About Cruise Tracks

A cruise track is a graphic representation of the geographic position data in a position variable, optionally combined with the data in an acoustic variable. There are three types of cruise track in Echoview:

See also:

GPS fixes

GPS fixes cruise tracks are created from position variables and provide information on the status of the GPS data.

To display a GPS fixes cruise track, do one of the following:

Cruise track window features

GPS fixes are displayed in the following way:

Notes

GPS fixes are joined by a continuous line to form the cruise track. The first, last, and all good fixes are used.

The color of each line segment shows the status of interpolated positions:

Green

indicates the position status

good

Magenta

indicates the position status

uncertain

Notes:

See also

Using cruise tracks
Processing and smoothing cruise tracks

Adding map and Waypoint files to cruise tracks windows

Cruise track keyboard shortcuts

Processing GPS data

Bottom classification display

A bottom classification produces a bottom points variable that contains geographic and bottom points data. The bottom points cruise track may be used to display bottom point class in alongtrack or point style. The bottom points cruise track can be auto-synchronized with a bottom points table, bottom points integram, echograms and Media window. From more information refer to About bottom classification.

To display a bottom points cruise track, do one of the following:

Along-track display

Along-track display is a color-coded cruise track showing integration or other processing results derived from an acoustic variable. For example, it is possible to create a cruise track showing the depth of the sea floor, or the mean Sv value, as seen below. Along-track displays can only be created from raw or virtual variables with a data type of Sv. For instructions, refer to Using cruise tacks: Displaying an along-track display cruise track.

To display an Along-track display, do one of the following:

Analysis results that can be output to an along-track display are:

To select analysis results for output to an along-track display, see Using cruise tracks: Along track display.

Each segment on the cruise track shows the mean value of the selected analysis variable calculated across a range of pings. The range of pings for each segment is determined by the time/distance grid settings in the Variable Properties dialog box and can be based on time, distance, or number of pings. In the above example, each segment in the cruise track shows the mean Sv for every 20 pings of data.

Notes:

3D cruise tracks

3D cruise tracks are a 3D object which can be added to scenes.

The 3D cruise track plots the position of the GPS antenna. See About transducer geometry for further information about how the position of the GPS antenna is specified.

See Displaying a 3D cruise track and Using a 3D cruise track for scene animation for further information.

Cruise track display controls

Scale bar

To display a scale bar for the cruise track window, select Show scale bar on the Cruisetrack Display page of the Variable properties dialog box. The scale bar shows nautical miles (nmi) and kilometers/meters (km or m).

Note: This is not available on 3D cruise tracks.

Grid lines

To display a gird lines for the cruise track window, select Show grid lines on the Cruisetrack Display page of the Variable properties dialog box. Grid line labels are affected by the Map Projection on Mapping page of the EV File Properties dialog box.

Zoom controls

To display a Zoom controls for the cruise track window, select Show zoom controls on the Cruisetrack Display page of the Variable properties dialog box.

Note: This is not available on 3D cruise tracks.

What is plotted where?

To summarize what is plotted where, each of the three types of cruise track plots the course of a slightly different point in the echosounding system as follows:

         GPS fix cruise tracks       position of the GPS antenna
  along track display cruise tracks   position of the transducer
  3D cruise tracks   position of the GPS antenna

See About transducer geometry for more information on how these three positions interrelate.

Define and integrate a region

Regions may be created and displayed in cruise track and along track windows. Displayed regions may also be integrated. These features allow you to asses your data at a macro-level and in geographic context.

The Vertical band tool enables you to make a selection on a cruise track which extends the entire depth of the echogram at a defined time/GPS position. The selection is displayed as a region which follows the cruise track and starts at the nearest good GPS fix to the mouse pointer and ends at the nearest good GPS fix to the mouse pointer. To define a region, on the Shortcut menu select Define Region. The assigned region type and class default to those last used. Further changes can be made using the Region browser.

See Using cruise tracks - Define and integrate a region for more information.

Notes:

See also

Using cruise tracks
Processing and smoothing cruise tracks

Adding map and Waypoint files to cruise tracks windows

Cruise track keyboard shortcuts

About color schemes

About setting variable properties

Export positions

Echoview Status bar