Most of the sensors on a vessel (such as gyros, transducers, etc.) record the time in their data using their own internal clocks. If a clock is not using the correct time, its data will not be synchronized with the data from the other sensors. In this case, you must correct the sensor’s time records by adjusting the Time Correction field in its Attribute window.
The Time Correction field represents how much faster the sensor clock is (in seconds) than the correct time. Therefore, the Time Correction must be positive if the sensor clock is ahead of the correct time (fast), or negative if the sensor clock is behind the correct time (slow).
When HIPS needs to convert the time recorded by a sensor to the correct time, it subtracts its Time Correction from its recorded time:
Correct time = Recorded time - Time correction
Equivalently, when HIPS needs to read the data that a sensor recorded at a certain time, it adds its Time Correction to the correct time and searches for the result in the times recorded in the sensor data:
Recorded time = Correct time + Time correction
For example, if a sensor has a Time Correction of +2 seconds and HIPS needs to read data recorded at the correct time of T10:30:45, HIPS will search the sensor data for records marked with the time T10:30:47.