2.3. Adding chart features
2.3.1. Chart features toolbar
Debrief also allows you to add items to the plot.
These items are contained in two toolbars; Chart Features and Drawing. In Debrief, hover the mouse over them to see what type of item they create.
 | It is important to note that each time you click on an item from the toolbar, a new instance of it is created, it does not re-open an existing item. |
Back to the palette items, experiment with the buttons by putting new features on the plot.
2.3.2. Scale
The Scale button provides a scale, indicating to the viewer the current area of coverage of the plot. Once created the scale values can be set automatically or manually, as described below:
2.3.3. Grid
Next, try with a new grid:
A properties panel will open, in this panel change the Delta (the space between the lines) to 5 (minutes), and make it visible. Now Apply. The grid will now appear on the plot.
Note the option provided to allow you to select to plot labels on the grid lines. Decimal seconds will be displayed when the delta requested is less than one second.
2.3.4. Coastline
The Debrief installation includes a low-resolution coastline datafile. Whilst it does cover the whole globe, it does so at a low resolution, so is only useful for an overview. The vectored chart data discussed later provides a much lower resolution of data.
Have a go at adding a Coastline, although you may need to zoom out to see it (Debrief veterans will be please to see the tracks no longer appear over desert). The screenshot shows the British coastline, which you can view by zooming out and panning upwards from the sample tracks.
2.3.5. Vectored data
The addition of vectored chart data is covered later in this document, in Viewing VPF data The image below provides a sample of the level of detail supplied.
2.3.6. ETOPO gridded bathy
Whilst the VPF dataset provides a contoured bathymetry within broad depth steps, the ETOPO dataset provides a gridded bathymetry in 5' steps. The image below provides a sample of the level of detail supplied.
 | The 'ETOPO-5' data set is originally from the U.S. National Geophysical Data Center (NGDC) in Boulder, Colorado (USA), and represents the "best" available digital terrain values as integrated from existing five and ten-minute digital sources. The data set has elevation values spaced at every five-minute latitude/longitude crossing on the global grid (approx. nine km.-sq. spatial resolution, or 12 x 12 pixels/degree), and a one-meter contour interval. Bathymetric values are included in this data set, starting at approximately 10,000 meters below sea level, while the elevation values extend up to heights of approximately 8,000 meters above sea level. Some original sources of the data used include the U. S. Defense Mapping Agency for the conterminous USA, Japan and Western Europe; the Australian Bureau of Mineral Resources, and the New Zealand Department of Scientific and Industrial Research. GRID has reformatted the original NGDC data file to place the origin at 180 degrees West longitude, instead of at 0 degrees Greenwich Meridian. The 'ETOPO-5' data file has 2160 records of data with a length of 8640 bytes each: the size of the data array is 2160 lines by 4320 elements, but this is a l6-bit or two bytes per element data file. The origin of the data file is at 90 degrees North latitude and 180 West longitude, and it extends to 90 degrees South latitude and 180 degrees East longitude. The data file comprises 18.66 Megabytes. The version of this data file at GRID has been discovered to contain two records (lines) of flawed data values; that is, portions of lines 2055 and 2056, beginning at the Weddell Sea north of Antarctica and continuing eastward. GRID is currently waiting for a response from the data supplier (NGDC) before attempting any replacement of what appear to be anomalous data values. There are two useful references for the 'ETOPO-5' data set. These are: "Edwards, Margaret Helen, 1986. Digital Image Processing of Local and Global Bathymetric Data. Master's Thesis. Department of Earth and Planetary Sciences, Washington Univ., St. Louis, Missouri, USA, 106 p." and "Haxby, W. F. et al., 1983. Digital Images of Combined Oceanic and Continental Data Sets and their Use in Tectonic Studies. EOS Trans- actions of the American Physical Union, vol. 64, no. 52, pp. 995-1004." |
The following options are provided for plotting ETOPO data:
 | The ETOPO dataset uses a significant amount of memory on your PC, typically 30Mb, though this only gets loaded once per Debrief session, however many plots are loaded. Writing a WMF file with ETOPO data visible requires even more memory, and can cause Debrief to hang or crash. This problem can be overcome by following the advice described in Starting Debrief |