Motion Reference Unit (MRU)

Product Summary

motion sensor for hydrography , Motion Reference Units MRU-B
Dual Antenna

underwater subsea motion sensor, Motion Reference Units, MRU



heave motion ship sensor, Motion Reference Units, MRU


professional heave and pitch sensor marine, Motion Reference Unit, MRU



GPS ship position heave sensor, Motion Reference Unit, MRU

Input data DVL (Doppler Velocity Log)
Output data Pitch, Roll, Roll Velocity, Pitch Velocity, Surge, Sway, Heave, Surge Velocity, Sway Velocity, Heave Velocity,
Acceleration X, Acceleration Y, Acceleration Z, Gyro X, Gyro Y, Gyro Z
Models with GNSS receiver: position (DGPS, RTK), Heading, PPS time, Linear velocity
Heave accuracy 5% / 5cm 5% / 5cm 5% / 5cm 5% / 5cm
Pitch & Roll accuracy 0.02 deg 0.02 deg 0.02 deg 0.02 deg
Heading accuracy (embedded) 0.6 deg 0.4 deg 0.05 deg
Position accuracy (embedded) 40 cm (DGPS)
1 cm (RTK)
40 cm (DGPS)
1 cm (RTK)
Interface RS-232, RS-422, Ethernet
Output data format Kongsberg/Seatex, SMC, TSS1, Binary, NMEA 0183 ASCII characters

Motion Reference Units key performance

Heave accuracy at 10 seconds wave

plot heave mru high accuracy

Heave accuracy at 20 seconds wave

heave error calculation for motion

Pitch dynamic accuracy at 20 sec wave

dynamic pitch plot error marine

Roll dynamic accuracy at 20 sec wave

roll graph marine vessel

MRU Heave, Pitch & Roll dynamic testing

MRU Gyroscopes & Accelerometers Bias in-run stability

dynamic surge and sway average

dynamically positioned vessel imu

The Inertial Labs has developed Motion Reference Units (MRU) to meet requirements from marine and hydrographic applications. MRU is enhanced, high-performance strapdown Motion Sensor, that determines Pitch & Roll, Heave, Sway, Surge, Accelerations, Angular rates, Heading, Velocity and Positions for any device on which it is mounted. The Inertial Labs Motion Reference Units utilizes solid state 3-axes each of precision accelerometers, magnetometers, gyroscopes and barometric sensors to provide accurate Heave, Sway, Surge, Pitch and Roll of the device under measure.

Integration of very low noise gyroscopes output provides high frequency, real-time measurement of the Vessel, Ships, Helidecks, ROV, Marine antennas, Cranes rotation about all three rotational axes.

Through a combination of proven sector expertise and a continued investment in technological innovation, Inertial Labs delivers the optimum balance of price and performance ratio solutions for its customers.

Our MRUs featuring developed few micro g Bias in-run stability Micro Electro Mechanical System (MEMS)-based accelerometers. New generation of Inertial Labs 1 deg/hr Bias in-run stability MEMS-based gyroscopes are an ideal solution for demanding marine applications, with their electronic nature negating the problems associated with expensive mechanical gyro solutions, as well as those based on fiber optic (FOG) technology.

Inertial Labs MEMS gyroscopes set the standard for the industry, with our high-end MRUs featuring gyros that enable sector-leading accuracy and reliability standards.

Applications and Customer Cases for MRU

MRU Certificate of Design Assessment

Representatives of the American Bureau of Shipping assessed design plans and data of all Inertial Labs MRU products. This assessment is a representation by the Bureau as to the degree of compliance the design exhibits with applicable sections of their Rules. This PDA is intended for a product to be installed on an ABS classed vessel, MODU or facility which is in existence or under contract for construction.

Certificate number 19-HS1851412-PDA

Date 10 May 2019

ABS approval sensor

Established in 2001, Inertial Labs is a leader in position and orientation technologies for commercial, industrial, aerospace and defense applications. Inertial Labs has a worldwide distributor and representative network covering 20+ countries across 6 continents delivering compact, high performance and affordable Miniature Orientation Sensors, Motion Reference Units (MRU), Attitude & Heading Reference Systems (AHRS) and GPS-Aided Inertial Navigation Systems (INS). With application breadth on Land, Air, and Sea; Inertial Labs covers the gambit of inertial technologies and solutions. Contact us to learn more.