Can't parse some kind of messages

[stm32h757]

Hello,

I can parse the AIS message below using an online decoder successfully:

!AIVDM,2,1,9,B,56SvJh800000CLm0000d<O?3340000000000000k0000012<0;4jkl<t<<Di,0*0E"

However, when using this library, I am unable to parse the same message.

[stm32h757]

Below is an example of a video with an unparsed sentence:

https://youtu.be/bPHIUscOTzA?si=PcVVgNP9Q1WS-WiG

I created a C# code example on visual studio and recorded a video.

Here is the code:

using AisParser;

namespace TestingAISParserLibrary
{
    public partial class Form1 : Form
    {

        Parser myParser;

        public Form1()
        {
            myParser = new Parser();
            InitializeComponent();
        }

        private void buttonParseGood_Click(object sender, EventArgs e)
        {
            var result = myParser.Parse("!AIVDM,1,1,,B,8>lEM?@0Bj0JekdLUe`:SQqG:`vL@0<p0000C90000000000000000l0c00,2*39");
            textBoxGoodSentenceResult.Text = result.ToString();
        }

        private void buttonParseBad_Click(object sender, EventArgs e)
        {
            var result = myParser.Parse("!AIVDM,2,1,9,B,56SvJh800000CLm0000d<O?3340000000000000k0000012<0;4jkl<t<<Di,0*0E");
            textBoxBadResult.Text = "first";
            if (result != null)
            {
                textBoxBadResult.Text = result.ToString();
            }
            else
            {
                textBoxBadResult.Text = "Result is null.";
            }
        }
    }
}

[stm32h757]

I found "Static and Voyage related data message test code" like below.

in this example code, It seems that the first of static and voyage related data should be null.(not contain data) and just store datas in class instance. I'm not sure.

using AisParser;
using AisParser.Messages;
using Shouldly;
using Xunit;

namespace AisParserTests.MessagesTests
{
    public class StaticAndVoyageRelatedDataMessageTests : MessageTestBase
    {
        [Fact]
        public void Should_parse_message()
        {
            const string sentence1 = "!AIVDM,2,1,1,B,53P<GC`000038D5c>01LThi=E10iV2222222220m1P834v2@044kmE20CD53,0*25";
            const string sentence2 = "!AIVDM,2,2,1,B,k`888000000,2*25";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(235083598u);
            message.AisVersion.ShouldBe(2u);
            message.ImoNumber.ShouldBe(0u);
            message.CallSign.ShouldBe("2EAZ3");
            message.ShipName.ShouldBe("WILLSUPPLY");
            message.ShipType.ShouldBe(ShipType.PortTender);
            message.DimensionToBow.ShouldBe(12u);
            message.DimensionToStern.ShouldBe(8u);
            message.DimensionToPort.ShouldBe(3u);
            message.DimensionToStarboard.ShouldBe(4u);
            message.PositionFixType.ShouldBe(PositionFixType.Undefined2);
            message.EtaMonth.ShouldBe(8u);
            message.EtaDay.ShouldBe(4u);
            message.EtaHour.ShouldBe(16u);
            message.EtaMinute.ShouldBe(0u);
            message.Draught.ShouldBe(1.6d);
            message.Destination.ShouldBe("SOUTHAMPTON");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_another_message()
        {
            const string sentence1 = "!AIVDM,2,1,0,A,58wt8Ui`g??r21`7S=:22058<v05Htp000000015>8OA;0sk,0*7B";
            const string sentence2 = "!AIVDM,2,2,0,A,eQ8823mDm3kP00000000000,2*5D";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(603916439u);
            message.AisVersion.ShouldBe(0u);
            message.ImoNumber.ShouldBe(439303422u);
            message.CallSign.ShouldBe("ZA83R");
            message.ShipName.ShouldBe("ARCO AVON");
            message.ShipType.ShouldBe(ShipType.PassengerNoAdditionalInformation);
            message.DimensionToBow.ShouldBe(113u);
            message.DimensionToStern.ShouldBe(31u);
            message.DimensionToPort.ShouldBe(17u);
            message.DimensionToStarboard.ShouldBe(11u);
            message.PositionFixType.ShouldBe(PositionFixType.Undefined1);
            message.EtaMonth.ShouldBe(3u);
            message.EtaDay.ShouldBe(23u);
            message.EtaHour.ShouldBe(19u);
            message.EtaMinute.ShouldBe(45u);
            message.Draught.ShouldBe(13.2d);
            message.Destination.ShouldBe("HOUSTON");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_incomplete_message()
        {
            const string sentence = "!AIVDM,1,1,,A,5815AE82DP=uKLPkT004j0l5<Q84800000000017AcS?T0,4*63";

            var message = Parser.Parse(sentence) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(538005844u);
            message.AisVersion.ShouldBe(2u);
            message.ImoNumber.ShouldBe(9732319u);
            message.CallSign.ShouldBe("V7HL9");
            message.ShipName.ShouldBe("AL MASHRAB");
            message.ShipType.ShouldBe(ShipType.CargoHazardousCategoryA);
            message.DimensionToBow.ShouldBe(141u);
            message.DimensionToStern.ShouldBe(227u);
            message.DimensionToPort.ShouldBe(15u);
            message.DimensionToStarboard.ShouldBe(36u);
            message.PositionFixType.ShouldBe(PositionFixType.Undefined1);
            message.EtaMonth.ShouldBe(0u);
            message.EtaDay.ShouldBe(0u);
            message.EtaHour.ShouldBe(0u);
            message.EtaMinute.ShouldBe(0u);
            message.Draught.ShouldBe(0d);
            message.Destination.ShouldBeEmpty();
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_message_with_nil_eta_1()
        {
            const string sentence1 = "!AIVDM,2,1,6,A,539`vQ400000@SGKGP0P4q<D5@000000000000150@@23t0Ht0B0C@UDQh00,0*6B";
            const string sentence2 = "!AIVDM,2,2,6,A,00000000000,2*22";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(211435140u);
            message.AisVersion.ShouldBe(1u);
            message.ImoNumber.ShouldBe(0u);
            message.CallSign.ShouldBe("DH5658");
            message.ShipName.ShouldBe("HANSEAT");
            message.ShipType.ShouldBe(ShipType.PassengerNoAdditionalInformation);
            message.DimensionToBow.ShouldBe(2u);
            message.DimensionToStern.ShouldBe(16u);
            message.DimensionToPort.ShouldBe(2u);
            message.DimensionToStarboard.ShouldBe(3u);
            message.PositionFixType.ShouldBe(PositionFixType.Undefined2);
            message.EtaMonth.ShouldBe(0u);
            message.EtaDay.ShouldBe(0u);
            message.EtaHour.ShouldBe(24u);
            message.EtaMinute.ShouldBe(60u);
            message.Draught.ShouldBe(0.1d);
            message.Destination.ShouldBe("HAMBURG");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_message_with_nil_eta_2()
        {
            const string sentence1 = "!AIVDM,2,1,8,A,539I@g400000@;W3;B0@EA@lE:1@4pf3G5v0001I9P963t000011@TUL<><<,0*0B";
            const string sentence2 = "!AIVDM,2,2,8,A,13hjn<<<==@,2*0E";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(211177660u);
            message.AisVersion.ShouldBe(1u);
            message.ImoNumber.ShouldBe(0u);
            message.CallSign.ShouldBe("DB9024");
            message.ShipName.ShouldBe("DETTMER TANK 51_");
            message.ShipType.ShouldBe(ShipType.TankerNoAdditionalInformation);
            message.DimensionToBow.ShouldBe(76u);
            message.DimensionToStern.ShouldBe(9u);
            message.DimensionToPort.ShouldBe(6u);
            message.DimensionToStarboard.ShouldBe(3u);
            message.PositionFixType.ShouldBe(PositionFixType.Undefined2);
            message.EtaMonth.ShouldBe(0u);
            message.EtaDay.ShouldBe(0u);
            message.EtaHour.ShouldBe(0u);
            message.EtaMinute.ShouldBe(0u);
            message.Draught.ShouldBe(0d);
            message.Destination.ShouldBe("DEBRU00800DOCKX00045");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_message_libais_30()
        {
            const string sentence1 = "!AIVDM,2,1,3,B,55NBjP01mtGIL@CW;SM<D60P5Ld000000000000P0`<3557l0<50@kk@,0*66";
            const string sentence2 = "!AIVDM,2,2,3,B,K5h@00000000000,2*72";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(367309440u);
            message.AisVersion.ShouldBe(0u);
            message.ImoNumber.ShouldBe(7729526u);
            message.CallSign.ShouldBe("WDD9287");
            message.ShipName.ShouldBe("SEA HAWK");
            message.ShipType.ShouldBe(ShipType.TowingLarge);
            message.DimensionToBow.ShouldBe(5u);
            message.DimensionToStern.ShouldBe(12u);
            message.DimensionToPort.ShouldBe(3u);
            message.DimensionToStarboard.ShouldBe(5u);
            message.PositionFixType.ShouldBe(PositionFixType.Gps);
            message.EtaMonth.ShouldBe(4u);
            message.EtaDay.ShouldBe(15u);
            message.EtaHour.ShouldBe(20u);
            message.EtaMinute.ShouldBe(0u);
            message.Draught.ShouldBe(4.8d);
            message.Destination.ShouldBe("TACOMA,WA");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }

        [Fact]
        public void Should_parse_message_libais_32()
        {
            const string sentence1 = "!AIVDM,2,1,1,A,55>u@H02;lGc<Ha;L0084i<7GR22222222222216:PE885AU0A4l13H13kBC,0*3D";
            const string sentence2 = "!AIVDM,2,2,1,A,R@hC`4QD;`0,2*06";

            Parser.Parse(sentence1).ShouldBeNull();
            var message = Parser.Parse(sentence2) as StaticAndVoyageRelatedDataMessage;

            message.ShouldNotBeNull();
            message.MessageType.ShouldBe(AisMessageType.StaticAndVoyageRelatedData);
            message.Repeat.ShouldBe(0u);
            message.Mmsi.ShouldBe(351228000u);
            message.AisVersion.ShouldBe(0u);
            message.ImoNumber.ShouldBe(9163130u);
            message.CallSign.ShouldBe("3FJR7");
            message.ShipName.ShouldBe("BALSA58");
            message.ShipType.ShouldBe(ShipType.Cargo);
            message.DimensionToBow.ShouldBe(84u);
            message.DimensionToStern.ShouldBe(21u);
            message.DimensionToPort.ShouldBe(8u);
            message.DimensionToStarboard.ShouldBe(8u);
            message.PositionFixType.ShouldBe(PositionFixType.Gps);
            message.EtaMonth.ShouldBe(5u);
            message.EtaDay.ShouldBe(3u);
            message.EtaHour.ShouldBe(5u);
            message.EtaMinute.ShouldBe(0u);
            message.Draught.ShouldBe(6.8d);
            message.Destination.ShouldBe("SPDM DOMINICAN REP.");
            message.DataTerminalReady.ShouldBeTrue();
            message.Spare.ShouldBe(0u);
        }
    }
}

[chrisrichards]

Yes, the message is the first of a two part message. It should decode once you supply the second message.