bertoldvdb/go-ais

Automatic Identification System (ITU-R M.1371-5) packet decoder and encoder written in Go

go-ais's Issues

Handle multipart messages

Looks like this package is having issues with multi part messages. This test can be added to nmea_test.go to show the issue:

func TestMultiMessage(t *testing.T) {
	nm := NMEACodecNew(ais.CodecNew(false, false))
	_, err := nm.ParseSentence("!AIVDM,2,1,0,B,539S:k40000000c3G04PPh63<00000000080000o1PVG2uGD:00000000000,0*34\n!AIVDM,2,2,0,B,00000000000,2*27")

	if err != nil {
		t.Error(err)
		t.Error("Can't handle multipart message")
	}
}

PositionReport.RateOfTurn is I3, which is different than int8.

The PositionReport struct defines RateOfTurn as int8. This precludes the value of 128, which is used for "no turn information available". The source of the problem is a difference in interpretation of an AIS data type. Eric Raymond's documentation for AIVDM messages defines this field as I3, which, if I'm understanding correctly, means "signed three digit decimal integer", which could (and does) have values that don't fit into an int8.

How decode !AIVDM,2,1,0,B,C8tLui00029?mqShpr=M9:v0<bf2,0*57 & !AIVDM,2,2,0,B,L?eQQUeKWeKgS;1001@50Q2P,0*78?

Megre PR that adds support for NMEA 4.10 TAG Blocks in aisnmea convenience library

Hi @BertoldVdb

Could we please discuss merging #1 ?

Thanks!
-Simeon.

how to decode message type 5?Looks like this package is having issues with multi part messages

Failure to decode some static data reports

go-ais fails decode a number of Static Data Report (type 24) messages that I am able to decode using other AIS decoders. Example code is shown below. DecodePacket returns null for all of the failed messages.

package main

import (
	"encoding/json"
	"fmt"
	"github.com/BertoldVdb/go-ais"
	"github.com/adrianmo/go-nmea"
	"log"
	"time"
)

func scanMessages() {
	sentences := []string{
		// A couple of good (decodable) messages for reference
		"\\s:66,c:1636156800*34\\!AIVDM,1,1,,,34hA4u0P00PDW7BMeJJPCOwn23U3,0*54",
		"\\s:66,c:1636156800*34\\!AIVDM,1,1,,,14eGsMw000G;;U0KdwfaBG`02400,0*17",
		// All of these remaining messages fail to decode
		// Although they all decode successfully using http://ais.tbsalling.dk/
		"\\s:66,c:1635752275*3D\\!AIVDM,1,1,,,HpuGhQ5G653hhhiJBniqnP02@0p,2*57",
		"\\s:66,c:1635784819*36\\!AIVDM,1,1,,,Hcwo0G?8=aOCkl`k:v?Flhve4@7`,0*79",
		"\\s:66,c:1635794719*38\\!AIVDM,1,1,,,HofeSn4U653hhhi5mEjnqh03008,2*17",
		"\\s:66,c:1635801587*3E\\!AIVDM,1,1,,,H6`U8m=<0oes>>g8j6UEmPR9wNdk,0*42",
		"\\s:66,c:1635801603*31\\!AIVDM,1,1,,,Hks<bFcb:7HFeVsm8D:qA:20Njai,0*62",
		"\\s:66,c:1635801633*32\\!AIVDM,1,1,,,H>LKae;muCahwBwtHgNcFrehwKEI,0*46",
		"\\s:66,c:1635801699*32\\!AIVDM,1,1,,,HHsNBIsW<cSVppkL3v>@otg@=QsT,0*44",
		"\\s:66,c:1635801743*34\\!AIVDM,1,1,,,Hv?eMg<jmmwN=gowL94@DRwmOULj,0*35",
		"\\s:66,c:1635801787*3C\\!AIVDM,1,1,,,HudKH=Nwv7JW@fVi;IbV`i?Gs1la,0*04",
		"\\s:66,c:1635801845*3D\\!AIVDM,1,1,,,H3w65Weu;U4biowGKqdo2dNp8R:b,0*4A",
		"\\s:66,c:1635807283*3B\\!AIVDM,1,1,,,Hq9D:bH?J9nvT8ptm>C1aqrGN8:L,0*0B",
		"\\s:66,c:1635807331*33\\!AIVDM,1,1,,,HsqF@Nw4PKaa9t8=lT;V?=4RG2MS,0*2F",
		"\\s:66,c:1636157735*3C\\!AIVDM,1,1,,,Hfdmqq`JtNMtbj<kKS`sfKfwusw?,0*4F",
		"\\s:66,c:1636185526*33\\!AIVDM,1,1,,,HmBhv256>hhhhhh8@nkoj005@0l,2*42",
		"\\s:66,c:1636185666*34\\!AIVDM,1,1,,,HofeSn4U653hhhi5mEjnqh03008,2*17",
		"\\s:66,c:1636201729*31\\!AIVDM,1,1,,,HG`k1qf?Vw=k5fHphLpcw;>cvdl;,0*05",
		"\\s:66,c:1636206977*33\\!AIVDM,1,1,,,HopN@TK<n?W45I49N4J9@2ljdpn0,0*69",
		"\\s:66,c:1636207057*39\\!AIVDM,1,1,,,HQ>s17u4NBTBw`wVBANq>hGGdMEu,0*2B",
		"\\s:66,c:1636207065*38\\!AIVDM,1,1,,,H:`AD`KLUSb2B=OQ5=L9rkSW;1ej,0*45",
		"\\s:66,c:1636234777*3C\\!AIVDM,1,1,,,HW<AV>;Wvk8M:ObuVLaqdB1gVvT1,0*34",
		"\\s:66,c:1636234779*32\\!AIVDM,1,1,,,HVuEL8tf<kS60UTb4Be@H?1im@ls,0*00",
		"\\s:66,c:1636234783*37\\!AIVDM,1,1,,,H?O5=MuFtu@PJsJc28TrC4THnl7:,0*60",
		"\\s:66,c:1636234798*3D\\!AIVDM,1,1,,,HCNiwp<d<4Ghd2Cp2kNmh6NAf9nW,0*1B",
		"\\s:66,c:1636234803*30\\!AIVDM,1,1,,,Hfr<;DcJ7o@ccqc`tnanMImBVSrQ,0*23",
		"\\s:66,c:1636234875*31\\!AIVDM,1,1,,,HRu6baIn`@VVPNg9I0;`bnbiNrtA,0*56",
		"\\s:66,c:1636234889*32\\!AIVDM,1,1,,,HO9G<hfhWWlD>J4QU>t5o06hbO77,0*7B",
		"\\s:66,c:1636234937*36\\!AIVDM,1,1,,,H3uVqHJ<4d9D6ldUEb=3BW;sUU42,0*44",
		"\\s:66,c:1636234953*34\\!AIVDM,1,1,,,HVep8kw<A>WKCo;OG92=3GL26NCG,0*48",
		"\\s:66,c:1636235011*3A\\!AIVDM,1,1,,,HawEMMpEkTTa7wfQmmWbBkH<ASV9,0*21",
		"\\s:66,c:1636235071*3C\\!AIVDM,1,1,,,H6do9?tAlK94dUB4Keainou4UmK=,0*64",
		"\\s:66,c:1636235165*38\\!AIVDM,1,1,,,H2JTKGccrJe19rw=UQ<n2uV682sM,0*27",
		"\\s:66,c:1636235245*39\\!AIVDM,1,1,,,HqN;>M8EFTrLlwKRMuvH7@D6;Md<,0*26",
	}

	c := ais.CodecNew(false, false)
	c.DropSpace = true

	for _, sentence := range sentences {
		s, err := nmea.Parse(sentence)
		if err != nil {
			log.Fatalf("parsing error %d\n", err)
		}
		parsed := s.(nmea.VDMVDO)
		log.Printf("TAG Block timestamp: %v\n", time.Unix(parsed.TagBlock.Time, 0))
		log.Printf("TAG Block source:    %v\n", parsed.TagBlock.Source)

		msg := parsed.Payload
		result := c.DecodePacket(msg)
		out, _ := json.MarshalIndent(result, "", "  ")
		fmt.Printf("%T: %s\n", result, out)
	}
}

func main() {
	scanMessages()
}

typo in messages.go

There is a typo in 2 field names in StaticDataReportB
https://github.com/BertoldVdb/go-ais/blob/master/messages.go#L306-L307

s/vender/vendor/