MRU 5+

Motion Reference Unit

The MRU 5+ product is upgraded with the best MEMS based gyro technology available. With exceptional low angle noise and bias stability, the product is ideal for integrated INS/GNSS systems and demanding survey applications.

Precision and Reliability

The MRU 5+ provides documented roll and pitch accuracy of 0.008° and angle noise less than 0.002°. Every unit is delivered with an individual calibration certificate documenting this accuracy. This is made possible by use of accurate inertial sensors including three rate gyros and linear accelerometers of excellent tactical navigation grade performance. Very high reliability is achieved by using solid-state sensors with no moving parts and the proven MRU electrical and mechanical construction.

Advanced Motion Sensing Technology

The PFreeHeave algorithm uses past measurements to output a correct and phase-free heave from MRU 5+. It has an advantage in long swell conditions and for applications that can utilize a heave signal that is delayed some minutes, typical for seabed mapping applications. Additionally, a new MEMS based gyro is developed by Kongsberg Seatex AS called MRG5 (Mru Rate Gyro) model 5. The MRG5 is optimized for use in high-end applications. The MRU rate gyro combines very low noise, excellent bias stability and outstanding gain accuracy and is the best MEMS rate gyro available for maritime applications.

Ease of Integration and Application Flexibility

Interfacing the MRU 5+ to various sonar systems is made easy by including data protocols for the most commonly used multibeam echo sounder systems in the software. Using the configuration cable and the Windows version of the configuration software, MRC+, a series of simple menu prompts allow the user to choose the optimum configuration for his application. The MRU 5+ and the MRC+ software are flexible and can accommodate a wide variety of application types.

Key features

  • 0.008° roll and pitch accuracy
  • Exceptional low angle noise and bias stability
  • High output data rate (200 Hz)
  • Outputs on RS-232, RS-422 and Ethernet
  • Precise heave at long wave periods by use of PFreeHeave algorithm
  • Each MRU delivered with Calibration Certificate
  • No limitation in mounting orientation
  • Lever arm compensation to two individually configurable monitoring points
  • Meets IHO special order requirements
  • Small size, light weight, low power consumption
  • 2-year warranty

Technical specifications


Roll/pitch Static RMS:
Roll/pitch Dynamic 1-sigma:
Heave Real-time RMS:
5 cm/5 %
Heave Period Real-time:
25 s
Heave Delayed RMS:
1 cm/1 %
Heave Period Delayed:
50 s

We offer comprehensive after-sales assistance

Find your local dealership

Our global dealership network enables distribution to more than 100 countries to meet customer needs at any location. Find your local dealership here.