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:

Display the Dataflow window (F7).
Display a view showing the platform.
Click the Platform icon, .
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 determined by GPS for a mobile platform (for example, a boat), or
Fixed for a non-mobile platform.

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, alongtrack display cruise tracks for acoustic variables that are linked to this platform will be based on the selected position variable.

Note: Position source can default to a raw position variable or a virtual position variable. In some cases the position variable is one that was most recently used. For new EV files, the first single source GPS variable is assigned. When a single source GPS variable is unavailable, a combined GPS source is used. Prior to Echoview 12, the default value was the combined GPS variable. In some cases, a combined GPS variable with duplicate fixes can be problematic.

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 fixed 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 coordinate of the water level (m)

Z coordinate 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 coordinate 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 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. Virtual lines can be used under certain conditions.
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.

Water current

Under a fixed platform, a Water current speed source can be specified. Source data are water speed CSV values. See also About speed data.

Distance

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

The Vessel log distance source list 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:

be used as the source of distance for time/distance grids,
be used as the source of distance for school detection, and
be included in exported data, see About analysis variables.

Transect

Settings

Description

Transect group source

Assigns a transect group to the platform.

Note that Echoview (onscreen and export) analyses are constrained to the part(s) of an analysis domain overlapping with the transects in an assigned transect group.

For more information refer to About transects, Using transect groups and Transects and analyses.

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:

Roll can be corrected for in Echoview, but this is not applied to the platform. It is applied to variables directly and makes specific limiting assumptions. See About roll data for further information.
Pitch can be corrected for in Echoview, but this is not applied to the platform. It is applied to variables directly and makes specific limiting assumptions. See About pitch data for further information.