Calculating the angles from Complex data for Beam Type: 17 49, 65 and 81
The split-beam angles, angles for short, can be calculated based on the output angle information included in the Sample binary
datagram. Use the beam type of the transducer and the type of angle information in the datagram (Complex or Angle) to determine the right processing of the angle data
Transducers having three sectors
This section describes the steps involved in calculating the angles for the WBT having three sectors. This transducer and transducers having the same geometry and sectors will follow the same steps in calculating the angles.The angle data in the Sample binary datagram is Complex. The parameter Beam Type will identify the transducer geometry and type. The Beam Type for this transducer is provided in the raw file.
| • | Beam Type:17 |
This transducer and transducers having the same geometry and sectors will follow the same steps in calculating the angles.
Start by defining the three complex channels from the transducer. In this case the transducer is a WBT.
The following calculations and equations apply when the BeamType is “17”.
The angles of the split beam, Ux and Uy, are calculated using the following equation.
| • | Ux is the along ships angle. |
| • | Uy is the athwart ships angle. |
| • | Λ is the Angle Sensitivity. This information is normally given in the data sheet for the product. |
The calculated angles are EK INT format. The angles can be converted from EK INT format to Mechanical Angle Format.
The arctan2 is expanded for giving results in the following range: <-Π, Π].
Note
Use the section Implementation of arctan for implementation details.
Use the section Specal scaling requirements for split beam transducers to scale the angles appropriately.
Transducers having three sectors and a centre element
This section describes the steps involved in calculating the angles for the WBT having three sectors and a centre element. The angle data in the Sample binary datagram is Complex. The parameter Beam Type will identify the transducer geometry and type. The Beam Type for this transducer is provided in the raw file.
| • | Beam Type:49, 65, 81 |
This transducer and transducers having the same geometry and sectors will follow the same steps in calculating the angles.
The relationship between the beams, orientation of the beams and numbering of the complex number in the Sample binary datagram
is given by the following:
The angles of the split beam, Ux and Uy, are calculated using the following equation.
| • | Ux is the along ships angle. |
| • | Uy is the athwart ships angle. |
| • | Λ is the Angle Sensitivity. This information is normally given in the data sheet for the product. The angle sensitivity is retrieved from the Configuration XML datagram. |
The calculated angles are mechanical angles.
The arctan2 is expanded for giving results in the following range: <-Π, Π].
Note
Use the section Implementation of arctan for implementation details.
Use the section Specal scaling requirements for split beam transducers to scale the angles appropriately.