Time Constants - JRC PRONAV V200S User Manual

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Time Constants

The V200s incorporates user-configurable time constants that can
Overview
provide a degree of smoothing to the heading, pitch, Rate-of-Turn (ROT),
Course-over-Ground (COG), and speed measurements.
You can adjust these parameters depending on the expected dynamics of
the vessel. For example, increasing the time is reasonable if the vessel is
very large and is not able to turn quickly or would not pitch quickly. The
resulting values would have reduced "noise," resulting in consistent
values with time.
If the vessel is quick and nimble, increasing this value can create a lag in
measurements.
If you are unsure on how to set this value, it is best to be conservative
and leave it at the default setting.
Note: For heading and rate of turn there is no lag once the sensor is
calibrated and enabled.
Formulas for determining the level of smoothing are located in the
Hemisphere GNSS Technical Reference
set this value, it is best to be conservative and leave the default setting.
Use the $JATT,HTAU command to adjust the level of responsiveness of
Heading
the true heading measurement provided in the $GPHDT message. The
default value of this constant is 0.2 seconds of smoothing when gyro-aid
is enabled.
By disabling gyro-aid, the equivalent default value of the heading time
constant should be 0.5 seconds of smoothing. This is not automatic, and
therefore it must be manually entered.
Note: Increasing the time constant increases the level of heading
smoothing and increases lag (with gyro-aid disabled).
Rev.1
10.02.2020
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Manual. If you are unsure how to
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