North Finding

Problem We Solve

Common north finding modules embed a 3-axis magnetometer. Such a sensor measures the angle between the pointing direction of the system and the magnetic field of the Earth. Magnetometers are cheap and small, however they show some weaknesses. First and foremost, this type of sensors measures the magnetic north, leading to an error to adjust. Secondly, its accuracy is greatly reduced when the sensor is surrounded by magnetic elements.

Advanced north finding modules are using a gyroscopic compass instead of a magnetometer. Gyroscopes measure angular velocity relative to its inertial position. A 2-axis gyroscope can find north, and a 3-axis gyroscope detects the Earth’s axis of rotation. There are many types of gyroscopes, based on different principles:

• Classic Mechanical – Spinning wheel mounted on a gimbal
• Optical – Fiber optic gyros (FOGFiber Optic Gyroscope. Uses the interference of light to detect mechanical rotation. See also) and Ring Laser GyroDevice for measuring or maintaining orientation, based on the principles of angular momentum. See also (RLGRing Laser Gyroscope. Uses interference of laser light within an optical ring to detect changes in orientation and spin. See also), based on the Sagnac effect
• Vibrating – Coriolis effect – Hemispheric Resonating Gyros (HRG), Micromechanical Gyros (MEMSMicroElectroMechanical System. See also)

The gyroscopes measure true north and are not affected by external magnetic fields or surrounding metals but they are affected by Bias drift.

Why it is Important

North finding is critical for tactical navigation and target orientation localization. It is used either in fixed static observation systems or in hand-held portable devices.

How We Solve it

Designed to address advanced, tactical grade inertial applications, the MS1000 is a new class of high performance accelerometers, based on Safran Colibrys’ 25-year MEMS development and production expertise.

MS1000 implements an innovative microelectromechanical design and electronics which unleash unbeatable performances with regard to the long term bias and scale factor repeatability, in-run bias and vibration rectification error (VRE).

MS1000 is available in a rich set of g-ranges +/-2, 5, 10, 30, 100g and is qualified for volume production.

Why Choose Us

The MS1000 is specifically designed for inertial applications. Its excellent long term bias and scale factor repeatability, low in-run bias, excellent behavior in vibration (VRE) and low noise allow very accurate and cost-effective tactical grade measurements. The internal electronic circuit integrates a signal conditioning with a differential analog ± 2.7V output, a Built- in SelfTest, and a temperature sensor for compensation.

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