#
# GNSS ECEF and LLA navigation solution with uncertainty.
#

#
# Global network-synchronized time, if available, otherwise zero.
#
uavcan.Timestamp timestamp

#
# Time solution.
# The method and number of leap seconds which were in use for deriving the timestamp are
# defined in the fields below.
#
uavcan.Timestamp gnss_timestamp

#
# Method used for deriving the GNSS timestamp field.
# This data type relies on the following definitions:
#
#   Leap seconds  - Accumulated one-second adjustments applied to UTC since 1972.
#                   For reference, on May 2017, the number of leap seconds was equal 27.
#                   The number of leap seconds is taken from the field num_leap_seconds.
#                   Refer to https://en.wikipedia.org/wiki/Leap_second for a general overview.
#
#   TAI timestamp - The number of microseconds between the current TAI time and
#                   the TAI time at UTC 1970-01-01T00:00:00.
#
#   UTC timestamp - The number of microseconds between the current UTC time and
#                   UTC 1970-01-01T00:00:00.
#                   UTC can be expressed via TAI as follows (in seconds):
#                       UTC = TAI - num_leap_seconds - 10
#                   And via GPS (in seconds):
#                       UTC = GPS - num_leap_seconds + 9
#
#   GPS timestamp - The number of microseconds between the current GPS time and
#                   the GPS time at UTC 1970-01-01T00:00:00.
#                   GPS time can be expressed via TAI as follows (in seconds):
#                       GPS = TAI - 19
#
uint3 GNSS_TIME_STANDARD_NONE = 0  # Time is unknown
uint3 GNSS_TIME_STANDARD_TAI  = 1
uint3 GNSS_TIME_STANDARD_UTC  = 2
uint3 GNSS_TIME_STANDARD_GPS  = 3
uint3 gnss_time_standard

void13   # Reserved space

#
# Accumulated one-second adjustments applied to UTC since 1972.
# The number must agree with the currently correct number of UTC leap seconds. If this cannot
# be garanteed, the field must be set to NUM_LEAP_SECONDS_UNKNOWN.
#
uint8 NUM_LEAP_SECONDS_UNKNOWN = 0
uint8 num_leap_seconds

#
# Position and velocity solution
#
int37 longitude_deg_1e8            # Longitude degrees multiplied by 1e8 (approx. 1 mm per LSB)
int37 latitude_deg_1e8             # Latitude degrees multiplied by 1e8 (approx. 1 mm per LSB on equator)
int27 height_ellipsoid_mm          # Height above ellipsoid in millimeters
int27 height_msl_mm                # Height above mean sea level in millimeters

float32[3] ned_velocity            # NED frame (north-east-down) in meters per second

#
# Fix status
#
uint6 sats_used

uint2 STATUS_NO_FIX    = 0
uint2 STATUS_TIME_ONLY = 1
uint2 STATUS_2D_FIX    = 2
uint2 STATUS_3D_FIX    = 3
uint2 status

#
# GNSS Mode
#
uint4 MODE_SINGLE      = 0
uint4 MODE_DGPS        = 1
uint4 MODE_RTK         = 2
uint4 MODE_PPP         = 3
uint4 mode

#
# GNSS Sub mode
#
uint6 SUB_MODE_DGPS_OTHER    = 0
uint6 SUB_MODE_DGPS_SBAS     = 1

uint6 SUB_MODE_RTK_FLOAT     = 0
uint6 SUB_MODE_RTK_FIXED     = 1

uint6 sub_mode

#
# Precision
#
float16[<=36] covariance    # Position and velocity covariance. Units are
                            # m^2 for position, (m/s)^2 for velocity and
                            # m^2/s for position/velocity.

float16 pdop

#
# Position and velocity solution in ECEF, if available
#
ECEFPositionVelocity[<=1] ecef_position_velocity