15-minute is the time interval recommended as corrupted files (due to PC crash, power loss etc.).It is recommended to save the Log File to subdirectory within survey project.Select 1Hz for Output Rate of Groups 1, 102 & 104 These angles are best measured by Total Station or LIDAR unit. IMU Angular measurements, relative to the Vessel Reference Frame, should not be ignored. When using RTK or POSPac MMS IAPPK, lever arms should be measured to ± 0.005m.When using DGPS, lever arms should be measured to ☐.05m.The POS MV uses a right-hand Cartesian coordinate system, meaning:.Reference Point to Sonar Acoustic Centre (Survey Software).Reference Point to Primary GNSS Antenna (POS View).Reference Point to IMU Target (POS View).Port-Starboard: Normally ½ to ⅔ distance from transom to peak.)įor the easiest and most trouble-free mounting, only 3 measurements are needed (with Reference Point as the CoR). Important: The CoR is located at the intersection of Fore-Aft / Port-Stbd / Up-Down axes.This is despite the POS manual statement: “The reference point is defined as any convenient location on the survey vessel” Note that all POS MV lever arms should be measured from the CoR that is Designated as The Reference Point.Use of the CoR is critical for obtaining correct lever arm and mounting angles.Centre of Gravity (CoG) ≡ Centre of Rotation (CoR) Here, we consider the center of gravity equivalent to the center of rotation.Ensure the PPS Edge Setting in Sonic Control is “Rising” for a Positive PPS Pulse or “Falling” for a Negative PPS Pulse Set the pulse width to 1 millisecond at + or – 5 volts, with a gap of 1 second.Viewing the heave plot in POSView is a good way to confirm the actual heave period, aiding correct calibration.

Use 12 seconds in ocean swell, unless the period is longer.Use 9 seconds heave as a default setting.More detail on the required setup, settings and calibration is below.

Ensure that the installation is optimized by always using the recommended location for the POS reference point.

By going through the manual step-by-step, you lay the optimal foundation for good data collection

Ensure that the POS is installed correctly and the settings are as prescribed in Applanix and R2Sonic manuals.

Below are our top tips for perfecting your setup. However, it is simple to overcome these issues and others, by ensuring that your installation is correct and optimized. Many support requests from clients using the Applanix POS MV (either stand-alone or I2NS) have shared the common issue of motion artefacts.

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