3DM
®
-GX5-10
User Manual
Delta-Theta
the time integral of angular rate expressed with refernce to the device local coordinate system, in units
of radians
Delta-velocity
the time integral of velocity expressed with refernce to the device local coordinate system, in units of
g*second where g is the standard gravitational constant
E
ECEF (Earth Centered Earth Fixed)
a reference frame that is fixed to the earth at the center of the earth and turning about earth's axis in the
same way as the earth
Estimation Filter
A mathematical algorithm that produces a statistically optimum solution using measurements and ref-
erences from multiple sources. Best known estimation filters are the Kalman Filter, Adaptive Kalman
Filter, and Extended Kalman Filter.
Euler angles
Euler angles are three angles use to describe the orientation of an object in space such as the x, y and z
or pitch; roll; and yaw. Euler angles can also represent a sequence of three elemental rotations around
the axes of a coordinate system.
Extended Kalman Filter (EKF)
Used generically to describe any estimation filter based on the Kalman Filter model that can handle
non-linear elements. Almost all inertial estimation filters are fundamentally EKFs.
G
GNSS (Global Navigation Statellite System)
a global network of space based statellites (GPS, GLONASS, BeiDou, Galileo, and others) used to tri-
angulate position co-ordinates and provide time information for navigational purposes
GPS (Global Positioning System)
a U.S. based network of space based statellites used to triangulate position co-ordinates and provide
time information for navigational purposes
Gyroscope
a device used to sense angular movements such as rotation
H
Heading
an object's direction of travel with reference to a co-ordinate frame, such as lattitude and longitude
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