Static Alignment vs Static Time

Static Alignment vs Static Time

Static alignment and static time are two concepts that are frequently confused. Many lidar systems cannot statically align their gyroscopes, but all lidar systems still benefit from time spent statically at the beginning and end of a data acquisition. 

Static Alignment 
Some high-end, fiberoptic-gyroscope IMUs can observe the earth rotate, and from this information they can align their gyroscopes with a direction motionlessly, so long as they have good GNSS data. With these systems, simply waiting statically for about 5 minutes will suffice as an alignment, and then you can begin your mapping mission. Most operators still perform a kinematic alignment, just in case the static alignment results in a poor heading. 

Static Period 
Only fiberoptic-gyroscope IMUs can determine their initial heading statically. It is true that all IMUs, and all INS systems, benefit from some static time at the beginning and end of a data acquisition. This static time is used to initialize biases associated with the IMU data. This static period should not be confused with a static alignment. 


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