About ping modes

With the advent of multibeam and scanning sonars, various new shapes of ping have been introduced which affect the spatial relationship between pings and their environment. To properly treat the various types of ping, Echoview associates with each ping in an acoustic variable one of the following modes:
 

Ping mode

Description

Notes

1

Standard single-beam.

Generally modeled by a line in space following the beam axis. Split beam echosounders which can resolve position of single targets within a beam are treated specially in the 3D Single Targets graph. See also About beam geometry.

2

Standard multibeam.

Modeled by a flat sector in space (the shape of a fan). Pings of this mode can be positioned in space using transducer geometry. Rotation in the plane of the beam (Roll correction) and variable (non-uniform) beam width is supported.

3

H-mode.

Modeled by the shell of a cone in space. All data points must lie on the surface of this cone. The cone angle is measured by tilt which is permitted to change from ping to ping.

The cone is assumed to be vertically oriented with the apex at top. Warning: Variables of this ping mode assume but do not enforce a zero elevation. Applying an elevation may not have the desired consequences. See About transducer geometry for a discussion of elevation.

Mnemonic: H for Horizontal - with low tilt angles in mind, and the notion of scanning near the surface in a long range circle from the vessel. It is also possible to scan an entire volume of water by varying tilt from 0 to 90 degrees, however.

Notes:

  1. The H-mode cone is considered to have a leading and trailing face. The leading face consists of those beams which are pointing forwards (relative to the vessel) and the trailing face consists of those beams which are pointing backwards (relative to the vessel). A beam pointing port is in the leading face and a beam pointing starboard is included in the trailing face. See 3D school detection algorithm and About integration algorithms.

  2. Echoview requires that any variable containing H-mode pings be associated with a transducer that has elevation, azimuth and rotation set to zero. If you attempt to display a variable which does not meet this requirement a warning will be displayed. You can modify the orientation of an existing transducer on the Orientation page of the Transducer properties dialog box, or create a new transducer on the Dataflow window and associate it with a variable on the Calibration page of the Variable Properties dialog box.

  3. Tilt angles from -10° to 89° are supported in Echoview.

4

V-mode.

Modeled by a flat sector in space (as with ping mode 2) with an additional support of bearing which is permitted to change from ping to ping.

The sector is assumed to be vertically oriented with the apex at top. Warning: Variables of this ping mode assume but do not enforce a zero elevation. Applying an elevation may not have the desired consequences. See About transducer geometry for a discussion of elevation.

Mnemonic: V for Vertical - with a sweeping scan in mind, altering bearing to scan a volume of water. It is possible to sweep a full circle and thus scan once an entire volume of water beneath the transducer.

Notes:

  1. Echoview requires that any variable containing V-mode pings be associated with a transducer that has elevation, azimuth and rotation set to zero. If you attempt to display a variable which does not meet this requirement a warning will be displayed. You can modify the orientation of an existing transducer on the Orientation page of the Transducer properties dialog box, or create a new transducer on the Dataflow window and associate it with a variable on the Calibration page of the Variable Properties dialog box.

  2. Bearing angles from 0° to 359° are supported in Echoview.

5

S-Mode.

Modeled by a flat sector in space (as with ping mode 2) with an additionally support of tilt and bearing which are permitted to change from ping to ping.

Warning: Variables of this ping mode assume but do not enforce a zero elevation. Applying an elevation may not have the desired consequences. See About transducer geometry for a discussion of elevation.

Mnemonic: S for Slant - supporting variations in both tilt and/or bearing.

Notes:

  1. Echoview requires that any variable containing S-mode pings be associated with a transducer that has elevation, azimuth and rotation set to zero. If you attempt to display a variable which does not meet this requirement a warning will be displayed. You can modify the orientation of an existing transducer on the Orientation page of the Transducer properties dialog box, or create a new transducer on the Dataflow window and associate it with a variable on the Calibration page of the Variable Properties dialog box.

  2. Tilt angles from -10° to 89° are supported in Echoview.

  3. Bearing angles from 0° to 359° are supported in Echoview.

See also

About beam geometry
About transducer geometry

About depth, range and altitude