Dynamic calibration for multi-beam bathymetric system based on characteristic data processing
The geometric installation error of the multi-beam bathymetric system will affect measure accuracy of the depth and location, which must be faced and resolved in the engineering survey urgently. The most important three kinds of the installation error are roll error, pitch error and yaw error. Through quantitative analysis of impact of installation error to the measure result, a dynamic calibration method has been proposed in the paper. In the method, installation errors can be obtained by analyzing bathymetric result from the characteristic terrain seafloor and the errors will be used as the parameters to calibrate other bathymetric result. Validity of the method has been proved by processing the measure data from Songhua Lake test.
EM1002 Multi-beam Sounding System and its Parameter Correcting
The multi-beam sounding system is used for swath surveying,which can survey sea bottom with total coverage and no missing out .The system has the advantage of the high accuracy,high efficiency,high quantity,etc.This paper summarizes the technique and function of EM1002 multi-beam sounding system and describes in detail the internal parameter correction by using calibrate multi-parameter correcting software.
Field Calibration Procedures for Multibeam Sonar Systems
Abstract : Multibeam sonar systems are the latest advancement in hydrographic surveying technology. These systems consist of a transducer, motion sensor, gyrocompass, and navigation system. Reliable data can only be acquired after proper calibration has been performed on the system as a whole. This calibration begins with the alignment and static offsets of the sensors referenced to the centerline of the vessel and the transducer. The alignment will reduce the static corrections of each sensor and can be performed with either GPS receivers or a total station geodetic instrument. After the static offsets are determined, a patch test is performed. This test is designed to reveal the following residual biases: (1) pitch offset, (2) roll offset, (3) positioning time delay, and (4) azimuthal offset. The test consists of a small survey of several lines that are evaluated for inconsistencies and then corrected using software designed for multibeam surveys. There are several mathematical equations developed for analyzing these biases that are incorporated into the processing software for the patch test. The performance test is the final check of the offsets and biases to verify whether the data meet accuracy requirements for the survey. This test is a series of parallel and cross lines with significant overlap to give redundant data.