slots:
     void setElevationMask(double degrees);
 
 protected:
+    bool event(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
     void mousePressEvent(QMouseEvent *event) override;
     void mouseMoveEvent(QMouseEvent *event) override;
@@ -46,6 +47,8 @@ private:
     void drawStars(QPainter &painter) const;
     void drawOrbit(QPainter &painter, double inclination, double node) const;
     void drawContinents(QPainter &painter) const;
+    void drawBlueMarble(QPainter &painter) const;
+    void drawSatelliteCoverage(QPainter &painter) const;
     void drawVisibilityCone(QPainter &painter) const;
     void drawGraticule(QPainter &painter) const;
     void drawReceiver(QPainter &painter) const;
@@ -63,12 +66,14 @@ private:
     mutable QImage m_landTexture;
     mutable double m_landTextureYaw = 0.0;
     mutable double m_landTexturePitch = 0.0;
+    mutable qint64 m_landTextureLightingMinute = -1;
     QPixmap m_staticLayer;
     QSize m_staticLayerSize;
     qreal m_staticLayerDevicePixelRatio = 0.0;
     double m_staticLayerYaw = 0.0;
     double m_staticLayerPitch = 0.0;
     double m_staticLayerZoom = 0.0;
+    qint64 m_staticLayerLightingMinute = -1;
     QSet<QString> m_observedPrns;
     QString m_status = QStringLiteral("Konum bekleniyor");
     bool m_statusError = false;
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index d197d49..8896946 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -26,14 +26,15 @@
 #include <QHeaderView>
 #include <QLabel>
 #include <QLineEdit>
+#include <QMenuBar>
 #include <QMessageBox>
 #include <QPlainTextEdit>
 #include <QScrollArea>
 #include <QPushButton>
 #include <QRegularExpression>
+#include <QSettings>
 #include <QSpinBox>
 #include <QSplitter>
-#include <QSettings>
 #include <QStatusBar>
 #include <QStyle>
 #include <QTabWidget>
@@ -167,6 +168,7 @@ LocationAnalysis analyzeLocations(const QVector<TelemetryPoint> &points)
 QVector<TelemetryPoint> preferredAnalysisPoints(const QVector<TelemetryPoint> &points)
 {
     QVector<TelemetryPoint> corrected;
+    corrected.reserve(points.size());
     for (const TelemetryPoint &point : points) {
         if (point.source == LocationSource::ImuCorrected) {
             corrected.push_back(point);
@@ -386,6 +388,7 @@ MainWindow::MainWindow(QWidget *parent)
     , m_rinex(new RinexNavigation(this))
 {
     buildUi();
+    buildMenus();
 
     m_locationTimeoutTimer = new QTimer(this);
     m_locationTimeoutTimer->setSingleShot(true);
@@ -395,6 +398,9 @@ MainWindow::MainWindow(QWidget *parent)
     m_uiRefreshTimer->setSingleShot(true);
     m_uiRefreshTimer->setInterval(UiRefreshIntervalMs);
 
+    m_portRefreshTimer = new QTimer(this);
+    m_portRefreshTimer->setInterval(2000);
+
     connect(m_serial, &SerialReader::lineReceived, this, &MainWindow::handleSerialLine);
     connect(m_serial, &SerialReader::statusChanged, this, &MainWindow::handleSerialStatus);
     connect(m_serial, &SerialReader::errorOccurred, this, &MainWindow::handleSerialError);
@@ -434,11 +440,21 @@ MainWindow::MainWindow(QWidget *parent)
     });
     connect(m_locationTimeoutTimer, &QTimer::timeout, this, &MainWindow::handleLocationTimeout);
     connect(m_uiRefreshTimer, &QTimer::timeout, this, &MainWindow::flushUiUpdates);
+    connect(m_portRefreshTimer, &QTimer::timeout, this, [this] {
+        if (!m_serial->isOpen()) refreshSerialPorts();
+    });
+    m_portRefreshTimer->start();
     connect(m_rinex, &RinexNavigation::satelliteMotionUpdated,
             m_globe, &GlobeWidget::setSatelliteMotion);
     connect(m_rinex, &RinexNavigation::statusChanged, this,
             [this](const QString &status, bool error) {
         m_globe->setRinexStatus(status, error);
+        if (m_rinexUpdateButton != nullptr) {
+            m_rinexUpdateButton->setEnabled(!m_rinex->isLoading());
+            m_rinexUpdateButton->setText(m_rinex->isLoading()
+                ? QStringLiteral("RINEX indiriliyor...")
+                : QStringLiteral("RINEX Guncelle"));
+        }
         statusBar()->showMessage(status, error ? 8000 : 4000);
     });
     connect(m_rinex, &RinexNavigation::loadingChanged, this, [this](bool loading) {
@@ -456,6 +472,7 @@ MainWindow::MainWindow(QWidget *parent)
     rinexRefreshTimer->start();
 
     resize(1480, 900);
+    loadSettings();
     setWindowTitle(QStringLiteral("Canli Konum Haritasi"));
 }
 
@@ -463,6 +480,7 @@ void MainWindow::closeEvent(QCloseEvent *event)
 {
     m_replay->stop();
     stopUartLogging();
+    saveSettings();
     QMainWindow::closeEvent(event);
 }
 
@@ -628,20 +646,19 @@ bool MainWindow::loadTelemetryLog(const QString &filePath)
     resetTelemetryState();
     const int replayCapacity = static_cast<int>(std::min<qsizetype>(10000, lines.size()));
     m_maxPointsSpin->setValue(std::max(10, replayCapacity));
-    int parsedLocations = 0;
     for (const QByteArray &rawLine : lines) {
         const QString line = QString::fromUtf8(rawLine).trimmed();
         if (line.isEmpty() || line.startsWith(QLatin1Char('#'))) {
             continue;
         }
-        const auto telemetry = LocationParser::parseLine(line);
-        if (telemetry.has_value() && telemetry->hasLocation()) {
-            ++parsedLocations;
-        }
         handleSerialLine(line);
     }
+    // Replay files do not always include a final "NAV solve done" marker. If
+    // the final latitude/longitude pair is complete, retain it as a fix.
+    commitPendingTelemetry();
     flushUiUpdates();
     m_map->fitToPoints();
+    const int parsedLocations = m_points.size();
     const QString message = QStringLiteral("Replay yuklendi: %1 konum - %2")
         .arg(parsedLocations).arg(filePath);
     m_statusLabel->setText(message);
@@ -754,6 +771,14 @@ void MainWindow::refreshSerialPorts()
     const QString configuredPort = qEnvironmentVariable("LOCATION_PLOTTER_PORT").trimmed();
     const QStringList detectedPorts = detectedSerialPorts();
 
+    if (m_portsInitialized && detectedPorts == m_lastDetectedPorts) {
+        return;
+    }
+    const bool deviceAdded = m_portsInitialized
+        && detectedPorts.size() > m_lastDetectedPorts.size();
+    m_lastDetectedPorts = detectedPorts;
+    m_portsInitialized = true;
+
     m_portCombo->clear();
     for (const QString &port : detectedPorts) {
         m_portCombo->addItem(port);
@@ -774,6 +799,110 @@ void MainWindow::refreshSerialPorts()
         m_portCombo->addItem(selectedPort);
     }
     m_portCombo->setCurrentText(selectedPort);
+    if (deviceAdded) {
+        statusBar()->showMessage(QStringLiteral("Yeni USB UART aygiti algilandi: %1")
+                                     .arg(selectedPort), 4000);
+    }
+}
+
+void MainWindow::buildMenus()
+{
+    auto *fileMenu = menuBar()->addMenu(QStringLiteral("Dosya"));
+    QAction *openAction = fileMenu->addAction(QStringLiteral("Senaryo Logu Ac..."));
+    openAction->setObjectName(QStringLiteral("openLogAction"));
+    openAction->setShortcut(QKeySequence::Open);
+    connect(openAction, &QAction::triggered, this, &MainWindow::openTelemetryLog);
+    QAction *replayAction = fileMenu->addAction(QStringLiteral("UART Log Replay..."));
+    replayAction->setObjectName(QStringLiteral("uartReplayAction"));
+    replayAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+Shift+O")));
+    connect(replayAction, &QAction::triggered, this, &MainWindow::openUartReplay);
+    fileMenu->addSeparator();
+    QAction *quitAction = fileMenu->addAction(QStringLiteral("Cikis"));
+    quitAction->setShortcut(QKeySequence::Quit);
+    connect(quitAction, &QAction::triggered, this, &QWidget::close);
+
+    auto *connectionMenu = menuBar()->addMenu(QStringLiteral("Baglanti"));
+    QAction *listenAction = connectionMenu->addAction(QStringLiteral("Seri Baglantiyi Ac / Kapat"));
+    listenAction->setObjectName(QStringLiteral("toggleSerialAction"));
+    listenAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+K")));
+    connect(listenAction, &QAction::triggered, this, &MainWindow::toggleSerial);
+    QAction *portsAction = connectionMenu->addAction(QStringLiteral("Portlari Yenile"));
+    portsAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+Shift+R")));
+    connect(portsAction, &QAction::triggered, this, [this] {
+        m_portsInitialized = false;
+        refreshSerialPorts();
+    });
+    QAction *rinexAction = connectionMenu->addAction(QStringLiteral("RINEX Guncelle"));
+    rinexAction->setObjectName(QStringLiteral("rinexUpdateAction"));
+    rinexAction->setShortcut(QKeySequence::Refresh);
+    connect(rinexAction, &QAction::triggered, m_rinex, &RinexNavigation::refresh);
+
+    auto *viewMenu = menuBar()->addMenu(QStringLiteral("Gorunum"));
+    QAction *fitAction = viewMenu->addAction(QStringLiteral("Rotayi Haritaya Sigdir"));
+    fitAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+0")));
+    connect(fitAction, &QAction::triggered, m_map, &MapWidget::fitToPoints);
+    QAction *zoomInAction = viewMenu->addAction(QStringLiteral("Yaklastir"));
+    zoomInAction->setShortcut(QKeySequence::ZoomIn);
+    connect(zoomInAction, &QAction::triggered, m_map, &MapWidget::zoomIn);
+    QAction *zoomOutAction = viewMenu->addAction(QStringLiteral("Uzaklastir"));
+    zoomOutAction->setShortcut(QKeySequence::ZoomOut);
+    connect(zoomOutAction, &QAction::triggered, m_map, &MapWidget::zoomOut);
+
+    auto *helpMenu = menuBar()->addMenu(QStringLiteral("Yardim"));
+    QAction *aboutAction = helpMenu->addAction(QStringLiteral("Location Plotter Hakkinda"));
+    connect(aboutAction, &QAction::triggered, this, [this] {
+        QMessageBox::about(this, QStringLiteral("Location Plotter"),
+            QStringLiteral("GNSS telemetri, konum analizi ve RINEX uydu gorunumu\n"
+                           "macOS surumu 0.2.0"));
+    });
+}
+
+void MainWindow::loadSettings()
+{
+    QSettings settings;
+    restoreGeometry(settings.value(QStringLiteral("window/geometry")).toByteArray());
+    if (auto *splitter = findChild<QSplitter *>(QStringLiteral("mainSplitter")))
+        splitter->restoreState(settings.value(QStringLiteral("window/mainSplitter")).toByteArray());
+    if (auto *splitter = findChild<QSplitter *>(QStringLiteral("sideSplitter")))
+        splitter->restoreState(settings.value(QStringLiteral("window/sideSplitter")).toByteArray());
+
+    const QString port = settings.value(QStringLiteral("serial/port")).toString();
+    if (!port.isEmpty()) {
+        if (m_portCombo->findText(port) < 0) m_portCombo->addItem(port);
+        m_portCombo->setCurrentText(port);
+    }
+    m_baudCombo->setCurrentText(settings.value(QStringLiteral("serial/baud"), 115200).toString());
+    m_maxPointsSpin->setValue(settings.value(QStringLiteral("telemetry/maxPoints"), 10).toInt());
+    m_autoFollowCheck->setChecked(settings.value(QStringLiteral("map/autoFollow"), true).toBool());
+    m_showTelemetryCheck->setChecked(settings.value(QStringLiteral("map/showTelemetry"), true).toBool());
+    m_showRecentPointsCheck->setChecked(settings.value(QStringLiteral("map/showRecent"), true).toBool());
+    m_showAverageCheck->setChecked(settings.value(QStringLiteral("map/showAverage"), true).toBool());
+    if (auto *elevation = findChild<QDoubleSpinBox *>(QStringLiteral("elevationMaskSpin")))
+        elevation->setValue(settings.value(QStringLiteral("globe/elevationMask"), 10.0).toDouble());
+    if (auto *tabs = findChild<QTabWidget *>(QStringLiteral("mainViewTabs")))
+        tabs->setCurrentIndex(settings.value(QStringLiteral("window/mainTab"), 0).toInt());
+}
+
+void MainWindow::saveSettings() const
+{
+    QSettings settings;
+    settings.setValue(QStringLiteral("window/geometry"), saveGeometry());
+    if (auto *splitter = findChild<QSplitter *>(QStringLiteral("mainSplitter")))
+        settings.setValue(QStringLiteral("window/mainSplitter"), splitter->saveState());
+    if (auto *splitter = findChild<QSplitter *>(QStringLiteral("sideSplitter")))
+        settings.setValue(QStringLiteral("window/sideSplitter"), splitter->saveState());
+    settings.setValue(QStringLiteral("serial/port"), m_portCombo->currentText().trimmed());
+    settings.setValue(QStringLiteral("serial/baud"), selectedBaudRate());
+    settings.setValue(QStringLiteral("telemetry/maxPoints"), m_maxPointsSpin->value());
+    settings.setValue(QStringLiteral("map/autoFollow"), m_autoFollowCheck->isChecked());
+    settings.setValue(QStringLiteral("map/showTelemetry"), m_showTelemetryCheck->isChecked());
+    settings.setValue(QStringLiteral("map/showRecent"), m_showRecentPointsCheck->isChecked());
+    settings.setValue(QStringLiteral("map/showAverage"), m_showAverageCheck->isChecked());
+    if (auto *elevation = findChild<QDoubleSpinBox *>(QStringLiteral("elevationMaskSpin")))
+        settings.setValue(QStringLiteral("globe/elevationMask"), elevation->value());
+    if (auto *tabs = findChild<QTabWidget *>(QStringLiteral("mainViewTabs")))
+        settings.setValue(QStringLiteral("window/mainTab"), tabs->currentIndex());
+    settings.sync();
 }
 
 void MainWindow::handleSerialLine(const QString &line)
@@ -789,6 +918,14 @@ void MainWindow::handleSerialLine(const QString &line)
     const bool solveStarted = solveStartRegex.match(line.trimmed()).hasMatch();
     const bool trackingSnapshot = trackingSnapshotRegex.match(line).hasMatch();
     if (solveStarted) {
+        // Never combine a coordinate fragment left by the previous navigation
+        // period with fields from the new one. A complete pending fix is still
+        // useful; an incomplete one must be discarded at the period boundary.
+        if (m_pendingTelemetry.hasLocation()) {
+            commitPendingTelemetry();
+        } else {
+            m_pendingTelemetry = {};
+        }
         m_observedPrns.clear();
     }
     const QSet<QString> linePrns = LocationParser::parseGpsPrns(line);
@@ -1012,7 +1149,10 @@ void MainWindow::buildUi()
             background: #23445d;
             border-color: #62b8e8;
         }
-        QPushButton:pressed, QToolButton:pressed { background: #dbeaf6; }
+        QPushButton:pressed, QToolButton:pressed {
+            color: #102333;
+            background: #dbeaf6;
+        }
         QCheckBox { spacing: 7px; color: #d5e0e9; }
         QCheckBox::indicator { width: 17px; height: 17px; }
         QCheckBox::indicator:unchecked {
@@ -1089,7 +1229,7 @@ void MainWindow::buildUi()
 
     m_portCombo = new QComboBox(this);
     m_portCombo->setObjectName(QStringLiteral("portSelector"));
-    m_portCombo->setMinimumWidth(220);
+    m_portCombo->setMinimumWidth(170);
     m_portCombo->setEditable(true);
     m_portCombo->setToolTip(QStringLiteral(
         "USB UART portu. macOS'ta /dev/cu.usb... tercih edilir; /dev/tty.usb... da desteklenir."));
@@ -1124,6 +1264,11 @@ void MainWindow::buildUi()
     m_replayButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
     m_replayButton->setToolTip(QStringLiteral(
         "Kayitli UART verisini GPS ve sensor guncelleme hizlariyla yeniden oynat"));
+    m_rinexUpdateButton = new QPushButton(QStringLiteral("RINEX Guncelle"), this);
+    m_rinexUpdateButton->setObjectName(QStringLiteral("rinexUpdateButton"));
+    m_rinexUpdateButton->setIcon(style()->standardIcon(QStyle::SP_BrowserReload));
+    m_rinexUpdateButton->setToolTip(QStringLiteral(
+        "BKG/IGS arsivinden guncel GPS RINEX navigasyon verisini yeniden indir"));
 
     m_autoFollowCheck = new QCheckBox(QStringLiteral("Kamerayi takip et"), this);
     m_autoFollowCheck->setChecked(true);
@@ -1145,6 +1290,7 @@ void MainWindow::buildUi()
     toolbarLayout->addWidget(m_connectButton);
     toolbarLayout->addWidget(m_openLogButton);
     toolbarLayout->addWidget(m_replayButton);
+    toolbarLayout->addWidget(m_rinexUpdateButton);
     toolbarLayout->addWidget(m_clearButton);
     toolbarLayout->addWidget(m_autoFollowCheck);
     toolbarLayout->addWidget(zoomOutButton);
@@ -1178,7 +1324,7 @@ void MainWindow::buildUi()
     viewTabs->addTab(globeTab, QStringLiteral("3B Dunya · Uydular"));
 
     auto *sidePanel = new QWidget(this);
-    sidePanel->setMinimumWidth(390);
+    sidePanel->setMinimumWidth(330);
     auto *sideOuterLayout = new QVBoxLayout(sidePanel);
     sideOuterLayout->setContentsMargins(8, 0, 0, 0);
     sideOuterLayout->setSpacing(0);
@@ -1381,7 +1527,11 @@ void MainWindow::buildUi()
     connect(m_clearButton, &QPushButton::clicked, this, &MainWindow::clearPoints);
     connect(m_openLogButton, &QPushButton::clicked, this, &MainWindow::openTelemetryLog);
     connect(m_replayButton, &QPushButton::clicked, this, &MainWindow::openUartReplay);
-    connect(refreshPortsButton, &QToolButton::clicked, this, &MainWindow::refreshSerialPorts);
+    connect(m_rinexUpdateButton, &QPushButton::clicked, m_rinex, &RinexNavigation::refresh);
+    connect(refreshPortsButton, &QToolButton::clicked, this, [this] {
+        m_portsInitialized = false;
+        refreshSerialPorts();
+    });
     connect(m_maxPointsSpin, qOverload<int>(&QSpinBox::valueChanged), this,
             &MainWindow::trimToMaxPoints);
     connect(m_autoFollowCheck, &QCheckBox::toggled, m_map, &MapWidget::setAutoFollow);
diff --git a/src/MainWindow.h b/src/MainWindow.h
index cf6ae2e..6b1061c 100644
--- a/src/MainWindow.h
+++ b/src/MainWindow.h
@@ -59,6 +59,9 @@ private slots:
 
 private:
     void buildUi();
+    void buildMenus();
+    void loadSettings();
+    void saveSettings() const;
     void updateConnectionControls();
     void addTelemetryPoint(const ParsedTelemetry &telemetry);
     void refreshTable();
@@ -89,6 +92,7 @@ private:
     QPushButton *m_clearButton = nullptr;
     QPushButton *m_openLogButton = nullptr;
     QPushButton *m_replayButton = nullptr;
+    QPushButton *m_rinexUpdateButton = nullptr;
     QPushButton *m_refreshRinexButton = nullptr;
     QCheckBox *m_autoFollowCheck = nullptr;
     QCheckBox *m_showTelemetryCheck = nullptr;
@@ -113,6 +117,7 @@ private:
     QPlainTextEdit *m_log = nullptr;
     QTimer *m_locationTimeoutTimer = nullptr;
     QTimer *m_uiRefreshTimer = nullptr;
+    QTimer *m_portRefreshTimer = nullptr;
     QFile *m_uartLogFile = nullptr;
     QString m_uartLogPath;
 
@@ -125,4 +130,6 @@ private:
     DopValues m_lastDop;
     ParsedTelemetry m_pendingTelemetry;
     bool m_telemetryRefreshPending = false;
+    bool m_portsInitialized = false;
+    QStringList m_lastDetectedPorts;
 };
diff --git a/src/MapWidget.cpp b/src/MapWidget.cpp
index d4ac706..24fea30 100644
--- a/src/MapWidget.cpp
+++ b/src/MapWidget.cpp
@@ -1,9 +1,11 @@
 #include "MapWidget.h"
 
+#include <QDateTime>
 #include <QDir>
 #include <QLabel>
 #include <QLineF>
 #include <QMouseEvent>
+#include <QNativeGestureEvent>
 #include <QNetworkAccessManager>
 #include <QNetworkDiskCache>
 #include <QNetworkRequest>
@@ -13,6 +15,7 @@
 #include <QResizeEvent>
 #include <QStandardPaths>
 #include <QStringList>
+#include <QTimer>
 #include <QUrl>
 #include <QWheelEvent>
 
@@ -25,6 +28,8 @@ constexpr int TileSize = 256;
 constexpr int MinZoom = 2;
 constexpr int MaxZoom = 19;
 constexpr int MaxMemoryTileCount = 512;
+constexpr int InitialTileRetryDelayMs = 250;
+constexpr int MaximumTileRetryDelayMs = 8000;
 constexpr double Pi = 3.14159265358979323846;
 constexpr double WebMercatorRadiusMeters = 6378137.0;
 constexpr double MaxMercatorLatitude = 85.05112878;
@@ -34,6 +39,14 @@ QString tileKey(int zoom, int tileX, int tileY)
     return QStringLiteral("%1/%2/%3").arg(zoom).arg(tileX).arg(tileY);
 }
 
+QUrl tileUrl(QString urlTemplate, int zoom, int tileX, int tileY)
+{
+    urlTemplate.replace(QStringLiteral("{z}"), QString::number(zoom));
+    urlTemplate.replace(QStringLiteral("{x}"), QString::number(tileX));
+    urlTemplate.replace(QStringLiteral("{y}"), QString::number(tileY));
+    return QUrl(urlTemplate);
+}
+
 double clampLatitude(double latitude)
 {
     return std::clamp(latitude, -MaxMercatorLatitude, MaxMercatorLatitude);
@@ -52,27 +65,16 @@ double metersPerPixel(double latitude, int zoom)
     return latitudeScale * 2.0 * Pi * WebMercatorRadiusMeters / scale;
 }
 
-int preferredCurrentPointIndex(const QVector<TelemetryPoint> &points)
-{
-    constexpr qint64 CorrectedPreferenceWindowMs = 1000;
-    const int newestIndex = points.size() - 1;
-    for (int index = points.size() - 1; index >= 0; --index) {
-        if (points[index].source == LocationSource::ImuCorrected) {
-            const qint64 ageMs = points[index].receivedAt.msecsTo(
-                points[newestIndex].receivedAt);
-            return ageMs <= CorrectedPreferenceWindowMs ? index : newestIndex;
-        }
-    }
-    return newestIndex;
-}
-
 } // namespace
 
 MapWidget::MapWidget(QWidget *parent)
     : QWidget(parent)
     , m_network(new QNetworkAccessManager(this))
+    , m_tileUrlTemplate(qEnvironmentVariable(
+          "LOCATION_PLOTTER_TILE_URL_TEMPLATE",
+          QStringLiteral("https://tile.openstreetmap.org/{z}/{x}/{y}.png")))
 {
-    setMinimumSize(640, 420);
+    setMinimumSize(480, 320);
     setMouseTracking(true);
 
     const QString cacheRoot = QStandardPaths::writableLocation(QStandardPaths::CacheLocation);
@@ -104,9 +106,9 @@ void MapWidget::setPoints(const QVector<TelemetryPoint> &points)
     m_points = points;
 
     if (!m_points.isEmpty() && m_autoFollow) {
-        const TelemetryPoint &current = m_points[preferredCurrentPointIndex(m_points)];
-        m_centerLat = current.latitude;
-        m_centerLon = current.longitude;
+        const TelemetryPoint &focus = m_points[preferredFocusIndex()];
+        m_centerLat = focus.latitude;
+        m_centerLon = focus.longitude;
         if (wasEmpty) {
             m_zoom = MaxZoom;
         }
@@ -129,23 +131,55 @@ void MapWidget::fitToPoints()
     }
     double minimumLatitude = m_points.first().latitude;
     double maximumLatitude = minimumLatitude;
-    double minimumLongitude = m_points.first().longitude;
-    double maximumLongitude = minimumLongitude;
+    QVector<double> longitudes;
+    longitudes.reserve(m_points.size());
     for (const TelemetryPoint &point : m_points) {
         minimumLatitude = std::min(minimumLatitude, point.latitude);
         maximumLatitude = std::max(maximumLatitude, point.latitude);
-        minimumLongitude = std::min(minimumLongitude, point.longitude);
-        maximumLongitude = std::max(maximumLongitude, point.longitude);
+        double normalizedLongitude = std::fmod(point.longitude + 360.0, 360.0);
+        if (normalizedLongitude < 0.0) {
+            normalizedLongitude += 360.0;
+        }
+        longitudes.push_back(normalizedLongitude);
+    }
+    std::sort(longitudes.begin(), longitudes.end());
+
+    // Fit the shortest circular longitude interval. A plain min/max makes
+    // points around +180/-180 look almost a full world apart.
+    double arcStart = longitudes.first();
+    double longitudeSpan = 0.0;
+    if (longitudes.size() > 1) {
+        double largestGap = -1.0;
+        int largestGapIndex = 0;
+        for (int i = 0; i < longitudes.size(); ++i) {
+            const double current = longitudes[i];
+            const double next = i + 1 < longitudes.size()
+                ? longitudes[i + 1] : longitudes.first() + 360.0;
+            const double gap = next - current;
+            if (gap > largestGap) {
+                largestGap = gap;
+                largestGapIndex = i;
+            }
+        }
+        arcStart = largestGapIndex + 1 < longitudes.size()
+            ? longitudes[largestGapIndex + 1] : longitudes.first();
+        longitudeSpan = 360.0 - largestGap;
     }
     m_centerLat = 0.5 * (minimumLatitude + maximumLatitude);
-    m_centerLon = 0.5 * (minimumLongitude + maximumLongitude);
+    m_centerLon = std::fmod(arcStart + longitudeSpan * 0.5 + 180.0, 360.0);
+    if (m_centerLon < 0.0) {
+        m_centerLon += 360.0;
+    }
+    m_centerLon -= 180.0;
     const double availableWidth = std::max(100.0, width() * 0.82);
     const double availableHeight = std::max(100.0, height() * 0.82);
     for (int zoom = MaxZoom; zoom >= MinZoom; --zoom) {
-        const QPointF topLeft = coordinateToWorld(maximumLatitude, minimumLongitude, zoom);
-        const QPointF bottomRight = coordinateToWorld(minimumLatitude, maximumLongitude, zoom);
-        if (std::fabs(bottomRight.x() - topLeft.x()) <= availableWidth
-            && std::fabs(bottomRight.y() - topLeft.y()) <= availableHeight) {
+        const double worldWidth = static_cast<double>(TileSize) * static_cast<double>(1 << zoom);
+        const double longitudeWidth = longitudeSpan / 360.0 * worldWidth;
+        const double top = coordinateToWorld(maximumLatitude, m_centerLon, zoom).y();
+        const double bottom = coordinateToWorld(minimumLatitude, m_centerLon, zoom).y();
+        if (longitudeWidth <= availableWidth
+            && std::fabs(bottom - top) <= availableHeight) {
             m_zoom = zoom;
             break;
         }
@@ -218,9 +252,9 @@ void MapWidget::setAutoFollow(bool enabled)
 
     m_autoFollow = enabled;
     if (m_autoFollow && !m_points.isEmpty()) {
-        const TelemetryPoint &current = m_points[preferredCurrentPointIndex(m_points)];
-        m_centerLat = current.latitude;
-        m_centerLon = current.longitude;
+        const TelemetryPoint &focus = m_points[preferredFocusIndex()];
+        m_centerLat = focus.latitude;
+        m_centerLon = focus.longitude;
         update();
     }
     emit autoFollowChanged(m_autoFollow);
@@ -279,16 +313,52 @@ void MapWidget::paintEvent(QPaintEvent *)
 
 void MapWidget::wheelEvent(QWheelEvent *event)
 {
-    const int delta = event->angleDelta().y();
-    if (delta == 0) {
+    const QPoint pixelDelta = event->pixelDelta();
+    const QPoint angleDelta = event->angleDelta();
+    const double delta = !pixelDelta.isNull()
+        ? pixelDelta.y() / 36.0
+        : angleDelta.y() / 120.0;
+    if (qFuzzyIsNull(delta)) {
         return;
     }
 
     disableAutoFollowFromUserAction();
-    setZoomKeepingPoint(m_zoom + (delta > 0 ? 1 : -1), event->position());
+    m_wheelZoomAccumulator += delta;
+    while (std::abs(m_wheelZoomAccumulator) >= 1.0) {
+        const int direction = m_wheelZoomAccumulator > 0.0 ? 1 : -1;
+        setZoomKeepingPoint(m_zoom + direction, event->position());
+        m_wheelZoomAccumulator -= direction;
+    }
+    if (event->phase() == Qt::ScrollEnd) {
+        m_wheelZoomAccumulator = 0.0;
+    }
     event->accept();
 }
 
+bool MapWidget::event(QEvent *event)
+{
+    if (event->type() == QEvent::NativeGesture) {
+        auto *gesture = static_cast<QNativeGestureEvent *>(event);
+        if (gesture->gestureType() == Qt::ZoomNativeGesture) {
+            disableAutoFollowFromUserAction();
+            // macOS reports pinch magnification as small deltas. Accumulate
+            // them so map-tile zoom remains stable instead of flickering.
+            m_wheelZoomAccumulator += gesture->value() * 5.0;
+            while (std::abs(m_wheelZoomAccumulator) >= 1.0) {
+                const int direction = m_wheelZoomAccumulator > 0.0 ? 1 : -1;
+                setZoomKeepingPoint(m_zoom + direction, gesture->position());
+                m_wheelZoomAccumulator -= direction;
+            }
+            gesture->accept();
+            return true;
+        }
+        if (gesture->gestureType() == Qt::EndNativeGesture) {
+            m_wheelZoomAccumulator = 0.0;
+        }
+    }
+    return QWidget::event(event);
+}
+
 void MapWidget::mousePressEvent(QMouseEvent *event)
 {
     if (event->button() == Qt::RightButton) {
@@ -405,6 +475,15 @@ void MapWidget::drawTiles(QPainter &painter)
 
     painter.setRenderHint(QPainter::SmoothPixmapTransform, false);
 
+    struct MissingTile {
+        int x;
+        int y;
+        double distanceFromCenter;
+    };
+    QVector<MissingTile> missingTiles;
+    QSet<QString> visibleTileKeys;
+    const QPointF viewportCenter = topLeft + QPointF(width() / 2.0, height() / 2.0);
+
     for (int tileY = firstTileY; tileY <= lastTileY; ++tileY) {
         if (tileY < 0 || tileY >= tileCount) {
             continue;
@@ -413,6 +492,7 @@ void MapWidget::drawTiles(QPainter &painter)
         for (int tileX = firstTileX; tileX <= lastTileX; ++tileX) {
             const int wrappedTileX = positiveModulo(tileX, tileCount);
             const QString key = tileKey(m_zoom, wrappedTileX, tileY);
+            visibleTileKeys.insert(key);
             const QRectF target(
                 tileX * TileSize - topLeft.x(),
                 tileY * TileSize - topLeft.y(),
@@ -421,15 +501,57 @@ void MapWidget::drawTiles(QPainter &painter)
 
             const auto tileIt = m_tileCache.constFind(key);
             if (tileIt != m_tileCache.constEnd()) {
-                painter.drawPixmap(target.toRect(), *tileIt);
+                painter.drawPixmap(target, *tileIt, QRectF(tileIt->rect()));
             } else {
-                painter.fillRect(target, QColor(230, 234, 230));
-                painter.setPen(QColor(198, 205, 200));
-                painter.drawRect(target);
-                requestTile(wrappedTileX, tileY, m_zoom);
+                if (!drawCachedTileOrParent(painter, target, wrappedTileX, tileY, m_zoom)) {
+                    painter.fillRect(target, QColor(230, 234, 230));
+                    painter.setPen(QColor(198, 205, 200));
+                    painter.drawRect(target);
+                }
+                const QPointF tileCenter((tileX + 0.5) * TileSize,
+                                         (tileY + 0.5) * TileSize);
+                const QPointF offset = tileCenter - viewportCenter;
+                missingTiles.push_back({wrappedTileX, tileY,
+                                        offset.x() * offset.x() + offset.y() * offset.y()});
             }
         }
     }
+
+    // A fast pan or auto-follow jump can otherwise leave old requests ahead of
+    // the tiles that are visible now. Cancel those requests and enqueue the
+    // centre tiles first so the viewport fills in promptly.
+    cancelInvisibleTileRequests(visibleTileKeys);
+    std::sort(missingTiles.begin(), missingTiles.end(),
+              [](const MissingTile &left, const MissingTile &right) {
+                  return left.distanceFromCenter < right.distanceFromCenter;
+              });
+    for (const MissingTile &tile : missingTiles) {
+        requestTile(tile.x, tile.y, m_zoom);
+    }
+}
+
+bool MapWidget::drawCachedTileOrParent(QPainter &painter, const QRectF &target,
+                                       int tileX, int tileY, int zoom) const
+{
+    for (int parentZoom = zoom - 1; parentZoom >= MinZoom; --parentZoom) {
+        const int scale = 1 << (zoom - parentZoom);
+        const int parentX = tileX / scale;
+        const int parentY = tileY / scale;
+        const auto parentIt = m_tileCache.constFind(tileKey(parentZoom, parentX, parentY));
+        if (parentIt == m_tileCache.constEnd()) {
+            continue;
+        }
+
+        const QPixmap &parent = *parentIt;
+        const double sourceWidth = static_cast<double>(parent.width()) / scale;
+        const double sourceHeight = static_cast<double>(parent.height()) / scale;
+        const QRectF source((tileX % scale) * sourceWidth,
+                            (tileY % scale) * sourceHeight,
+                            sourceWidth, sourceHeight);
+        painter.drawPixmap(target, parent, source);
+        return true;
+    }
+    return false;
 }
 
 void MapWidget::drawTelemetry(QPainter &painter)
@@ -472,11 +594,10 @@ void MapWidget::drawTelemetry(QPainter &painter)
     drawCepMarker(painter);
 
     const bool drawNumbers = m_points.size() <= 150;
-    const int currentPointIndex = preferredCurrentPointIndex(m_points);
-    const int firstPoint = m_showRecentPoints ? 0 : currentPointIndex;
-    const int endPoint = m_showRecentPoints ? m_points.size() : currentPointIndex + 1;
-    for (int i = firstPoint; i < endPoint; ++i) {
-        const bool isLast = i == currentPointIndex;
+    const int focusIndex = preferredFocusIndex();
+    for (int i = 0; i < m_points.size(); ++i) {
+        if (!m_showRecentPoints && i != focusIndex) continue;
+        const bool isLast = i == focusIndex;
         const QPointF screen = coordinateToScreen(m_points[i].latitude, m_points[i].longitude);
         const double radius = isLast ? 8.0 : 5.0;
 
@@ -499,7 +620,7 @@ void MapWidget::drawTelemetry(QPainter &painter)
         }
     }
 
-    const TelemetryPoint &last = m_points[currentPointIndex];
+    const TelemetryPoint &last = m_points[focusIndex];
     const QPointF lastScreen = coordinateToScreen(last.latitude, last.longitude);
     QStringList lines;
     const QString latitudeText = last.latitudeText.isEmpty()
@@ -607,9 +728,10 @@ void MapWidget::drawCepMarker(QPainter &painter)
     painter.drawLine(QPointF(screen.x(), screen.y() - 11.0),
                      QPointF(screen.x(), screen.y() + 11.0));
 
-    const bool overlapsLast = !m_points.isEmpty()
-        && QLineF(screen, coordinateToScreen(m_points.last().latitude,
-                                             m_points.last().longitude)).length() < 30.0;
+    const int focusIndex = preferredFocusIndex();
+    const bool overlapsLast = focusIndex >= 0
+        && QLineF(screen, coordinateToScreen(m_points[focusIndex].latitude,
+                                             m_points[focusIndex].longitude)).length() < 30.0;
     if (!overlapsLast) {
         painter.setFont(QFont(painter.font().family(), 9, QFont::Bold));
         painter.setPen(QColor(20, 83, 78));
@@ -643,9 +765,10 @@ void MapWidget::drawAverageOverlay(QPainter &painter)
     painter.drawLine(QPointF(screen.x() - 12.0, screen.y()), QPointF(screen.x() + 12.0, screen.y()));
     painter.drawLine(QPointF(screen.x(), screen.y() - 12.0), QPointF(screen.x(), screen.y() + 12.0));
 
-    const bool overlapsLast = !m_points.isEmpty()
-        && QLineF(screen, coordinateToScreen(m_points.last().latitude,
-                                             m_points.last().longitude)).length() < 30.0;
+    const int focusIndex = preferredFocusIndex();
+    const bool overlapsLast = focusIndex >= 0
+        && QLineF(screen, coordinateToScreen(m_points[focusIndex].latitude,
+                                             m_points[focusIndex].longitude)).length() < 30.0;
     if (!overlapsLast) {
         painter.setFont(QFont(painter.font().family(), 9, QFont::Bold));
         const QRectF labelRect(screen + QPointF(12.0, 8.0), QSizeF(72.0, 20.0));
@@ -670,20 +793,27 @@ void MapWidget::requestTile(int tileX, int tileY, int zoom)
         return;
     }
 
+    const qint64 now = QDateTime::currentMSecsSinceEpoch();
+    if (m_tileRetryAfterMs.value(key, 0) > now) {
+        return;
+    }
+
     m_pendingTiles.insert(key);
-    const QUrl url(QStringLiteral("https://tile.openstreetmap.org/%1/%2/%3.png")
-                       .arg(zoom)
-                       .arg(tileX)
-                       .arg(tileY));
-    QNetworkRequest request(url);
-    request.setRawHeader("User-Agent", "RocketLocationPlotter/0.2 (Qt desktop application)");
+    QNetworkRequest request(tileUrl(m_tileUrlTemplate, zoom, tileX, tileY));
+    request.setRawHeader("User-Agent", "RocketLocationPlotter/0.3 (Qt desktop application)");
+    request.setTransferTimeout(15000);
     QNetworkReply *reply = m_network->get(request);
     reply->setProperty("tileKey", key);
+    m_tileReplies.insert(key, reply);
 
     connect(reply, &QNetworkReply::finished, this, [this, reply]() {
         const QString key = reply->property("tileKey").toString();
         m_pendingTiles.remove(key);
+        if (m_tileReplies.value(key) == reply) {
+            m_tileReplies.remove(key);
+        }
 
+        bool loaded = false;
         if (reply->error() == QNetworkReply::NoError) {
             QPixmap pixmap;
             if (pixmap.loadFromData(reply->readAll())) {
@@ -691,14 +821,77 @@ void MapWidget::requestTile(int tileX, int tileY, int zoom)
                     m_tileCache.erase(m_tileCache.begin());
                 }
                 m_tileCache.insert(key, pixmap);
-                update();
+                m_tileFailureCounts.remove(key);
+                m_tileRetryAfterMs.remove(key);
+                loaded = true;
             }
         }
 
+        const bool cancelled = reply->property("tileCancelled").toBool();
+        if (!loaded && !cancelled) {
+            const int failures = m_tileFailureCounts.value(key, 0) + 1;
+            m_tileFailureCounts.insert(key, failures);
+            const int shift = std::min(failures - 1, 5);
+            const int retryDelay = std::min(MaximumTileRetryDelayMs,
+                                            InitialTileRetryDelayMs * (1 << shift));
+            m_tileRetryAfterMs.insert(key,
+                QDateTime::currentMSecsSinceEpoch() + retryDelay);
+            QTimer::singleShot(retryDelay, this, [this, key]() {
+                repaintWhenTileRetryIsReady(key);
+            });
+        }
+
+        if (loaded) {
+            update();
+        }
+
         reply->deleteLater();
     });
 }
 
+void MapWidget::cancelInvisibleTileRequests(const QSet<QString> &visibleTileKeys)
+{
+    QVector<QNetworkReply *> obsoleteReplies;
+    for (auto it = m_tileReplies.cbegin(); it != m_tileReplies.cend(); ++it) {
+        if (!visibleTileKeys.contains(it.key())) {
+            obsoleteReplies.push_back(it.value());
+        }
+    }
+
+    for (QNetworkReply *reply : obsoleteReplies) {
+        if (reply == nullptr || reply->isFinished()) {
+            continue;
+        }
+        reply->setProperty("tileCancelled", true);
+        reply->abort();
+    }
+
+    for (auto it = m_tileRetryAfterMs.begin(); it != m_tileRetryAfterMs.end();) {
+        if (visibleTileKeys.contains(it.key())) {
+            ++it;
+            continue;
+        }
+        m_tileFailureCounts.remove(it.key());
+        it = m_tileRetryAfterMs.erase(it);
+    }
+}
+
+void MapWidget::repaintWhenTileRetryIsReady(const QString &key)
+{
+    if (!m_tileRetryAfterMs.contains(key)) {
+        return;
+    }
+    const qint64 remaining = m_tileRetryAfterMs.value(key, 0)
+        - QDateTime::currentMSecsSinceEpoch();
+    if (remaining > 0) {
+        QTimer::singleShot(static_cast<int>(remaining), this, [this, key]() {
+            repaintWhenTileRetryIsReady(key);
+        });
+        return;
+    }
+    update();
+}
+
 void MapWidget::setZoomKeepingPoint(int newZoom, const QPointF &screenAnchor)
 {
     newZoom = std::clamp(newZoom, MinZoom, MaxZoom);
@@ -725,3 +918,17 @@ void MapWidget::disableAutoFollowFromUserAction()
     m_autoFollow = false;
     emit autoFollowChanged(false);
 }
+
+int MapWidget::preferredFocusIndex() const
+{
+    constexpr qint64 CorrectedPreferenceWindowMs = 1000;
+    const int newestIndex = m_points.size() - 1;
+    for (int index = m_points.size() - 1; index >= 0; --index) {
+        if (m_points[index].source == LocationSource::ImuCorrected) {
+            const qint64 ageMs = m_points[index].receivedAt.msecsTo(
+                m_points[newestIndex].receivedAt);
+            return ageMs <= CorrectedPreferenceWindowMs ? index : newestIndex;
+        }
+    }
+    return newestIndex;
+}
diff --git a/src/MapWidget.h b/src/MapWidget.h
index 5e67a52..b40d5fd 100644
--- a/src/MapWidget.h
+++ b/src/MapWidget.h
@@ -11,6 +11,7 @@
 #include <optional>
 
 class QNetworkAccessManager;
+class QNetworkReply;
 class QLabel;
 
 class MapWidget : public QWidget {
@@ -42,6 +43,7 @@ signals:
     void referenceLocationSelected(double latitude, double longitude);
 
 protected:
+    bool event(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
     void wheelEvent(QWheelEvent *event) override;
     void mousePressEvent(QMouseEvent *event) override;
@@ -63,15 +65,24 @@ private:
     void drawCepOverlay(QPainter &painter);
     void drawCepMarker(QPainter &painter);
     void drawEmptyState(QPainter &painter);
+    bool drawCachedTileOrParent(QPainter &painter, const QRectF &target,
+                                int tileX, int tileY, int zoom) const;
     void requestTile(int tileX, int tileY, int zoom);
+    void cancelInvisibleTileRequests(const QSet<QString> &visibleTileKeys);
+    void repaintWhenTileRetryIsReady(const QString &key);
     void setZoomKeepingPoint(int newZoom, const QPointF &screenAnchor);
     void disableAutoFollowFromUserAction();
+    int preferredFocusIndex() const;
 
     QVector<TelemetryPoint> m_points;
     QNetworkAccessManager *m_network = nullptr;
     QLabel *m_attributionLabel = nullptr;
     QHash<QString, QPixmap> m_tileCache;
     QSet<QString> m_pendingTiles;
+    QHash<QString, QNetworkReply *> m_tileReplies;
+    QHash<QString, int> m_tileFailureCounts;
+    QHash<QString, qint64> m_tileRetryAfterMs;
+    QString m_tileUrlTemplate;
 
     double m_centerLat = 39.0;
     double m_centerLon = 35.0;
@@ -90,4 +101,5 @@ private:
     std::optional<double> m_cepRadiusMeters;
     bool m_dragging = false;
     QPoint m_lastMousePos;
+    double m_wheelZoomAccumulator = 0.0;
 };
diff --git a/src/RinexNavigation.cpp b/src/RinexNavigation.cpp
index c839d5a..fcf862c 100644
--- a/src/RinexNavigation.cpp
+++ b/src/RinexNavigation.cpp
@@ -6,6 +6,7 @@
 #include <QNetworkReply>
 #include <QNetworkRequest>
 #include <QStandardPaths>
+#include <QTimeZone>
 #include <QUrl>
 
 #include <zlib.h>
@@ -148,7 +149,9 @@ void RinexNavigation::handleDownload(const QByteArray &compressed, const QDate &
             return;
         }
         setLoading(false);
-        emit statusChanged(QStringLiteral("RINEX okunamadi: %1").arg(error), true);
+        if (!loadCache()) {
+            emit statusChanged(QStringLiteral("RINEX okunamadi: %1").arg(error), true);
+        }
         return;
     }
 
@@ -180,7 +183,7 @@ bool RinexNavigation::loadCache()
     emit statusChanged(QStringLiteral("%1 GPS uydusu · onbellekteki RINEX · %2")
                            .arg(positions.size())
                            .arg(now.toLocalTime().toString(
-                               QStringLiteral("HH:mm:ss t"))), true);
+                               QStringLiteral("HH:mm:ss t"))), false);
     return true;
 }
 
diff --git a/tests/main_window_tests.cpp b/tests/main_window_tests.cpp
index 908444f..8192967 100644
--- a/tests/main_window_tests.cpp
+++ b/tests/main_window_tests.cpp
@@ -3,6 +3,7 @@
 #include "../src/MapWidget.h"
 
 #include <QApplication>
+#include <QAction>
 #include <QCheckBox>
 #include <QComboBox>
 #include <QDoubleSpinBox>
@@ -21,6 +22,7 @@
 #include <QTemporaryDir>
 
 #include <cassert>
+#include <cmath>
 
 namespace {
 
@@ -88,6 +90,10 @@ int main(int argc, char **argv)
     auto *map = window.findChild<MapWidget *>();
     auto *mainViewTabs = window.findChild<QTabWidget *>(QStringLiteral("mainViewTabs"));
     auto *sideSplitter = window.findChild<QSplitter *>(QStringLiteral("sideSplitter"));
+    auto *rinexUpdateButton = window.findChild<QPushButton *>(QStringLiteral("rinexUpdateButton"));
+    auto *openLogAction = window.findChild<QAction *>(QStringLiteral("openLogAction"));
+    auto *toggleSerialAction = window.findChild<QAction *>(QStringLiteral("toggleSerialAction"));
+    auto *rinexUpdateAction = window.findChild<QAction *>(QStringLiteral("rinexUpdateAction"));
     assert(table != nullptr);
     assert(referenceLatInput != nullptr);
     assert(referenceLonInput != nullptr);
@@ -118,6 +124,32 @@ int main(int argc, char **argv)
     assert(mainViewTabs->count() == 2);
     assert(sideSplitter != nullptr);
     assert(sideSplitter->orientation() == Qt::Vertical);
+    assert(rinexUpdateButton != nullptr);
+    assert(!rinexUpdateButton->toolTip().isEmpty());
+    assert(openLogAction != nullptr && !openLogAction->shortcut().isEmpty());
+    assert(toggleSerialAction != nullptr && !toggleSerialAction->shortcut().isEmpty());
+    assert(rinexUpdateAction != nullptr && !rinexUpdateAction->shortcut().isEmpty());
+
+    QVector<TelemetryPoint> followPoints;
+    TelemetryPoint gpsPoint;
+    gpsPoint.source = LocationSource::Gps;
+    gpsPoint.latitude = 40.0;
+    gpsPoint.longitude = 29.0;
+    followPoints.push_back(gpsPoint);
+    TelemetryPoint correctedPoint = gpsPoint;
+    correctedPoint.source = LocationSource::ImuCorrected;
+    correctedPoint.latitude = 40.25;
+    correctedPoint.longitude = 29.5;
+    followPoints.push_back(correctedPoint);
+    TelemetryPoint trajectoryPoint = gpsPoint;
+    trajectoryPoint.source = LocationSource::Trajectory;
+    trajectoryPoint.latitude = 41.0;
+    trajectoryPoint.longitude = 30.0;
+    followPoints.push_back(trajectoryPoint);
+    map->setPoints(followPoints);
+    assert(std::abs(map->centerCoordinate().x() - 40.25) < 0.000001);
+    assert(std::abs(map->centerCoordinate().y() - 29.5) < 0.000001);
+    map->clearPoints();
 
     sendLine(window, QStringLiteral("[TRK] tracked satellites=2 prn_indices=[2,7]"));
     assert(map != nullptr);
@@ -185,6 +217,24 @@ int main(int argc, char **argv)
     assert(table->model()->data(table->model()->index(0, 1)).toString()
            == QStringLiteral("Trajectory (truth)"));
 
+    QTemporaryFile splitReplayLog;
+    assert(splitReplayLog.open());
+    splitReplayLog.write("latitude: 40.25\nlongitude: 29.50\n");
+    splitReplayLog.flush();
+    assert(window.loadTelemetryLog(splitReplayLog.fileName()));
+    assert(table->model()->rowCount() == 1);
+
+    // A partial fix from an earlier solve must not be completed using a field
+    // from the following solve.
+    assert(QMetaObject::invokeMethod(&window, "clearPoints", Qt::DirectConnection));
+    sendLine(window, QStringLiteral("NAV solve start"));
+    sendLine(window, QStringLiteral("latitude: 40.0"));
+    sendLine(window, QStringLiteral("NAV solve start"));
+    sendLine(window, QStringLiteral("longitude: 29.0"));
+    sendLine(window, QStringLiteral("NAV solve done"));
+    flushUpdates(window);
+    assert(table->model()->rowCount() == 0);
+
     assert(QMetaObject::invokeMethod(&window, "clearPoints", Qt::DirectConnection));
     sendLine(window, QStringLiteral(
         "lat=40.78925034214206846173 long=29.46277530841727809729"));
diff --git a/tests/map_widget_tests.cpp b/tests/map_widget_tests.cpp
new file mode 100644
index 0000000..11f67ff
--- /dev/null
+++ b/tests/map_widget_tests.cpp
@@ -0,0 +1,73 @@
+#include "../src/MapWidget.h"
+
+#include <QApplication>
+#include <QElapsedTimer>
+#include <QHostAddress>
+#include <QSet>
+#include <QTcpServer>
+#include <QTcpSocket>
+#include <QThread>
+
+#include <cassert>
+
+int main(int argc, char **argv)
+{
+    QApplication app(argc, argv);
+
+    QTcpServer tileServer;
+    assert(tileServer.listen(QHostAddress::LocalHost, 0));
+
+    int requestCount = 0;
+    QSet<QByteArray> requestedPaths;
+    QObject::connect(&tileServer, &QTcpServer::newConnection, [&]() {
+        while (tileServer.hasPendingConnections()) {
+            QTcpSocket *socket = tileServer.nextPendingConnection();
+            const auto respond = [&, socket]() {
+                if (!socket->canReadLine()) {
+                    return;
+                }
+                const QByteArray requestLine = socket->readLine().trimmed();
+                const QList<QByteArray> fields = requestLine.split(' ');
+                if (fields.size() >= 2) {
+                    ++requestCount;
+                    requestedPaths.insert(fields[1]);
+                }
+                socket->readAll();
+                socket->write("HTTP/1.1 503 Service Unavailable\r\n"
+                              "Content-Length: 0\r\n"
+                              "Connection: close\r\n\r\n");
+                socket->disconnectFromHost();
+            };
+            QObject::connect(socket, &QTcpSocket::readyRead, socket, respond);
+            QObject::connect(socket, &QTcpSocket::disconnected,
+                             socket, &QObject::deleteLater);
+            respond();
+        }
+    });
+
+    const QByteArray tileUrl = QByteArray("http://127.0.0.1:")
+        + QByteArray::number(tileServer.serverPort()) + "/{z}/{x}/{y}.png";
+    qputenv("LOCATION_PLOTTER_TILE_URL_TEMPLATE", tileUrl);
+
+    {
+        MapWidget map;
+        map.resize(640, 480);
+        map.show();
+
+        QElapsedTimer timer;
+        timer.start();
+        while (timer.elapsed() < 1200) {
+            app.processEvents(QEventLoop::AllEvents, 50);
+            QThread::msleep(5);
+        }
+
+        // Every URL fails. Seeing any URL more than once proves that a failed
+        // tile schedules a new paint/request instead of remaining a blank
+        // placeholder forever.
+        assert(!requestedPaths.isEmpty());
+        assert(requestCount > requestedPaths.size());
+    }
+
+    qunsetenv("LOCATION_PLOTTER_TILE_URL_TEMPLATE");
+    return 0;
+}