org.ka2ddo.opentrac

Class OpenTracGpsQuality

java.lang.Object

org.ka2ddo.opentrac.OpenTracElement

org.ka2ddo.opentrac.OpenTracGpsQuality

All Implemented Interfaces:

java.io.Serializable

public class OpenTracGpsQuality
extends OpenTracElement

This class represents an OpenTRAC data element with the quality information for the entity's GPS fix. It should not be included if the entity's position information was not obtained from a Global Positioning System receiver (any constellation). Also, if none of the information transmitted in this element can be obtained, it would be better to omit this element entirely rather than create one with all values set to unknown.

Author:

Andrew Pavlin, KA2DDO

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
byte	fixType The GPS fix type of the signal.
byte	fixValidity The validity of the current fix.
short	hdop Horizontal Dilution Of Precision of the satellite configuration, multiplied by 10.
byte	numSatellites Number of satellites actually used for the fix as reported by the NMEA 0183 $GPGGA sentence.
short	pdop Position Dilution Of Precision of the satellite configuration, multiplied by 10.
short	vdop Vertical Dilution Of Precision of the satellite configuration, multiplied by 10.

Fields inherited from class org.ka2ddo.opentrac.OpenTracElement

id

Constructor Summary

Constructors

Constructor and Description
OpenTracGpsQuality() Create an uninitialized OpenTracGpsQuality element.
OpenTracGpsQuality(int type, byte[] body, int offset, int length) Extract a OpenTracGpsQuality element from a byte array
OpenTracGpsQuality(int fixType, int fixValidity, int numSatellites) Create an OpenTracGpsQuality element with the specified fix quality.
OpenTracGpsQuality(int fixType, int fixValidity, int numSatellites, float hdop, float pdop, float vdop) Create an OpenTracGpsQuality element with the specified fix quality and DOP.

Method Summary

Modifier and Type	Method and Description
int	computeBody(byte[] buf, int offset) Append this element to a message buffer
boolean	equalsElement(OpenTracElement other) Test if this OpenTracElement has the same type and value as another OpenTracElement.
int	length() Return the number of bytes needed to encode this element.
java.lang.String	valueString() Get the string representation of the value of this element.

Methods inherited from class org.ka2ddo.opentrac.OpenTracElement

getId, toString

Methods inherited from class java.lang.Object

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

Field Detail

fixType

public byte fixType

The GPS fix type of the signal.

Fix type values

value	meaning
0	unknown or not available
1	no position fix
2	2D fix
3	3D fix

fixValidity

public byte fixValidity

The validity of the current fix.

Validity values

value	meaning
0	invalid
1	valid SPS (Standard Positioning Service)
2	value DGPS (Differential GPS)
3	valid PPS

numSatellites

public byte numSatellites

Number of satellites actually used for the fix as reported by the NMEA 0183 $GPGGA sentence.

hdop

public short hdop

Horizontal Dilution Of Precision of the satellite configuration, multiplied by 10. Negative value indicates HDOP is not known. Positive values are clipped at 255 (equivalent of the extremely poor DOP value of 25.5).

pdop

public short pdop

Position Dilution Of Precision of the satellite configuration, multiplied by 10. Negative value indicates PDOP is not known. Positive values are clipped at 255 (equivalent of the extremely poor DOP value of 25.5).

vdop

public short vdop

Vertical Dilution Of Precision of the satellite configuration, multiplied by 10. Negative value indicates VDOP is not known. Positive values are clipped at 255 (equivalent of the extremely poor DOP value of 25.5).

Constructor Detail

OpenTracGpsQuality

public OpenTracGpsQuality()

Create an uninitialized OpenTracGpsQuality element.

OpenTracGpsQuality

public OpenTracGpsQuality(int type,
                          byte[] body,
                          int offset,
                          int length)

Extract a OpenTracGpsQuality element from a byte array

Parameters:

type - OpenTracTypes code for this element

body - byte array to extract element from

offset - zero-based array index to start extraction

length - number of bytes to extract

OpenTracGpsQuality

public OpenTracGpsQuality(int fixType,
                          int fixValidity,
                          int numSatellites)
                   throws java.lang.IllegalArgumentException

Create an OpenTracGpsQuality element with the specified fix quality.

Parameters:

fixType - int fix type code in the range 0 to 3

fixValidity - int fix validity code in the range 0 to 3

numSatellites - int number of satellites in use in the range 0 to 15

Throws:

java.lang.IllegalArgumentException - if fixType, fixQuality, or numSatellites is out of range

OpenTracGpsQuality

public OpenTracGpsQuality(int fixType,
                          int fixValidity,
                          int numSatellites,
                          float hdop,
                          float pdop,
                          float vdop)
                   throws java.lang.IllegalArgumentException

Create an OpenTracGpsQuality element with the specified fix quality and DOP.

Parameters:

fixType - int fix type code in the range 0 to 3

fixValidity - int fix validity code in the range 0 to 3

numSatellites - int number of satellites in use in the range 0 to 15

hdop - float horizontal dilution of precision in the range 0 to 25.5

pdop - float position dilution of precision in the range 0 to 25.5

vdop - float vertical dilution of precision in the range 0 to 25.5

Throws:

java.lang.IllegalArgumentException - if fixType, fixQuality, or numSatellites is out of range

Method Detail

computeBody

public int computeBody(byte[] buf,
                       int offset)

Append this element to a message buffer

Specified by:

computeBody in class OpenTracElement

Parameters:

buf - byte array to add the element to

offset - starting index to store the element

Returns:

index after the end of the stored element

valueString

public java.lang.String valueString()

Get the string representation of the value of this element.

Specified by:

valueString in class OpenTracElement

Returns:

value string

length

public int length()

Return the number of bytes needed to encode this element.

Specified by:

length in class OpenTracElement

Returns:

byte count needed to hold this element

equalsElement

public boolean equalsElement(OpenTracElement other)

Test if this OpenTracElement has the same type and value as another OpenTracElement.

Specified by:

equalsElement in class OpenTracElement

Parameters:

other - OpenTracElement to compare against this element

Returns:

boolean true if elements are of the same type, class, and value