1.3. Importing Track Data
1.3.1. Introduction to Replay files
Debrief reads text files using a format named the Replay file format (Replay was an application used in Debrief-style tasks in Royal Navy analysis in past years).
Replay files are ASCII-FILES containing vessel position data in a flat-file format similar to that below:
Example 1-1. Sample Replay file contents
951212 050000.000 CARPET @C 12 11 10.63 N 11 41 52.37 W 269.7 2.0 0 951212 050100.000 CARPET @C 12 11 10.58 N 11 42 2.98 W 269.7 2.0 0 ;NARRATIVE: 951212 095700.000 TOMATO SUSPECTED DETECTION OF RED 951212 050200.000 CARPET @C 12 11 10.51 N 11 42 14.81 W 269.9 2.0 0 951212 050300.000 CARPET @C 12 11 10.51 N 11 42 27.27 W 268.7 2.0 0 951212 050400.000 CARPET @C 12 11 10.28 N 11 42 40.33 W 270.6 2.0 0
This data has a single vessel location per-line, with white-space separated columns containing this data:
Date (year, month, day)
Time (hours, minutes, seconds, decimal seconds))
Vessel Name (single-word))
Formatting to apply (see the maintainer documentation for details of this, but experiment with the second character to change the default colour of the track).)
Latitude (deg, min, sec, hemisphere))
Longitude (deg, min, sec, hemisphere))
Course (degrees))
Speed (knots))
Depth (m))
Note the third line, which contains a narrative entry. This entry represents one of a group of types of data called Annotation Entries. These entries allow inclusion of data other than vessel locations, and can be interspersed with positional data throughout the file.
Multiple vessel tracks can be contained sequentially in a single Replay file.
For more detail regarding this file format, including how to represent annotations which are only visible for a defined time period, together with lines, ellipses and rectangles, examine the maintainers section of the this document.
1.3.2. Import
You must now import some data into Debrief, so click on the Import Data button (it's on the File toolbar), which looks like this:
1.3.3. File Open
A file-open dialog will now open, containing a filter to only show Replay files. Navigate to the demonstration files (boat1.rep & boat2.rep) which should be stored in the installation directory (which on Windows is normally in C:\Program Files\Debrief 2002).
The File-Open dialog is more complex than others you may be familiar with. The left-hand side works as expected, showing the list of files and directories in the current directory. Change directory using the drop-down list at the top of the dialog. When you single-click on a REP or XML file (the file types accepted by Debrief), the contents of the file appear in the Navigation window on the right-hand side. The drop-down list at the top of the Navigation window (labelled C:\D3 in this example) provides a list of the directories most recently accessed by Debrief.
Behind the Navigation window is the Find Files window. This collection of forms allow you to search for files by name, date or contents.
1.3.4. Select files
Back to the tutorial, navigate to the directory where Debrief was installed, then select both BOAT1.REP and BOAT2.REP files using the Control key, then press .
A progress bar will flash up to illustrate the import process. On completion, the track data will appear in the plot area on the right-hand side of the screen.
You will see that the Red track, named CARPET is plotted in several different colours. This is an illustration of per-position colouring for tracks. The colours can be specified inside the REP file, as we see here, or can be specified within Debrief using the Track/Time toolbox, Section 3.6.5 under Reformat Positions
1.3.5. Default labels
When data is imported, Debrief applies default values to the time labels for positions. The first point in a track, together with the first point every day includes the day, otherwise just hours and minutes are displayed.
Of course though, you haven't learnt how to show the labels, so that's still to follow - but remember, when you switch on the labels for a track, it was at the import stage that the default labels were set.