SPAN® Heave

The rise and fall movement of a boat or ship tends to corrupt returning sonar data in marine mapping applications, leading to errors in depth measurement. Select SPAN receivers feature our cost-effective, robust, real-time heave output option that compensates for this vertical movement of the boat, regardless of vessel dynamics. By eliminating vessel movement, sonar technology can generate a much clearer, coherent image of the ocean floor:

Highlights:

• Dynamic alignment with rapid solution convergence (<1 min after inertial alignment)
• Provides real-time change in height to compensate wave effects
• IMU options vary in price range, export control and size
• Real-time and post-processing options available
• Configurable Heave filter window (based on time frame/length of monitor wave motion)
• Inertial Explorer offer post-processed heave output

Real-Time and Post-Processing Options

Real-Time Measurements: SPAN receivers provide accurate, real-time measurement of wave motion under the most difficult marine conditions and vessel dynamics. They offer a full six degrees-of-freedom position and orientation, measuring position, velocity and attitude. The heave filter is an asynchronous log available at 10 Hz.

Post-Processed Solution: Waypoint® Inertial Explorer® software from NovAtel post-processes data forward and backward, ensuring the most accurate heave solution.

SPAN Heave Accuracy

Real-Time Measurements: SPAN Heave 5 cm or 5%

Post-Processed Solution: Waypoint® Inertial Explorer® heave 3.5 cm or 3.5%

Note: NovAtel's accuracy specifications are groud mobile derived. For specific application performance results, contact NovAtel.

For System level accuracy please see NovAtel SPAN brochure or the Specific IMU data sheet for performance specifications.
http://www.novatel.com/products/span-gnss-inertial-systems/

How it Works:

The SPAN Heave algorithm estimates the short term, vertical displacement of a vessel, relative to the mean sea state caused by waves or swells. This allows a sonar system to compensate for the range errors caused by these effects.