Platform Properties dialog box

The Platform Properties dialog box is used to enter the properties of a platform.

Note: Platform properties affect transducer geometry (among other things). If you do not have a clear understanding of transducer geometry it is recommended that you read the About transducer geometry page before changing any settings on this dialog box.

To display the Platform Properties dialog box:

  1. Display the Dataflow window (F7).

  2. Display a view showing the platform.

  3. Click the Platform icon, .

  4. Press F8
    -OR-
    Click Platform Properties on the Shortcut (right-click) menu
    -OR-
    Click Platform Properties on the Dataflow menu

General page

The General page is used to enter general information about the platform.

Settings

Description

Name

The name of the platform.

See also: Supported characters for names.

Notes

Additional information about the platform.

Position page

The Position page is used to enter the details that define the type and position of the platform.

Platform type

The Platform type box is used to specify the type of platform. You can select the following platform types:

Position

This section is only displayed if Position determined by GPS fixes is currently selected as the Platform type.

The Position source box is used to select the position variable from which the platform's position will be calculated. In addition, along-track display cruise tracks for acoustic variables that are linked to this platform will be based on the selected position variable.

Notes:

Location of the GPS antenna

This section is only displayed if Position determined by GPS fixes is currently selected as the Platform type.

The settings in this section are used to specify the location of the GPS antenna on the platform relative to a system reference point.

Settings

Description

X (alongship) (m)

The distance of the GPS antenna from the system reference point on the alongship axis (positive towards the bow, negative towards the stern). To simplify platform geometry calculations X(alongship) may be set to zero.

Y (athwartship) (m)

The distance of the GPS antenna from the system reference point on the athwartship axis (positive towards starboard, negative towards port). To simplify platform geometry calculations Y(alongship) may be set to zero.

Position of system reference point

The settings in this section are used to specify the geo-coordinates to map the platform system reference point to the earth.

Settings

Description

Latitude / Northing  (degrees / meters)

The latitude or northing of the platform system reference point on a fixed platform.

Notes:

  • Latitude can be entered in two ways. The first way is in decimal degrees, the second way is in degrees and minutes.

  • Northing is measured in meters to within 1 millimeter, and is positive. Each hemisphere has its own reference origin for northing determinations.

  • Mobile platforms take latitude and longitude from the specified Position source.

See About mapping and projections for more information.

Longitude  / Easting (degrees / meters)

The longitude or easting of the platform system reference point on a fixed platform.

Notes:

  • Longitude can be entered in two ways. The first way is in decimal degrees, the second way is in degrees and minutes.

  • Easting is measured in meters to within 1 millimeter, and is positive. Each zone has its own reference origin for easting determinations.

  • Mobile platforms take latitude and longitude from the specified Position source.

See About mapping and projections for more information.

Altitude (m)

The altitude (m) of the platform system reference point. Positive altitude is upwards.

Note: Pre-Echoview 6 EV files that recorded a value for Z(vertical) of the GPS antenna (for mobile platforms) will apply a depth to altitude transformation to the value. The transformed value is placed in Altitude (for the system reference point). Please review whether this Altitude value is suitable for your data.

Note: Acceptable settings for this dialog box depend upon the Map projection selected in Echoview (on the Mapping page of the EV File Properties dialog box).

Depth

Settings

Description

Z co-ordinate of the water level (m)

Z co-ordinate of the water level specifies the distance in meters of the water level with reference to the platform system reference point (positive downwards, negative upwards). The value of the Z co-ordinate of the water level represents the water level at the start time of the echogram data.

Heave source

Use the list to specify the Heave source line for the platform. For more information refer to About heave compensation.

Notes:

  • The Heave source can be an editable or raw line. A virtual line or sounder-detected bottom line cannot be used as a heave source directly. An editable line created from the line of interest can be used instead.
  • Use of a Heave source means that range based export analysis variables are assigned a special export value. For more information refer to About heave compensation: Notes.

Distance

This section is only displayed if Position determined by GPS fixes is currently selected as the Platform type.

The Distance source box is used to select the distance variable (e.g. vessel log) that will be associated with the platform. The selected variables will be associated with all acoustic variables that are linked to this platform and may:

Attitude page

The Attitude page is used to select attitude variables that are associated with a platform.

Setting

Description

Heading source

Is used to select the source of heading data. You can choose one of the following:

Setting

Description

Automatic

Automatically selects a heading variable if (and when) available, otherwise uses Heading from cruise track.

If a heading variable is selected automatically, this setting will no longer be available, the automatically selected heading variable will be displayed here as the Heading source.

Heading from cruise track

Derives heading data from the cruise track that is created from the position variable associated with the platform.

Fixed heading (north)

Available for fixed platforms.

Note: May be of benefit for fish track calculations.

Heading variable

Uses the specified heading variable (from a list of heading variables available in the EV file).

See: About heading data for further details.

Notes:

See also

About transducer geometry
Transducer geometry illustrated - Fixed platform example