Marine motion sensor IMU-00X

Motion Reference Unit IMU-00x IMU-00x
Roll, pitch, heave, velocities and
accelerations motion sensor.
Model Roll/Pitch Heave
IMU-007 0.25° RMS N/A
IMU-008 0.25° RMS 5cm or 5%

The marine motion sensor IMU-00x series is SMC’s compact and rugged product range designed for Marine installations and optimized for Dynamic Positioning, Vessel Motion, winch heave compensation as well as hydrographic systems. Solid state gyros and linear accelerometers are used in the IMU-00x motion sensors to provide real time motion measurements with precise dynamic accuracy.


SMC's IMU-00x motion sensor range is small and compact in its design. The motion sensor body height is 7cm with the mounting plate base measured 13x13 cm.

Marine Motion Sensor Marine Motion sensor dimensions


From initial development to final design SMC has taken account of the specific hazards and environmental factors of the Marine offshore environment. Durability, low maintenance, ease of install for out of the box installation without the need for add-on purchases. The IMU once installed should be reliable and a secure source of data.

Titanium Material

The casing material used in all of our IMU-series is Titanium. The most useful properties of Titanium are its high strength, low density and corrosion resistance in the Marine environments the motion sensor works in.

Mounting plate

The IMU-00x marine motion sensor is designed with a mounting plate as a part of its casing. This base plate has been specially designed for ease of installation and by allowing a freedom of movement around the mounting fixings an accurate mechanical alignment can be made that is critical for good motion performance and accuracy.

See Accessories for additional mounting bracket options.

Marine Motion Sensor mounting plate

Subsea Marine Motion Sensor IP68

The IMU-008 and IMU-007 are available as submersible motion sensors, depth rated for 30 meters. The submersible versions of the SMC motion sensors are using the Seacon Wet Mate Connector with IP68 classification for continual immersion in water.

Marine Motion Sensor subsea connector

Marine Motion Sensor IP66

The marine motion sensor IMU-008 and IMU-007 are designed for surface installations. The motion sensor is fitted with the Amphenol Lite IP66 rated connector. The connector on the motion sensor is a standard available part with a long term supply. This makes it easy for the IMU motion sensor users to source the cable and connector from SMC or other suppliers. The IP66 classification protects the IMU from direct water jet spays or general external harsh weather installations.

Marine Motion Sensor Standard connector

Components and processing

The SMC marine motion sensors use solid state MEMS rate gyros that offer low noise and high accuracy as well as providing excellent vibration performance and long life reliability.

Three separate axial measurement component groups made of Gyroscopes, Accelerometers and Magnetometers are mounted in three axis for X, Y and Z measurements. The signal from the gyroscopes are combined with the signal from the accelerometers and magnetometers and are processed in a Kalman filter inside the motion sensor to provide output value for acceleration, attitude and angle with limited influence from accelerations, noise and other inaccuracies.

Heave is computed from a double integration of the acceleration into a linear position. The integration is further processed and filtered for an accurate heave measurement during dynamic environment.


As a standard all SMC marine motion sensors have 1 x RS232 and 1 x RS422 communication ports enabling the selection of Industry standard and bespoke output protocols. For aiding and data inputs 2 x RS232 serial ports are available. Ethernet connection is available as factory option, UDP output. Update Rates of 1 to 100Hz and 9600 to 115200 baud rates for selected protocols.

Aiding from Compass and GPS

SMC motion sensors can use inputs for aiding from standard industry GPS or Compass systems already installed on a vessel to improve measurement results during vessel turns. This is particularly useful during hydrographic surveying where performance can be maintained during quick turns.

AHC Crane encoder feedback

Unique to SMC motion sensor is our SMC Active heave compensation AHC encoder feedback option developed in conjunction with Bosch Rexroth drives but available for all users. The SMC AHC system accepts dynamic crane encoder position data for dynamic active heave compensation in marine crane applications.

Motion Sensor Configuration software

The SMC marine motion sensor configuration software has been developed with ease of use and the different industry users in mind. An uncluttered display with separate control pages, the SMC motion sensor configuration tools enable any user to understand and carry out a motion sensor installation with the minimal of fuss.

Motion Sensor Protocols

Knowing that the motion sensors are used in multiple fields with multiple separate equipment’s and systems as many user selectable protocols and standard strings have been installed as default in the motion sensors which makes the motion sensor compatible with most applications on the market.

Calibration of Marine Motion Sensor

Each motion sensor is calibrated prior to delivery. The motion sensors are thoroughly tested in the SMC facilities before and during the calibration process. The calibration is performed in a 2-axis rate table with a temperature controlled chamber. The calibration process is fully automated and runs for three days with a controlled temperature environment over the full temperature range.

All motion sensors are calibrated individually and the readings from the accelerometers and angular rate gyroscopes are verified for alignment, linearity and temperature, to ensure they meet the performance specifications.

Technical specifications

Technical specifications IMU-007 IMU-008
Roll/Pitch Yes Yes
Accelerations X, Y, Z Yes Yes
Heave N/A Yes
Angle Accuracy static 0.2° RMS 0.2° RMS
Angle Accuracy Dynamic
@ ±5° simultaneous roll and pitch
0.25° RMS 0.25° RMS
Resolution Angle 0.001° 0.001°
Resolution Heave N/A 0.01m
Angle range Roll/Pitch ±30° ±30°
Heave range N/A ±10m
Heave Accuracy N/A 5cm or 5%
Acceleration accuracy 0.05 m/s² RMS 0.05 m/s² RMS
IMU Configuration Software The IMU is shipped with SMC configuration windows software allowing on site setup
Output Signal Protocol Multiple, user selectable Output Protocols ASCII NMEA and binary
Communications Interface Output RS422 and RS232. Analog with remote converter (optional)
2 x RS232 External inputs, (not available on all models)
Velocity input formats RMC, RMA, VTG, VBV, VHW; Heading input formats HDT, HDG
Dimensions for IMU-00x (W x H) tube Ø89 mm, mounting plate Ø134 mm, flange Ø110 mm x 67 mm excl. connector
Weight ~0.5 kg
Housing Material Titanium
Temperature (absolute max) 0° to +55° Celsius (-10° to +65°); Storage Temperature -40° to +65° Celsius
Mounting Orientation Vertical or Horizontal mounting (factory set)
Power requirements 12 - 30 VDC; 2 W
MTBF (computed) 50 000 hours
Depth rating IP66 (standard); IP68 30 meter depth rated (optional)
Standard Complies with the IEC 60945
Warranty & Support      
Warranty 2-year Limited Hardware & Software Warranty
Support Free Technical & Hardware support
Bundled Delivery      
Junction Box Multiple Input & Output Connection Case, including 10 m cable


IMU-00x Motion Sensor Datasheet

SMC IMU Manual

316L Enclosure datasheet

GRP Enclosure datasheet

SMC IMU Configuration software