Moved NTRIP classes to NmeaParser lib and introduced new GnssMonitor class for simplified monitoring of GNSS messages

src/NmeaParser/Gnss/GnssMonitor.cs

@@ -0,0 +1,305 @@
+//  *******************************************************************************
+//  *  Licensed under the Apache License, Version 2.0 (the "License");
+//  *  you may not use this file except in compliance with the License.
+//  *  You may obtain a copy of the License at
+//  *
+//  *  http://www.apache.org/licenses/LICENSE-2.0
+//  *
+//  *   Unless required by applicable law or agreed to in writing, software
+//  *   distributed under the License is distributed on an "AS IS" BASIS,
+//  *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  *   See the License for the specific language governing permissions and
+//  *   limitations under the License.
+//  ******************************************************************************
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using NmeaParser.Messages;
+
+namespace NmeaParser.Gnss
+{
+    /// <summary>
+    /// Helper class for monitoring GNSS messages and combine them into a single useful location info
+    /// </summary>
+    public class GnssMonitor
+    {
+        private bool m_supportGNMessages; // If device detect GN* messages, ignore all other Talker ID
+        private bool m_supportGGaMessages; //If device support GGA, ignore RMC for location
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GnssMonitor"/> class.
+        /// </summary>
+        /// <param name="device">The NMEA device to monitor for GNSS messages</param>
+        public GnssMonitor(NmeaDevice device)
+        {
+            if (device == null)
+                throw new ArgumentNullException(nameof(device));
+            Device = device;
+            Device.MessageReceived += NmeaMessageReceived;
+        }
+
+        /// <summary>
+        /// Gets the NMEA device that is being monitored
+        /// </summary>
+        public NmeaDevice Device { get; }
+
+        private void NmeaMessageReceived(object sender, NmeaParser.NmeaMessageReceivedEventArgs e)
+        {
+            OnMessageReceived(e.Message);
+        }
+
+        /// <summary>
+        /// Called when a message is received.
+        /// </summary>
+        /// <param name="message">The NMEA message that was received</param>
+        protected virtual void OnMessageReceived(NmeaMessage message) 
+        { 
+            bool isNewFix = false;
+            bool lostFix = false;
+            double lat = 0;
+            double lon = 0;
+            AllMessages[message.MessageType] = message;
+            
+            if (message.TalkerId == NmeaParser.Talker.GlobalNavigationSatelliteSystem)
+                m_supportGNMessages = true; // Support for GN* messages detected
+            else if (m_supportGNMessages && message.TalkerId != NmeaParser.Talker.GlobalNavigationSatelliteSystem)
+                return; // If device supports combined GN* messages, ignore non-GN messages
+            if (message is ITimestampedMessage ts)
+                FixTime = ts.Timestamp;
+
+            if (message is NmeaParser.Messages.Garmin.Pgrme rme)
+            {
+                HorizontalError = rme.HorizontalError;
+                VerticalError = rme.VerticalError;
+            }
+            else if (message is Gst gst)
+            {
+                Gst = gst;
+                VerticalError = gst.SigmaHeightError;
+                HorizontalError = Math.Round(Math.Sqrt(Gst.SigmaLatitudeError * Gst.SigmaLatitudeError + Gst.SigmaLongitudeError * Gst.SigmaLongitudeError), 3);
+            }
+            else if (message is Rmc rmc)
+            {
+                Rmc = rmc;
+                if (!m_supportGGaMessages)
+                {
+                    if (Rmc.Active)
+                    {
+                        lat = Rmc.Latitude;
+                        lon = Rmc.Longitude;
+                        isNewFix = true;
+                    }
+                    else
+                    {
+                        lostFix = true;
+                    }
+                }
+            }
+            else if (message is Dtm dtm)
+            {
+                if (Dtm?.Checksum != dtm.Checksum)
+                {
+                    // Datum change
+                    Dtm = dtm;
+                    Latitude = double.NaN;
+                    Longitude = double.NaN;
+                    IsFixValid = false;
+                }
+            }
+            else if (message is Gga gga)
+            {
+                Gga = gga;
+                m_supportGGaMessages = true;
+                if (gga.Quality != Gga.FixQuality.Invalid)
+                {
+                    lat = gga.Latitude;
+                    lon = gga.Longitude;
+                    GeoidHeight = gga.GeoidalSeparation;
+                    Altitude = gga.Altitude + gga.GeoidalSeparation; //Convert to ellipsoidal height
+                }
+                if (gga.Quality == Gga.FixQuality.Invalid || gga.Quality == Gga.FixQuality.Estimated)
+                {
+                    lostFix = true;
+                }
+                isNewFix = true;
+            }
+            else if (message is Gsa gsa)
+            {
+                Gsa = gsa;
+            }
+            else if (message is Vtg vtg)
+            {
+                Vtg = vtg;
+            }
+            if (lostFix)
+            {
+                if (!IsFixValid)
+                {
+                    IsFixValid = false;
+                    LocationLost?.Invoke(this, EventArgs.Empty);
+                }
+            }
+            if (isNewFix)
+            {
+                Latitude = lat;
+                Longitude = lon;
+                IsFixValid = true;
+                LocationChanged?.Invoke(this, EventArgs.Empty);
+            }
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether the current fix is valid.
+        /// </summary>
+        /// <remarks>
+        /// If <c>false</c> the provided values like <see cref="Latitude"/> and <see cref="Longitude"/> are no longer current and reflect the last known location.
+        /// </remarks>
+        /// <seealso cref="LocationLost"/>
+        public bool IsFixValid { get; private set; }
+        
+        /// <summary>
+        /// Gets the latitude for the current or last known location.
+        /// </summary>
+        /// <seealso cref="IsFixValid"/>
+        /// <seealso cref="Longitude"/>
+        public double Latitude { get; private set; } = double.NaN;
+
+        /// <summary>
+        /// Gets the longitude for the current or last known location.
+        /// </summary>
+        /// <seealso cref="IsFixValid"/>
+        /// <seealso cref="Latitude"/>
+        public double Longitude { get; private set; } = double.NaN;
+        
+        /// <summary>
+        /// Gets the geight above the ellipsoid
+        /// </summary>
+        public double Altitude { get; private set; } = double.NaN;
+        /// <summary>
+        /// Gets the Geoid Height. Add this value to <see cref="Altitude"/> to get the Geoid heights which is roughly MSL heights.
+        /// </summary>
+        public double GeoidHeight { get; private set; } = double.NaN;
+
+        /// <summary>
+        /// Gets the speed in knots
+        /// </summary>
+        public double Speed => Rmc?.Speed ?? Vtg?.SpeedKnots ?? double.NaN;
+
+        /// <summary>
+        /// Gets the current cource
+        /// </summary>
+        public double Course => Rmc?.Course ?? double.NaN;
+
+        /// <summary>
+        /// Gets an estimate of the horizontal error in meters
+        /// </summary>
+        public double HorizontalError { get; private set; } = double.NaN;
+
+        /// <summary>
+        /// Gets an estimate of the vertical error in meters
+        /// </summary>
+        public double VerticalError { get; private set; } = double.NaN;
+
+        /// <summary>
+        /// Gets the horizontal dilution of precision
+        /// </summary>
+        public double Hdop => Gsa?.Hdop ?? Gga?.Hdop ?? double.NaN;
+
+        /// <summary>
+        /// Gets the 3D point dilution of precision
+        /// </summary>
+        public double Pdop => Gsa?.Pdop ?? double.NaN;
+
+        /// <summary>
+        /// Gets the vertical dilution of precision
+        /// </summary>
+        public double Vdop => Gsa?.Vdop ?? double.NaN;
+
+        /// <summary>
+        /// Gets the latest known GSA message.
+        /// </summary>
+        public Gsa? Gsa { get; private set; }
+
+        /// <summary>
+        /// Gets the latest known GGA message.
+        /// </summary>
+        public Gga? Gga { get; private set; }
+
+        /// <summary>
+        /// Gets the latest known RMC message.
+        /// </summary>
+        public Rmc? Rmc { get; private set; }
+
+        /// <summary>
+        /// Gets the latest known GST message.
+        /// </summary>
+        public Gst? Gst { get; private set; }
+
+        /// <summary>
+        /// Gets the latest known DTM message.
+        /// </summary>
+        public Dtm? Dtm { get; private set; }
+
+        /// <summary>
+        /// Gets the latest known VTG message.
+        /// </summary>
+        public Vtg? Vtg { get; private set; }
+
+        /// <summary>
+        /// Gets the current fix time
+        /// </summary>
+        public TimeSpan FixTime { get; private set; }
+
+        /// <summary>
+        /// Gets a list of satellite vehicles in the sky
+        /// </summary>
+        public IEnumerable<SatelliteVehicle> Satellites => AllMessages.Values.OfType<Gsv>().SelectMany(s => s.SVs);
+
+        /// <summary>
+        /// Gets the number of satellites in the sky
+        /// </summary>
+        public int SatellitesInView => AllMessages.Values.OfType<Gsv>().Sum(s => s.SatellitesInView);
+
+        /// <summary>
+        /// Gets the quality of the current fix
+        /// </summary>
+        public Gga.FixQuality FixQuality => !IsFixValid ? Gga.FixQuality.Invalid : (Gga?.Quality ?? Gga.FixQuality.GpsFix);
+
+        /// <summary>
+        /// Gets a list of all NMEA messages currently part of this location
+        /// </summary>
+        public Dictionary<string, NmeaMessage> AllMessages { get; } = new Dictionary<string, NmeaMessage>();
+
+        /// <summary>
+        /// Gets a value indicating the current Datum being used.
+        /// </summary>
+        public string Datum
+        {
+            get
+            {
+                if (Dtm == null)
+                    return "WGS84";
+                switch (Dtm.ReferenceDatumCode)
+                {
+                    case "W84": return "WGS84";
+                    case "W72": return "WGS72";
+                    case "S85": return "SGS85";
+                    case "P90": return "PE90";
+                    default: return Dtm.ReferenceDatumCode;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Raised when a new location has been updated
+        /// </summary>
+        public event EventHandler? LocationChanged;
+
+        /// <summary>
+        /// Raised if location tracking was lost
+        /// </summary>
+        /// <seealso cref="IsFixValid"/>
+        public event EventHandler? LocationLost;
+    }
+}

src/NmeaParser/Gnss/Ntrip/Carrier.cs

@@ -14,10 +14,24 @@
 
 namespace NmeaParser.Gnss.Ntrip
 {
+    /// <summary>
+    /// Enumeration for the carrier used by the <see cref="NtripStream"/>
+    /// </summary>
     public enum Carrier : int
     {
-        No = 0,
+        /// <summary>
+        /// None / unknown
+        /// </summary>
+        None = 0,
+
+        /// <summary>
+        /// L1 wave
+        /// </summary>
         L1 = 1,
+
+        /// <summary>
+        /// L1 and L2 waves
+        /// </summary>
         L1L2 = 2
     }
 }

src/NmeaParser/Gnss/Ntrip/Caster.cs

@@ -17,6 +17,9 @@ using System.Net;
 
 namespace NmeaParser.Gnss.Ntrip
 {
+    /// <summary>
+    /// Gets metadata about the NTRIP Caster
+    /// </summary>
     public class Caster : NtripSource
     {
         internal Caster (string[] d)
@@ -33,6 +36,18 @@ namespace NmeaParser.Gnss.Ntrip
             FallbackAddress = IPAddress.Parse(d[9]);
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Caster"/> class.
+        /// </summary>
+        /// <param name="address"></param>
+        /// <param name="port"></param>
+        /// <param name="identifier"></param>
+        /// <param name="_operator"></param>
+        /// <param name="supportsNmea"></param>
+        /// <param name="countryCode"></param>
+        /// <param name="latitude"></param>
+        /// <param name="longitude"></param>
+        /// <param name="fallbackkAddress"></param>
         public Caster(IPAddress address, int port, string identifier, string _operator, bool supportsNmea, string countryCode, double latitude, double longitude, IPAddress fallbackkAddress)
         {
             Address = address;
@@ -46,14 +61,49 @@ namespace NmeaParser.Gnss.Ntrip
             FallbackAddress = fallbackkAddress;
         }
 
+        /// <summary>
+        /// Gets the caster IP Address
+        /// </summary>
         public IPAddress Address { get; }
+
+        /// <summary>
+        /// Gets the caster port
+        /// </summary>
         public int Port { get; }
+
+        /// <summary>
+        /// Gets the caster identifier
+        /// </summary>
         public string Identifier { get; }
+
+        /// <summary>
+        /// Gets the caster operator
+        /// </summary>
         public string Operator { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether it supports NMEA
+        /// </summary>
         public bool SupportsNmea { get; }
+
+        /// <summary>
+        /// Gets the country code for the caster origin
+        /// </summary>
         public string CountryCode { get; }
+
+        /// <summary>
+        /// Gets the latitude for the caster
+        /// </summary>
         public double Latitude { get; }
+        
+        /// <summary>
+        /// Gets the longitude for the caster
+        /// </summary>
         public double Longitude { get; }
+
+        /// <summary>
+        /// Gets the fallback address for the caster
+        /// </summary>
         public IPAddress FallbackAddress { get; }
     }
 }

src/NmeaParser/Gnss/Ntrip/Client.cs

@@ -11,7 +11,6 @@
 //  *   See the License for the specific language governing permissions and
 //  *   limitations under the License.
 //  ******************************************************************************
-#nullable enable
 
 using System;
 using System.Collections.Generic;
@@ -21,6 +20,9 @@ using System.Threading.Tasks;
 
 namespace NmeaParser.Gnss.Ntrip
 {
+    /// <summary>
+    /// NTRIP Client for querying an NTRIP server and opening an NTRIP stream
+    /// </summary>
     public class Client : IDisposable
     {
         private readonly string _host;
@@ -30,17 +32,33 @@ namespace NmeaParser.Gnss.Ntrip
         private bool connected;
         private Task? runningTask;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Client"/> class
+        /// </summary>
+        /// <param name="host">Host name</param>
+        /// <param name="port">Port, usually 2101</param>
         public Client(string host, int port)
         {
             _host = host;
             _port = port;
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Client"/> class
+        /// </summary>
+        /// <param name="host">Host name</param>
+        /// <param name="port">Port, usually 2101</param>
+        /// <param name="username">Username</param>
+        /// <param name="password">Password</param>
         public Client(string host, int port, string username, string password) : this(host, port)
         {
             _auth = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(username + ":" + password));
         }
 
+        /// <summary>
+        /// Gets a list of sources from the NTRIP endpoint
+        /// </summary>
+        /// <returns></returns>
         public IEnumerable<NtripSource> GetSourceTable()
         {
             string data = "";
@@ -77,8 +95,8 @@ namespace NmeaParser.Gnss.Ntrip
         {
             var sckt = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
             sckt.Blocking = true;
+            sckt.ReceiveTimeout = 5000;
             sckt.Connect(_host, _port);
-
             string msg = $"GET /{path} HTTP/1.1\r\n";
             msg += "User-Agent: NTRIP ntripclient\r\n";
             if (_auth != null)
@@ -92,11 +110,29 @@ namespace NmeaParser.Gnss.Ntrip
             sckt.Send(data);
             return sckt;
         }
-
+        /// <summary>
-        public void Connect(string strName)
+        /// Connects to the endpoint for the specified <see cref="NtripStream.Mountpoint"/>
+        /// </summary>
+        /// <param name="stream"></param>
+        public void Connect(NtripStream stream)
         {
+            if (stream == null)
+                throw new ArgumentNullException(nameof(stream));
+            Connect(stream.Mountpoint);
+        }
+
+        /// <summary>
+        /// Connects to the endpoint for the specified <see cref="NtripStream.Mountpoint"/>
+        /// </summary>
+        /// <param name="mountPoint"></param>
+        public void Connect(string mountPoint)
+        {
+            if (mountPoint == null)
+                throw new ArgumentNullException(nameof(mountPoint));
+            if (string.IsNullOrWhiteSpace(mountPoint))
+                throw new ArgumentException(nameof(mountPoint));
             if (sckt != null) throw new Exception("Connection already open");
-            sckt = Request(strName);
+            sckt = Request(mountPoint);
             connected = true;
             runningTask = Task.Run(ReceiveThread);
         }
@@ -104,10 +140,10 @@ namespace NmeaParser.Gnss.Ntrip
         private async Task ReceiveThread()
         {
             byte[] buffer = new byte[65536];
-            sckt.ReceiveTimeout = 1000;
+            
             while (connected && sckt != null)
             {
-                int count = sckt.Receive(buffer, SocketFlags.None, out SocketError errorCode);
+                int count = sckt.Receive(buffer);
                 if (count > 0)
                 {
                     DataReceived?.Invoke(this, buffer.Take(count).ToArray());
@@ -128,6 +164,10 @@ namespace NmeaParser.Gnss.Ntrip
             sckt = null;
         }
 
+        /// <summary>
+        /// Shuts down the stream
+        /// </summary>
+        /// <returns></returns>
         public Task CloseAsync()
         {
             if (runningTask != null)
@@ -137,15 +177,30 @@ namespace NmeaParser.Gnss.Ntrip
                 runningTask = null;
                 return t;
             }
+#if NETSTANDARD || NETFX
+            return Task.FromResult<object?>(null);
+#else
             return Task.CompletedTask;
+#endif
         }
 
+        /// <inheritdoc />
         public void Dispose()
         {
             _ = CloseAsync();
         }
 
+        /// <summary>
+        /// Fired when bytes has been received from the stream
+        /// </summary>
         public event EventHandler<byte[]>? DataReceived;
-        public event EventHandler Disconnected;
+
+        /// <summary>
+        /// Fired if the socket connection was dropped, and the connection was closed.
+        /// </summary>
+        /// <remarks>
+        /// This event is useful for handling network glitches, and trying to retry connection by calling <see cref="Connect(string)"/> again a few times.
+        /// </remarks>
+        public event EventHandler? Disconnected;
     }
 }

src/NmeaParser/Gnss/Ntrip/NtripSource.cs

@@ -14,8 +14,14 @@
 
 namespace NmeaParser.Gnss.Ntrip
 {
-    public class NtripSource
+    /// <summary>
+    /// Baseclass for the sources returned from an NTRIP Service
+    /// </summary>
+    public abstract class NtripSource
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NtripSource"/> class.
+        /// </summary>
         protected NtripSource()
         {
         }

src/NmeaParser/Gnss/Ntrip/NtripStream.cs

@@ -17,6 +17,9 @@ using System.Globalization;
 
 namespace NmeaParser.Gnss.Ntrip
 {
+    /// <summary>
+    /// Metadata on an NTRIP Data Stream
+    /// </summary>
     public class NtripStream : NtripSource
     {
         internal NtripStream(string[] d)
@@ -38,15 +41,54 @@ namespace NmeaParser.Gnss.Ntrip
             SupportsNmea = d[11] == "1";
         }
 
+        /// <summary>
+        /// The mountpoint used with <see cref="Client.Connect(string)"/>
+        /// </summary>
         public string Mountpoint { get; }
+        
+        /// <summary>
+        /// Gets the unique identifier for the stream
+        /// </summary>
         public string Identifier { get; }
+
+        /// <summary>
+        /// Gets the stream format
+        /// </summary>
         public string Format { get; }
+
+        /// <summary>
+        /// Gets the details about the format
+        /// </summary>
         public string FormatDetails { get; }
+
+        /// <summary>
+        /// Gets the wave carrier for the stream
+        /// </summary>
         public Carrier Carrier { get; }
+        
+        /// <summary>
+        /// Gets the network for the stream
+        /// </summary>
         public string Network { get; }
+        
+        /// <summary>
+        /// Gets the country code for where the stream originates
+        /// </summary>
         public string CountryCode { get; }
+        
+        /// <summary>
+        /// Gets the latitude location of the base station
+        /// </summary>
         public double Latitude { get; }
+
+        /// <summary>
+        /// Gets the longitude location of the base station
+        /// </summary>
         public double Longitude { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether the stream supports NMEA
+        /// </summary>
         public bool SupportsNmea { get; }
     }
 }

src/SampleApp.WinDesktop/GnssMonitorView.xaml

@@ -0,0 +1,28 @@
+<UserControl x:Class="SampleApp.WinDesktop.GnssMonitorView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+			 xmlns:local="clr-namespace:SampleApp.WinDesktop"
+             mc:Ignorable="d" 
+             d:DesignHeight="300" d:DesignWidth="300">
+	<StackPanel DataContext="{Binding RelativeSource={RelativeSource AncestorType=UserControl}, Path=Message}">
+		<Border Background="LightGray" Padding="10" Margin="-10,-10,-10,5" x:Name="HeaderPanel">
+            <TextBlock Text="{Binding MessageType}" x:Name="typeName" FontSize="20" FontWeight="Bold" Foreground="White" />
+        </Border>
+        <ItemsControl x:Name="Values">
+            <ItemsControl.ItemTemplate>
+                <DataTemplate>
+                    <Grid >
+                        <Grid.ColumnDefinitions>
+                            <ColumnDefinition MinWidth="100" Width="Auto" />
+                            <ColumnDefinition Width="*" />
+                        </Grid.ColumnDefinitions>
+                        <TextBlock Text="{Binding Key}" Margin="0,0,5,0" VerticalAlignment="Top" />
+                        <TextBlock Text="{Binding Value}" TextWrapping="Wrap" Grid.Column="1" VerticalAlignment="Top" />
+                    </Grid>
+                </DataTemplate>
+            </ItemsControl.ItemTemplate>
+        </ItemsControl>
+    </StackPanel>
+</UserControl>

src/SampleApp.WinDesktop/GnssMonitorView.xaml.cs

@@ -0,0 +1,76 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using NmeaParser.Gnss;
+using NmeaParser.Messages;
+
+namespace SampleApp.WinDesktop
+{
+    /// <summary>
+    /// Interaction logic for GnssMonitorView.xaml
+    /// </summary>
+    public partial class GnssMonitorView : UserControl
+	{
+		public GnssMonitorView()
+		{
+			InitializeComponent();
+		}
+
+		public GnssMonitor Monitor
+		{
+			get { return (GnssMonitor)GetValue(MonitorProperty); }
+			set { SetValue(MonitorProperty, value); }
+		}
+
+		public static readonly DependencyProperty MonitorProperty =
+			DependencyProperty.Register(nameof(Monitor), typeof(GnssMonitor), typeof(GnssMonitorView), new PropertyMetadata(null, (d,e) => ((GnssMonitorView)d).OnMonitorPropertyChanged(e)));
+
+        private void OnMonitorPropertyChanged(DependencyPropertyChangedEventArgs e)
+        {
+            if (e.OldValue is GnssMonitor oldMonitor)
+            {
+                oldMonitor.LocationChanged -= LocationChanged;
+                oldMonitor.LocationLost -= LocationChanged;
+            }
+            if (e.NewValue is GnssMonitor newMonitor)
+            {
+                newMonitor.LocationChanged += LocationChanged;
+                newMonitor.LocationLost += LocationChanged;
+            }
+            UpdateValues();
+        }
+
+        private void LocationChanged(object sender, System.EventArgs e)
+        {
+            Dispatcher.Invoke(UpdateValues);
+        }
+        private void UpdateValues()
+        { 
+            if (Monitor == null)
+                Values.ItemsSource = null;
+            else
+            {
+                var props = Monitor.GetType().GetProperties(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public);
+                List<KeyValuePair<string, object>> values = new List<KeyValuePair<string, object>>();
+                foreach (var prop in props.OrderBy(t => t.Name))
+                {
+                    if (prop.Name == nameof(GnssMonitor.AllMessages)) continue;
+                    if (prop.PropertyType.IsSubclassOf(typeof(NmeaMessage)))
+                        continue;
+                    var value = prop.GetValue(Monitor);
+                    if (!(value is string) && value is System.Collections.IEnumerable arr)
+                    {
+                        var str = "[" + string.Join(",", arr.OfType<object>().ToArray()) + "]";
+                        if (str.Length == 2)
+                            str = "[ ]";
+                        value = str;
+                    }
+                    values.Add(new KeyValuePair<string, object>(prop.Name, value));
+                }
+                Values.ItemsSource = values;
+            }
+        }        
+    }
+}

src/SampleApp.WinDesktop/GsaControl.xaml.cs

@@ -37,7 +37,10 @@ namespace SampleApp.WinDesktop
 
         private void OnGsaPropertyChanged(DependencyPropertyChangedEventArgs e)
         {
-			vehicles.Value = string.Join(",", Message?.SatelliteIDs);
+			if (Message == null)
+				vehicles.Value = null;
+			else
+				vehicles.Value = string.Join(",", Message?.SatelliteIDs);
         }
     }
 }

src/SampleApp.WinDesktop/MainWindow.xaml

@@ -20,7 +20,7 @@
     </Window.Resources>
     <Grid>
         <TabControl>
-            <TabItem Header="GPS Info">
+            <TabItem Header="Messages">
                 <ScrollViewer HorizontalScrollBarVisibility="Disabled" Background="#FFEEEEEE">
                     <WrapPanel x:Name="MessagePanel">
                         <local:RmcControl x:Name="gprmcView" Style="{StaticResource card}" Visibility="{Binding Message, ElementName=gprmcView, Converter={StaticResource nullConv}}" />
@@ -42,13 +42,16 @@
                     <local:SatelliteSnr Grid.Row="1" x:Name="satSnr" />
                 </Grid>
             </TabItem>
+            <TabItem Header="GNSS Monitor">
+                <local:GnssMonitorView x:Name="gnssMonitorView" />
+            </TabItem>
             <TabItem Header="Map">
                 <local:View2D x:Name="view2d" />
             </TabItem>
             <TabItem Header="3D">
                 <local:View3D x:Name="view3d" />
             </TabItem>
-            <TabItem Header="Messages">
+            <TabItem Header="NMEA Log">
                 <TextBox x:Name="output"
                  AcceptsReturn="True"
                  IsReadOnly="True"

src/SampleApp.WinDesktop/MainWindow.xaml.cs

@@ -1,4 +1,5 @@
-using System;
+using NmeaParser.Gnss;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -15,6 +16,7 @@ namespace SampleApp.WinDesktop
     {
         private Queue<string> messages = new Queue<string>(101);
         public static NmeaParser.NmeaDevice currentDevice;
+
         //Dialog for browsing to nmea log files
         private Microsoft.Win32.OpenFileDialog nmeaOpenFileDialog = new Microsoft.Win32.OpenFileDialog()
         {
@@ -53,6 +55,7 @@ namespace SampleApp.WinDesktop
                 if (currentDevice.IsOpen)
                     await currentDevice.CloseAsync();
                 currentDevice.Dispose();
+                gnssMonitorView.Monitor = null;
             }
             output.Text = "";
             messages.Clear();
@@ -78,6 +81,7 @@ namespace SampleApp.WinDesktop
                     ((NmeaParser.SerialPortDevice)device).Port.BaudRate);
             }
             await device.OpenAsync();
+            gnssMonitorView.Monitor = new GnssMonitor(device);            
         }
 
         private void device_MessageReceived(object sender, NmeaParser.NmeaMessageReceivedEventArgs args)

src/SampleApp.WinDesktop/NmeaLocationDataSource.cs

@@ -1,120 +1,87 @@
-using Esri.ArcGISRuntime.Geometry;
+//  *******************************************************************************
+//  *  Licensed under the Apache License, Version 2.0 (the "License");
+//  *  you may not use this file except in compliance with the License.
+//  *  You may obtain a copy of the License at
+//  *
+//  *  http://www.apache.org/licenses/LICENSE-2.0
+//  *
+//  *   Unless required by applicable law or agreed to in writing, software
+//  *   distributed under the License is distributed on an "AS IS" BASIS,
+//  *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  *   See the License for the specific language governing permissions and
+//  *   limitations under the License.
+//  ******************************************************************************
+
 using System;
 using System.Threading.Tasks;
+using Esri.ArcGISRuntime.Geometry;
+using NmeaParser.Gnss;
 
 namespace SampleApp.WinDesktop
 {
     public class NmeaLocationDataSource : Esri.ArcGISRuntime.Location.LocationDataSource
     {
         private static SpatialReference wgs84_ellipsoidHeight = SpatialReference.Create(4326, 115700);
-        private readonly NmeaParser.NmeaDevice m_device;
+        private readonly GnssMonitor m_gnssMonitor;
-        private double m_Accuracy = 0;
+        private readonly bool m_startStopDevice;
-        private double m_altitude = double.NaN;
+        private double lastCourse = 0; // Course can fallback to NaN, but ArcGIS Datasource don't allow NaN course, so we cache last known as a fallback
-        private double m_speed = 0;
-        private double m_course = 0;
-        private bool m_startStopDevice;
-        private bool m_supportGNMessages; // If device detect GN* messages, ignore all other Talker ID
-        private bool m_supportGGaMessages; //If device support GGA, ignore RMC for location
 
-        public NmeaLocationDataSource(NmeaParser.NmeaDevice device, bool startStopDevice = true)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NmeaLocationDataSource"/> class.
+        /// </summary>
+        /// <param name="device">The NMEA device to monitor</param>
+        /// <param name="startStopDevice">Whether starting this datasource also controls the underlying NMEA device</param>
+        public NmeaLocationDataSource(NmeaParser.NmeaDevice device, bool startStopDevice = true) : this(new GnssMonitor(device), startStopDevice)
         {
-            if (device == null)
+        }
-                throw new ArgumentNullException(nameof(device));
+
-            this.m_device = device;
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NmeaLocationDataSource"/> class.
+        /// </summary>
+        /// <param name="monitor">The NMEA device to monitor</param>
+        /// <param name="startStopDevice">Whether starting this datasource also controls the underlying NMEA device</param>
+        public NmeaLocationDataSource(NmeaParser.Gnss.GnssMonitor monitor, bool startStopDevice = true)
+        {
+            if (monitor == null)
+                throw new ArgumentNullException(nameof(monitor));
+            this.m_gnssMonitor = monitor;
             m_startStopDevice = startStopDevice;
         }
 
-        void device_MessageReceived(object sender, NmeaParser.NmeaMessageReceivedEventArgs e)
+        protected async override Task OnStartAsync()
         {
-            var message = e.Message;
+            m_gnssMonitor.LocationChanged += OnLocationChanged;
-            ParseMessage(message);
+            m_gnssMonitor.LocationLost += OnLocationChanged;
-        }
+            if (m_startStopDevice && !this.m_gnssMonitor.Device.IsOpen)
-        public void ParseMessage(NmeaParser.Messages.NmeaMessage message)
+                await this.m_gnssMonitor.Device.OpenAsync();
-        {
-            bool isNewFix = false;
-            bool lostFix = false;
-            double lat = 0;
-            double lon = 0;
-            if (message.TalkerId == NmeaParser.Talker.GlobalNavigationSatelliteSystem)
-                m_supportGNMessages = true;
-            else if(m_supportGNMessages && message.TalkerId != NmeaParser.Talker.GlobalNavigationSatelliteSystem)
-                    return; // If device supports combined GN* messages, ignore non-GN messages
 
-            if (message is NmeaParser.Messages.Garmin.Pgrme rme)
+            if (m_gnssMonitor.IsFixValid)
-            {
+                OnLocationChanged(this, EventArgs.Empty);
-                m_Accuracy = rme.HorizontalError;
-            }
-            else if(message is NmeaParser.Messages.Gst gst)
-            {
-                Gst = gst;
-                m_Accuracy = Math.Round(Math.Sqrt(Gst.SigmaLatitudeError * Gst.SigmaLatitudeError + Gst.SigmaLongitudeError * Gst.SigmaLongitudeError), 3);
-            }
-            else if (message is NmeaParser.Messages.Rmc rmc)
-            {
-                Rmc = rmc;
-                if (Rmc.Active)
-                {
-                    m_speed = double.IsNaN(Rmc.Speed) ? 0 : Rmc.Speed;
-                    if (!double.IsNaN(Rmc.Course))
-                        m_course = Rmc.Course;
-                    lat = Rmc.Latitude;
-                    lon = Rmc.Longitude;
-                }
-                else
-                {
-                    lostFix = true;
-                }
-                isNewFix = !m_supportGGaMessages;
-            }
-            else if (message is NmeaParser.Messages.Gga gga)
-            {
-                m_supportGGaMessages = true;
-                if (gga.Quality != NmeaParser.Messages.Gga.FixQuality.Invalid)
-                {
-                    lat = gga.Latitude;
-                    lon = gga.Longitude;
-                    m_altitude = gga.Altitude + gga.GeoidalSeparation; //Convert to ellipsoidal height
-                }
-                if (gga.Quality == NmeaParser.Messages.Gga.FixQuality.Invalid || gga.Quality == NmeaParser.Messages.Gga.FixQuality.Estimated)
-                {
-                    lostFix = true;
-                }
-                isNewFix = true;
-            }
-            else if (message is NmeaParser.Messages.Gsa gsa)
-            {
-                Gsa = gsa;
-            }
-            if (isNewFix)
-            {
-                base.UpdateLocation(new Esri.ArcGISRuntime.Location.Location(
-                    !double.IsNaN(m_altitude) ? new MapPoint(lon, lat, m_altitude, wgs84_ellipsoidHeight) : new MapPoint(lon, lat, SpatialReferences.Wgs84),
-                    m_Accuracy, m_speed, m_course, lostFix));
-            }
-        }
-
-        protected override Task OnStartAsync()
-        {
-            m_device.MessageReceived += device_MessageReceived;
-            if (m_startStopDevice)
-                return this.m_device.OpenAsync();
-            else
-                return System.Threading.Tasks.Task<bool>.FromResult(true);
         }
 
         protected override Task OnStopAsync()
         {
-            m_device.MessageReceived -= device_MessageReceived;
+            m_gnssMonitor.LocationChanged -= OnLocationChanged;
-            m_Accuracy = double.NaN;
+            m_gnssMonitor.LocationLost -= OnLocationChanged;
             if(m_startStopDevice)
-                return this.m_device.CloseAsync();
+                return m_gnssMonitor.Device.CloseAsync();
             else
-                return System.Threading.Tasks.Task<bool>.FromResult(true);
+                return Task.CompletedTask;
         }
 
-        public NmeaParser.Messages.Gsa Gsa { get; private set; }
+        private void OnLocationChanged(object sender, EventArgs e)
-        public NmeaParser.Messages.Gga Gga { get; private set; }
+        {
-        public NmeaParser.Messages.Rmc Rmc { get; private set; }
+            if (double.IsNaN(m_gnssMonitor.Longitude) || double.IsNaN(m_gnssMonitor.Latitude)) return;
-        public NmeaParser.Messages.Gst Gst { get; private set; }
+            if (!double.IsNaN(m_gnssMonitor.Course))
+                lastCourse = m_gnssMonitor.Course;
+            UpdateLocation(new Esri.ArcGISRuntime.Location.Location(
+                timestamp: null,
+                position: !double.IsNaN(m_gnssMonitor.Altitude) ? new MapPoint(m_gnssMonitor.Longitude, m_gnssMonitor.Latitude, m_gnssMonitor.Altitude, wgs84_ellipsoidHeight) : new MapPoint(m_gnssMonitor.Longitude, m_gnssMonitor.Latitude, SpatialReferences.Wgs84),
+                horizontalAccuracy: m_gnssMonitor.HorizontalError,
+                verticalAccuracy: m_gnssMonitor.VerticalError,
+                velocity: double.IsNaN(m_gnssMonitor.Speed) ? 0 : m_gnssMonitor.Speed * 0.51444444,
+                course: lastCourse,
+                !m_gnssMonitor.IsFixValid));
+        }
     }
 }