3DM-CX5-GNSS/INS
User Manual
16
4.
Sensor Measurements
The 3DM-CX5-GNSS/INS block diagram (
Figure14: 3DM-CX5-GNSS/INS Block Diagram
) describes its
primary hardware components and internal configuration. Integrated Micro-Electro-Mechanical System
(MEMS) sensors within the 3DM-CX5-GNSS/INS are collectively known as the Inertial Measurement
Unit (IMU) and include tri- axial gyroscopes (gyros), tri- axial accelerometers, tri- axial magnetometers,
and a pressure altimeter.
This technology provides direct measurements of acceleration, angular rate, magnetic field, pressure,
Delta-theta (change in angular rate), and Delta-velocity (change in velocity). Temperature and pressure
sensors provide environmental information for measurement compensation and altitude estimations.
GNSS information can be read directly and is also used in the computed navigation estimations.
Information can be read directly but is not used internally for attitude or navigation estimations on the 3DM-
CX5-GNSS/INS.
Computed estimations for position, velocity, and attitude (PVA) are available outputs on the 3DM-CX5-
GNSS/INS. To achieve these estimations, the MEMS sensors and GNSS solution are blended together
in a loosely- coupled Extended Kalman Filter on a dedicated filter processor. Additional user settings such
as measurement filtering, biasing, and tolerance values offer adjustments for specific applications.
Figure 14. 3DM-CX5-GNSS/INS Block Diagram
