North Finding systems can be used for north finding and target location applications, and sometimes are embedded in Inertial Navigation Systems (INS) for navigation missions. Such an integration requires both low drifts and high sensing range parameters, which usually which usually comes at the expense of each other.
Physical Logic’s Closed-Loop accelerometer meets both parameters with bias drift less than 2.5µg/min after less than 3 minutes from turn on and sensing ranges from 15g to 70g.
A North Finder may be exposed to continuous environmental error sources such as temperature drifts, shocks, vibrations, short term and long-term drifts and aging; therefore, measurement accuracy becomes an issue, especially when measurement starts short time after turn-on and is performed over a long period. The use of an accelerometer for north finding is often required to compensate gyro errors. The accelerometer measures the value of drift which is used for gyro recalibration.
Accelerometer may be also used as a resulting vector for north finding applications in events of rotations while the rotated body is not moving, and the gyro cannot distinguish between the rotation of the system and the Earth.
Application Requirements
- Low bias drifts <3µg/min @ <3min after turn on
- Lightweight and compact
- High bias stability over various of environmental conditions
- Operating temperatures -40ºC to +85ºC
- Low power consumption
Applications
- North Finding
- Target location
- Tilt sensing
- Inertial Navigation