This message presents the estimated state of the vehicle.
EstimatedState is a complete description of the system in terms of parameters such as position, orientation and velocities at a particular moment in time.
The system position is given by a NorthEastDown (NED) local tangent plane displacement (x, y, z) relative to an absolute WGS84 coordinate (latitude, longitude, height above ellipsoid).
The symbols for position and attitude as well as linear and angular velocities were chosen according to SNAME’s notation (1950). The bodyfixed reference frame and Euler angles are depicted next:
Euler angles
Name  Abbreviation  Unit  Type  Description  Range 

Latitude (WGS84)  lat  rad  fp64_t  WGS84 Latitude.  min=1.5707963267948966, max=1.5707963267948966 
Longitude (WGS84)  lon  rad  fp64_t  WGS84 Longitude.  min=3.141592653589793, max=3.141592653589793 
Height (WGS84)  height  m  fp32_t  Height above the WGS84 ellipsoid.  Same as field type 
Offset north  x  m  fp32_t  The North offset of the North/East/Down field with respect to LLH.  Same as field type 
Offset east  y  m  fp32_t  The East offset of the North/East/Down field with respect to LLH.  Same as field type 
Offset down  z  m  fp32_t  The Down offset of the North/East/Down field with respect to LLH.  Same as field type 
Rotation over x axis  phi  rad  fp32_t  The phi Euler angle from the vehicle’s attitude.  min=3.141592653589793, max=3.141592653589793 
Rotation over y axis  theta  rad  fp32_t  The theta Euler angle from the vehicle’s attitude.  min=1.57079632679490, max=1.57079632679490 
Rotation over z axis  psi  rad  fp32_t  The psi Euler angle from the vehicle’s attitude.  min=3.141592653589793, max=3.141592653589793 
BodyFixed xx Velocity  u  m/s  fp32_t  Bodyfixed frame xx axis velocity component.  Same as field type 
BodyFixed yy Velocity  v  m/s  fp32_t  Bodyfixed frame yy axis velocity component.  Same as field type 
BodyFixed zz Velocity  w  m/s  fp32_t  Bodyfixed frame zz axis velocity component.  Same as field type 
Ground Velocity X (North)  vx  m/s  fp32_t  Ground Velocity xx axis velocity component.  Same as field type 
Ground Velocity Y (East)  vy  m/s  fp32_t  Ground Velocity yy axis velocity component.  Same as field type 
Ground Velocity Z (Down)  vz  m/s  fp32_t  Ground Velocity zz axis velocity component.  Same as field type 
Angular Velocity in x  p  rad/s  fp32_t  The angular velocity over bodyfixed xx axis (roll).  min=3.141592653589793, max=3.141592653589793 
Angular Velocity in y  q  rad/s  fp32_t  The angular velocity over bodyfixed yy axis (pitch).  min=3.141592653589793, max=3.141592653589793 
Angular Velocity in z  r  rad/s  fp32_t  The angular velocity over bodyfixed zz axis (yaw).  min=3.141592653589793, max=3.141592653589793 
Depth  depth  m  fp32_t  Depth, in meters. To be used by underwater vehicles. Negative values denote invalid estimates.  Same as field type 
Altitude  alt  m  fp32_t  Altitude, in meters. Negative values denote invalid estimates.  Same as field type 
The estimated stream velocity, typically for water or air streams.
Name  Abbreviation  Unit  Type  Description  Range 

X component (North)  x  m/s  fp64_t  X component (North).  Same as field type 
Y component (East)  y  m/s  fp64_t  Y component (East).  Same as field type 
Z component (Down)  z  m/s  fp64_t  Z component (Down).  Same as field type 
Speed measured by the navigation filter.
Name  Abbreviation  Unit  Type  Description  Range 

Measured speed  value  m/s  fp64_t  Same as field type 
Ground true speed.
Name  Abbreviation  Unit  Type  Description  Range 

Estimated value  value  m/s  fp64_t  Same as field type 
Report of navigation uncertainty. This is usually given by the output of the state covariance matrix of an Extended Kalman Filter.
Name  Abbreviation  Unit  Type  Description  Range 

Variance  x Position  x  m  fp32_t 

Same as field type 
Variance  y Position  y  m  fp32_t 

Same as field type 
Variance  z Position  z  m  fp32_t 

Same as field type 
Variance  Roll  phi  rad  fp32_t  The phi Euler angle variance from the vehicle’s attitude.  Same as field type 
Variance  Pitch  theta  rad  fp32_t  The theta Euler angle variance from the vehicle’s attitude.  Same as field type 
Variance  Yaw  psi  rad  fp32_t  The psi Euler angle variance from the vehicle’s attitude.  Same as field type 
Variance  Gyro. Roll Rate  p  rad/s  fp32_t  The angular velocity variance over bodyfixed xx axis (roll).  Same as field type 
Variance  Gyro. Pitch Rate  q  rad/s  fp32_t  The angular velocity variance over bodyfixed yy axis (pitch).  Same as field type 
Variance  Gyro. Yaw Rate  r  rad/s  fp32_t  The angular velocity variance over bodyfixed zz axis (yaw).  Same as field type 
Variance  BodyFixed xx Velocity  u  m/s  fp32_t  Bodyfixed frame xx axis velocity variance component.  Same as field type 
Variance  BodyFixed yy Velocity  v  m/s  fp32_t  Bodyfixed frame yy axis velocity variance component.  Same as field type 
Variance  BodyFixed ww Velocity  w  m/s  fp32_t  Bodyfixed frame zz axis velocity variance component.  Same as field type 
Variance  Yaw Bias  bias_psi  rad  fp32_t  The psi Euler angle bias variance from the vehicle’s sensed attitude.  Same as field type 
Variance  Gyro. Yaw Rate Bias  bias_r  rad/s  fp32_t  The angular velocity over bodyfixed zz axis bias variance from sensor.  Same as field type 
Report of navigation data. This is constituted by data which is not part of the vehicle estimated state but that the user may refer for more information.
Name  Abbreviation  Unit  Type  Description  Range 

Yaw Bias  bias_psi  rad  fp32_t  The psi Euler angle bias from the vehicle’s sensed attitude.  Same as field type 
Gyro. Yaw Rate Bias  bias_r  rad/s  fp32_t  The angular velocity over bodyfixed zz axis bias from sensor.  Same as field type 
Course Over Ground  cog  rad  fp32_t  Course over ground given by NED ground velocity vectors.  Same as field type 
Continuous Yaw  cyaw  rad  fp32_t  Continuous psi Euler angle (without normalizations).  Same as field type 
GPS Rejection Filter Level  lbl_rej_level    fp32_t  GPS rejection filter level.  Same as field type 
LBL Rejection Filter Level  gps_rej_level    fp32_t  LBL rejection filter level.  Same as field type 
Variance  Custom Variable X  custom_x    fp32_t  Custom variable.  Same as field type 
Variance  Custom Variable Y  custom_y    fp32_t  Custom variable.  Same as field type 
Variance  Custom Variable Z  custom_z    fp32_t  Custom variable.  Same as field type 
No description
Name  Abbreviation  Unit  Type  Description  Range 

UTC Time of Fix  utc_time  s  fp32_t  UTC time of the rejected GPS fix measured in seconds since 00:00:00 (midnight).  Same as field type 
Reason  reason  Enumerated (Enum Reason)  uint8_t  Reason for rejection.  Same as field type 
Reason for rejection.
Value  Name  Abbreviation  Description 

0  Above Threshold  ABOVE_THRESHOLD  New GPS Fix position is above a computed threshold. 
1  Invalid Fix  INVALID  Invalid measurement. 
2  Above Maximum HDOP  ABOVE_MAX_HDOP  Above maximum horizontal dilution of precision. 
3  Above Maximum HACC  ABOVE_MAX_HACC  Above maximum horizontal accuracy index. 
4  Lost Validity Bit  LOST_VAL_BIT  Lost one of the validity bits between consecutive GPS fixes. 
When the vehicle uses Long Base Line navigation, this message notifies that a new range was received from one of the acoustics transponders. The message fields are used to identify the range value and the transponder name. Also, this message has an acceptance field that indicates whether a LBL range was accepted or rejected, and if rejected, the reason why.
Name  Abbreviation  Unit  Type  Description  Range 

Beacon Identification Number  id    uint8_t  Identification number of the acoustic transponder from which the range information was received.  Same as field type 
Range  range  m  fp32_t  Distance to the acoustic transponder.  Same as field type 
Acceptance  acceptance  Enumerated (Enum Acceptance)  uint8_t  Reason for acceptance/rejection.  Same as field type 
Reason for acceptance/rejection.
Value  Name  Abbreviation  Description 

0  Accepted  ACCEPTED  This LBL range is accepted by the navigation filter. 
1  Rejected  Above Threshold  ABOVE_THRESHOLD  New LBL Range is above a computed threshold. 
2  Rejected  Singular Point  SINGULAR  Singular point. 
3  Rejected  Not Enough Information  NO_INFO  The filter lacks information to properly use the received LBL range. 
4  Rejected  Vehicle At Surface  AT_SURFACE  Vehicle is using only GPS fix when it is at surface. 
When the vehicle uses Doppler Velocity Log sensor, this message notifies that a new measurement was locally rejected by the navigation filter.
Name  Abbreviation  Unit  Type  Description  Range 

Type of velocity  type  Bitfield (Bitfield Type of velocity)  uint8_t  This field represents the type of the rejected velocity.  Same as field type 
Reason  reason  Enumerated (Enum Reason)  uint8_t  Reason for rejection. There are two types of DVL measurement filters. An Innovation filter checks the innovation between the current measurement and the previous measurement within a certain amount of time and an Absolute filter compares the measurement with an absolute threshold value. Those filters are tested using horizontal speed measurements, i.e., measurements in the xaxis and in the yaxis.  Same as field type 
Value  value  m/s  fp32_t  Value of the rejection. If it is an innovation rejection the value is the absolute difference between the previous accepted DVL measurement and the current one. If it is an absolute rejection the value is the current DVL measurement.  Same as field type 
Timestep  timestep  s  fp32_t  Timestep of the rejection. The timestep is 0 for an absolute rejection since it is an instantaneous reading. For innovation rejection it is the time difference between the previous accepted DVL measurement and the current one.  Same as field type 
This field represents the type of the rejected velocity.
Value  Name  Abbreviation  Description 

0x01  Ground velocity  GV   
0x02  Water velocity  WV   
Reason for rejection. There are two types of DVL measurement filters. An Innovation filter checks the innovation between the current measurement and the previous measurement within a certain amount of time and an Absolute filter compares the measurement with an absolute threshold value. Those filters are tested using horizontal speed measurements, i.e., measurements in the xaxis and in the yaxis.
Value  Name  Abbreviation  Description 

0  Innovation Threshold  X  INNOV_THRESHOLD_X  The current DVL xaxis measurement is discarded because the absolute difference between the value and the previous accepted DVL measurement with a given time window is above a configurable threshold. 
1  Innovation Threshold  Y  INNOV_THRESHOLD_Y  The current DVL yaxis measurement is discarded because the absolute difference between the value and the previous accepted DVL measurement with a given time window is above a configurable threshold. 
2  Absolute Threshold  X  ABS_THRESHOLD_X  The current DVL xaxis measurement is discarded because the the absolute value is above a configurable threshold. 
3  Absolute Threshold  Y  ABS_THRESHOLD_Y  The current DVL yaxis measurement is discarded because the the absolute value is above a configurable threshold. 
LBL Beacon position estimate.
Name  Abbreviation  Unit  Type  Description  Range 

LBL Beacon Configuration  beacon    message (LBL Beacon Configuration)  LBL Beacon configuration estimate.  Same as field type 
North position  x  m  fp32_t  The North position offset of the NED field with respect to origin.  Same as field type 
East position  y  m  fp32_t  The East position offset of the NED field with respect to origin.  Same as field type 
North position variance  var_x  m  fp32_t  The North offset variance of the North/East/Down field with respect to LLH.  Same as field type 
East position variance  var_y  m  fp32_t  The East offset variance of the North/East/Down field with respect to LLH.  Same as field type 
Distance  distance  m  fp32_t  Distance between current LBL Beacon position and filter estimation.  Same as field type 
This message notifies the vehicle is ready for deadreckoning missions.
Name  Abbreviation  Unit  Type  Description  Range 

State  state  Enumerated (Enum State)  uint8_t  Alignment State.  Same as field type 
Alignment State.
Value  Name  Abbreviation  Description 

0  Not Aligned  NOT_ALIGNED   
1  Aligned  ALIGNED   
2  Not Supported  NOT_SUPPORTED   
3  Aligning  ALIGNING   
4  Wrong Medium  WRONG_MEDIUM   
5  Coarse Alignment  COARSE_ALIGNMENT   
6  Fine Alignment  FINE_ALIGNMENT   
7  System Ready  SYSTEM_READY   
The stream velocity estimated by a group of systems. Typically for water or air streams.
Name  Abbreviation  Unit  Type  Description  Range 

X component (North)  x  m/s  fp64_t  X component (North).  Same as field type 
Y component (East)  y  m/s  fp64_t  Y component (East).  Same as field type 
Z component (Down)  z  m/s  fp64_t  Z component (Down).  Same as field type 
Airspeed along with airflow angles.
Name  Abbreviation  Unit  Type  Description  Range 

Airspeed  va  m/s  fp32_t  Airspeed, the 2norm of the relative velocity.  Same as field type 
Angle of attack  aoa  rad  fp32_t  Angle of attack.  Same as field type 
Sideslip angle  ssa  rad  fp32_t  Sideslip angle.  Same as field type 