3DM-GX4
™
-45
™
Inertial Navigation System
User Manual
Sensor Measurements
26
Measurement
Units
Description
Position (LLH)
degrees (position)
meters (accuracy)
position reported by GPS module only,
expressed in Latitude, Longitude, and Height
(LLH) with accuracy estimation
Velocity (NED)
meters/second
(velocity)
meters (accuracy)
velocity measurement reported by GPS module
only, with reference to North, East, Down
coordinate system and with accuracy estimation
GPS Time
weeks & seconds
time acquired from the satellites
Position (ECEF)
meters
position reported by GPS module only, with ref-
erence to the Earth Centered, Earth Fixed
(ECEF) Cartesian coordinate system
Velocity (ECEF)
meters/second
(velocity)
meters (accuracy)
velocity reported by GPS module only, with ref-
erence to the Earth Centered, Earth Fixed
(ECEF) Cartesian coordinate system
Speed
meters/second
(speed)
meters (accuracy)
speed along direction of travel in 2D and 3D
space as reported by GPS module only
DOP Data
--
Dilution of Precision (DOP) ratings for accuracy
of GPS readings
UTC Data
time and date
Coordinated Universal Time (UTC) to fractional
seconds with leap year seconds adjustment and
confidence indicator. Also week number, month,
date and year.
Clock Information
seconds
clock accuracy metrics
GPS Fix
Information
--
information about the type, quantity and quality
of the satellite connections
Space Vehicle
Information (SVI)
N/A
referred to as Satellite Info, includes satellite
number and signal strength
Hardware Status
--
operational status of GPS receiver and antenna
DGPS Information
--
Individual satellite signal strength indicator
DGPS Channel
Status
--
(future use)
Height
meters
elevation or altitude relative to average sea level
(MSL reading) or height relative to WSG-84
Ellipsoid (AE reading)
Heading (NED)
degrees
heading reported by GPS module only, with
reference to the North, East, Down coordinate
system and with accuracy estimation
Table 5 -
GPS Outputs