Package AIS

Class AISDataUnit

java.lang.Object

PamguardMVC.PamDataUnit

AIS.AISDataUnit

All Implemented Interfaces:

Serializable, Cloneable, Comparable

public class AISDataUnit
extends PamDataUnit
implements Serializable, Cloneable

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected String	aisChannel	When provided, the AIS channel is indicated as either "1" or "2." This channel indication is relative to the operating conditions of the transponder when the packet is received.
protected String	charData	Contents of the M.1371 radio message using the six-bit field type
protected String	dataType	AIVDM, etc.
protected int	fillBits	Number of "fill-bits" added to complete the last six-bit character
protected boolean	isInRange	Flag used when a limit is placed on range.
protected int	messageId	Pulled out from the start of the AIVDM string.
int	mmsiNumber
protected boolean	newUnit
protected int	sentenceNumber	Message sentence number
protected int	sequentialIdentifier	The "message sequential identifier" is a number from 0 to 9 that is sequentially assigned as needed.
protected StationType	stationType
protected int	totalSentences	Total number of sentences needed to transfer the message

Fields inherited from class PamguardMVC.PamDataUnit

absBlockIndex, localisation

Constructor Summary

Constructors

Constructor	Description
AISDataUnit(long timeMilliseconds)	Constructor used in data collection - doesn't do much
AISDataUnit(long timeMillis, String charData, int fillBits)	Constructor used when reading back from binary files.

Method Summary

Modifier and Type	Method	Description
void	addPositionReport(AISPositionReport positionReport)
protected AISDataUnit	clone()
boolean	decodeMessage()	Decode the binary data which are currently in a character string
AISPositionReport	findPositionReport(long timeMillis)
AISPositionReport	getPositionReport()
ArrayList<AISPositionReport>	getPositionReports()
AISStaticData	getStaticData()
String	getStationtypeString()
boolean	isComplete()
void	setStaticData(AISStaticData staticData)
void	update(AISDataUnit newAISUnit)	Update an existing AIS data unit with new data.

Methods inherited from class PamguardMVC.PamDataUnit

addDataAnnotation, addSuperDetection, amplifyMeasuredAmplitudeByDB, amplifyMeasuredAmplitudeByLinear, calcSnapshotGeometry, clearOandAngles, clearUpdateCount, compareTo, findDataAnnotation, findDataAnnotation, freeData, getAbsBlockIndex, getAmplitudeDB, getAnnotationsSummaryString, getBasicData, getCalculatedAmlitudeDB, getChannelBitmap, getColourIndex, getDataAnnotation, getDatabaseIndex, getDatabaseUpdateOf, getDataUnitFileInformation, getDataUnitPopupMenu, getDurationInMilliseconds, getEndTimeInMilliseconds, getFrequency, getFrequencyOverlap, getGpsPosition, getHydrophoneBitmap, getHydrophoneHeading, getLastChangeTime, getLastSample, getLastUpdateTime, getLocalisation, getMeasuredAmplitude, getMeasuredAmplitudeType, getNoiseBackground, getNumDataAnnotations, getOriginLatLong, getParentDataBlock, getSampleDuration, getSampleDurationAsInt, getSeconds, getSequenceBitmap, getSequenceBitmapObject, getSignalExcess, getSignalSPL, getSnapshotGeometry, getStartSample, getSummaryString, getSuperDetection, getSuperDetection, getSuperDetection, getSuperDetection, getSuperDetection, getSuperDetectionsCount, getSuperDetectionSyncronisation, getSuperId, getTimeDelaysSeconds, getTimeMilliseconds, getTimeNanoseconds, getTimeOverlap, getUID, getUpdateCount, isEmbryonic, isForceAmpRecalc, linAmplitudeToDB, removeDataAnnotation, removeDataAnnotation, removeSuperDetection, setAbsBlockIndex, setCalculatedAmlitudeDB, setChannelBitmap, setDatabaseIndex, setDatabaseUpdateOf, setDataUnitFileInformation, setDurationInMilliseconds, setEmbryonic, setForceAmpRecalc, setFrequency, setInfo, setLastUpdateTime, setLocalisation, setMeasuredAmpAndType, setMeasuredAmplitude, setMeasuredAmplitudeType, setNoiseBackground, setParentDataBlock, setSampleDuration, setSequenceBitmap, setSignalExcess, setSignalSPL, setSnapshotGeometry, setStartSample, setTimeDelaysSeconds, setTimeMilliseconds, setUID, setUniqueSuperDetection, sortOutputMaps, updateDataUnit

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

isInRange

protected boolean isInRange

Flag used when a limit is placed on range. If it's clearly out of range, then this flag is set and no more updates are made from static data.

the flag can be set false again if new position data come within range.

newUnit

protected boolean newUnit

dataType

protected String dataType

AIVDM, etc.

stationType

protected StationType stationType

messageId

protected int messageId

Pulled out from the start of the AIVDM string.

totalSentences

protected int totalSentences

Total number of sentences needed to transfer the message

sentenceNumber

protected int sentenceNumber

Message sentence number

sequentialIdentifier

protected int sequentialIdentifier

The "message sequential identifier" is a number from 0 to 9 that is sequentially assigned as needed. This identifier is incremented for each new multi-sentence message. The count resets to 0, after 9 is used. For radio broadcast messages requiring multiple sentences, each sentence of the message contains the same sequential identification number. The purpose of this number is to link the separate sentences containing portions of the same radio message. This allows for the possibility that other sentences might be interleaved with the message sentences that contain the complete message contents. This number also links an ABK-sentence acknowledgement to the appropriate BBM-sentence.

aisChannel

protected String aisChannel

When provided, the AIS channel is indicated as either "1" or "2." This channel indication is relative to the operating conditions of the transponder when the packet is received. This field shall be null when the channel identification is not provided.

charData

protected String charData

Contents of the M.1371 radio message using the six-bit field type

The maximum string length of encapsulation is limited such that the total number of sentence characters does not exceed 82. This field supports a maximum of 62 valid characters for messages transferred using multiple sentences, and 63 valid characters for messages using a single sentence.

fillBits

protected int fillBits

Number of "fill-bits" added to complete the last six-bit character

Each character in the preceding six-bit coded character string represents six binary bits. This parameter indicates the number of bits that were added to the end of the binary packet as a result of creating the last character of the string. When the coding of the last six-bit character of the message packet does not create additional "fill-bits," this value shall be set to zero. The value "0" indicates that no "fill-bits" were added. This field may not be null.

mmsiNumber

public int mmsiNumber

Constructor Details

AISDataUnit

public AISDataUnit(long timeMilliseconds)

Constructor used in data collection - doesn't do much

AISDataUnit

public AISDataUnit(long timeMillis,
 String charData,
 int fillBits)

Constructor used when reading back from binary files.

Parameters:

timeMillis - time millis

charData - 6 bit character data string

fillBits - fill bits to ignore at end of string

Method Details

getStationtypeString

public String getStationtypeString()

decodeMessage

public boolean decodeMessage()

Decode the binary data which are currently in a character string

Returns:

true if the message was decoded successfully

isComplete

public boolean isComplete()

update

public void update(AISDataUnit newAISUnit)

Update an existing AIS data unit with new data.

Parameters:

newAISUnit -

clone

protected AISDataUnit clone()

Overrides:

clone in class Object

getPositionReport

public AISPositionReport getPositionReport()

findPositionReport

public AISPositionReport findPositionReport(long timeMillis)

getStaticData

public AISStaticData getStaticData()

getPositionReports

public ArrayList<AISPositionReport> getPositionReports()

addPositionReport

public void addPositionReport(AISPositionReport positionReport)

setStaticData

public void setStaticData(AISStaticData staticData)