/* Copyright (c) 2011 Danish Maritime Authority.
*
* 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.
*/
package dk.dma.ais.message;
import dk.dma.ais.binary.BinArray;
import dk.dma.ais.binary.SixbitEncoder;
import dk.dma.ais.binary.SixbitException;
import dk.dma.ais.sentence.Vdm;
import dk.dma.enav.model.geometry.Position;
/**
* AIS position message
*
* An AIS position message is defined by ITU-R M.1371-4 in annex 8 - AIS messages section 3.1
*
* This is a generalization for message types 1-3 and possibly more in the future.
*
* Type 1: Scheduled position report (Class A shipborne mobile equipment) Type 2: Assigned scheduled position report
* (Class A shipborne mobile equipment) Type 3: Special position report, response to interrogation;(Class A shipborne
* mobile equipment)
*
*/
public abstract class AisPositionMessage extends AisMessage implements IVesselPositionMessage {
/** serialVersionUID. */
private static final long serialVersionUID = 1L;
/**
* Navigational status: 0 = under way using engine 1 = at anchor 2 = not under command 3 = restricted
* manoeuvrability 4 = constrained by her draught 5 = moored 6 = aground 7 = engaged in fishing 8 = under way
* sailing 9 = reserved for future amendment of navigational status for ships carrying DG, HS, or MP, or IMO hazard
* or pollutant category C, high speed craft (HSC), 10 = reserved for future amendment of navigational status for
* ships carrying dangerous goods (DG), harmful substances (HS) or marine pollutants (MP), or IMO hazard or
* pollutant category A, wing in grand (WIG); 11-13 = reserved for future use 14 = AIS-SART (active) 15 = not
* defined = default (also used by AIS-SART under test)
*/
protected int navStatus; // 4 bits
/**
* Rate of Turn (ROT): 0 to +126 = turning right at up to 708 degrees per min or higher 0 to -126 = turning left at
* up to 708 degrees per min or higher Values between 0 and 708 degrees per min coded by ROTais = 4.733
* SQRT(ROTsensor) degrees per min where ROTsensor is the Rate of Turn as input by an external Rate of Turn
* Indicator (TI). ROTais is rounded to the nearest integer value.
*
* +127 = turning right at more than 5 degrees per 30 s (No TI available) -127 = turning left at more than 5 degrees
* per 30 s (No TI available) -128 (80 hex) indicates no turn information available (default).
*
* ROT data should not be derived from COG information.
*/
protected int rot; // 8 bits :
/**
* Speed Over Ground Speed over ground in 1/10 knot steps (0-102.2 knots) 1023 = not available, 1022 = 102.2 knots
* or higher
*/
protected int sog; // 10 bits
/**
* AisPosition Accuracy: The position accuracy (PA) flag should be determined in accordance with Table 47 1 = high (
* =< 10 m) 0 = low (>10 m) 0 = default
*/
protected int posAcc; // 1 bit
/**
* Stores the positions in a general manner
*/
protected AisPosition pos; // : Lat/Long 1/10000 minute
/**
* Course over Ground Course over ground in 1/10 = (0-3599). 3600 (E10h) = not available = default. 3601-4095 should
* not be used
*/
protected int cog; // 12 bits
/**
* True heading Degrees (0-359) (511 indicates not available = default)
*/
protected int trueHeading; // 9 bits
/**
* Time stamp: UTC second when the report was generated by the EPFS (0-59 or 60 if time stamp is not available,
* which should also be the default value or 61 if positioning system is in manual input mode or 62 if electronic
* position fixing system operates in estimated (dead reckoning) mode or 63 if the positioning system is
* inoperative) 61, 62, 63 are not used by CS AIS
*/
protected int utcSec; // 6 bits : UTC Seconds
/**
* Special manoeuvre indicator: 0 = not available = default 1 = not engaged in special manoeuvre 2 = engaged in
* special manoeuvre (i.e.: regional passing arrangement on Inland Waterway)
*
* NOTE: This field is added in ITU-R M1371-4
*/
protected int specialManIndicator; // 2 bits
/**
* Not used. Should be set to zero. Reserved for future use.
*
* NOTE: In ITU-R M1371-4 this field is 3 bits compared to 1 previously
*/
protected int spare; // 3 bits
/**
* RAIM-flag: Receiver autonomous integrity monitoring (RAIM) flag of electronic position fixing device; 0 = RAIM
* not in use = default; 1 = RAIM in use. See Table 47
*/
protected int raim; // 1 bit : RAIM flag
/**
* SOTDMA/ITDMA sync state: sync state is part of the defined communication state (19) bits. The sync state is the
* first 2 bits of the 19 bits in the communication state of the message.
*
* 0 UTC direct (see 3.1.1.1) 1 UTC indirect (see 3.1.1.2) 2 Station is synchronized to a base station (base direct)
* 3 Station is synchronized to another station based on the highest number of received stations or to another
* mobile station, which is directly synchronized to a base station
*/
protected int syncState; // 2 bits
public AisPositionMessage(int msgId) {
super(msgId);
}
public AisPositionMessage(Vdm vdm) {
super(vdm);
}
public void parse(BinArray binArray) throws AisMessageException, SixbitException {
if (binArray.getLength() < 168) {
throw new AisMessageException("Message " + msgId + " wrong length: " + binArray.getLength());
}
super.parse(binArray);
/* Parse the pos Message */
this.navStatus = (int) binArray.getVal(4);
this.rot = (int) binArray.getVal(8);
this.sog = (int) binArray.getVal(10);
this.posAcc = (int) binArray.getVal(1);
this.pos = new AisPosition();
this.pos.setRawLongitude(binArray.getVal(28));
this.pos.setRawLatitude(binArray.getVal(27));
this.cog = (int) binArray.getVal(12);
this.trueHeading = (int) binArray.getVal(9);
this.utcSec = (int) binArray.getVal(6);
this.specialManIndicator = (int) binArray.getVal(2);
this.spare = (int) binArray.getVal(3);
this.raim = (int) binArray.getVal(1);
this.syncState = (int) binArray.getVal(2);
}
/*
* (non-Javadoc)
*
* @see dk.frv.ais.message.AisMessage#encode()
*/
@Override
protected SixbitEncoder encode() {
SixbitEncoder encoder = super.encode();
encoder.addVal(navStatus, 4);
encoder.addVal(rot, 8);
encoder.addVal(sog, 10);
encoder.addVal(posAcc, 1);
encoder.addVal(pos.getRawLongitude(), 28);
encoder.addVal(pos.getRawLatitude(), 27);
encoder.addVal(cog, 12);
encoder.addVal(trueHeading, 9);
encoder.addVal(utcSec, 6);
encoder.addVal(specialManIndicator, 2);
encoder.addVal(spare, 3);
encoder.addVal(raim, 1);
encoder.addVal(syncState, 2);
return encoder;
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append(super.toString());
builder.append(", cog=");
builder.append(cog);
builder.append(", navStatus=");
builder.append(navStatus);
builder.append(", pos=");
builder.append(pos);
builder.append(", posAcc=");
builder.append(posAcc);
builder.append(", raim=");
builder.append(raim);
builder.append(", specialManIndicator=");
builder.append(specialManIndicator);
builder.append(", rot=");
builder.append(rot);
builder.append(", sog=");
builder.append(sog);
builder.append(", spare=");
builder.append(spare);
builder.append(", syncState=");
builder.append(syncState);
builder.append(", trueHeading=");
builder.append(trueHeading);
builder.append(", utcSec=");
builder.append(utcSec);
return builder.toString();
}
public int getNavStatus() {
return navStatus;
}
public void setNavStatus(int navStatus) {
this.navStatus = navStatus;
}
public int getRot() {
return rot;
}
public Float getSensorRot() {
if (rot == 128) {
return null;
}
int signedRot = (byte)rot;
float sensorRot = (float)Math.pow(signedRot / 4.733, 2);
if (signedRot < 0) {
sensorRot *= -1;
}
return sensorRot;
}
public void setRot(int rot) {
this.rot = rot;
}
public int getSog() {
return sog;
}
public void setSog(int sog) {
this.sog = sog;
}
public int getPosAcc() {
return posAcc;
}
public void setPosAcc(int posAcc) {
this.posAcc = posAcc;
}
@Override
public final Position getValidPosition() {
AisPosition pos = this.pos;
return pos == null ? null : pos.getGeoLocation();
}
public AisPosition getPos() {
return pos;
}
public void setPos(AisPosition pos) {
this.pos = pos;
}
public int getCog() {
return cog;
}
public void setCog(int cog) {
this.cog = cog;
}
public int getTrueHeading() {
return trueHeading;
}
public void setTrueHeading(int trueHeading) {
this.trueHeading = trueHeading;
}
public int getUtcSec() {
return utcSec;
}
public void setUtcSec(int utcSec) {
this.utcSec = utcSec;
}
/**
* @return the specialManIndicator
*/
public int getSpecialManIndicator() {
return specialManIndicator;
}
/**
* @param specialManIndicator
* the specialManIndicator to set
*/
public void setSpecialManIndicator(int specialManIndicator) {
this.specialManIndicator = specialManIndicator;
}
public int getSpare() {
return spare;
}
public void setSpare(int spare) {
this.spare = spare;
}
public int getRaim() {
return raim;
}
public void setRaim(int raim) {
this.raim = raim;
}
public int getSyncState() {
return syncState;
}
public void setSyncState(int syncState) {
this.syncState = syncState;
}
public boolean isPositionValid() {
Position geo = pos.getGeoLocation();
return geo != null;
}
public boolean isCogValid() {
return cog < 3600;
}
public boolean isSogValid() {
return sog < 1023;
}
public boolean isHeadingValid() {
return trueHeading < 360;
}
public boolean isRotValid() {
return rot > -128;
}
}