needs financial support. It is your choice to
make a contribution to the ongoing project as
requested in the documentation.
Installing Charts
First, some sound advice from NOAA
regarding Raster Navigational Charts
(RNC)
4. Warnings (set forth in paragraph 4,
NOAA RNC Users agreement.)
Weekly updates to the RNCs are done on
a “best efforts” basis. The timing of their
availability is not guaranteed. You are
responsible for ensuring that your RNCs
are the most current edition and that the
most recent updates have been applied.
NOAA RNCs™ were made by scanning
the NOAA paper chart printing materials.
Any inaccuracies due to old methods
of collecting, processing and displaying
data on the paper chart were transferred
to the RNCs. As a result, the accuracy
of modern positioning systems such as
GPS may exceed the positional accuracy
of the RNC. The impact of positioning
accuracies can be minimized by not
zooming an RNC beyond the scale of
the original NOAA chart.
While NOAA has accuracy standards for
each step in the data collection and chart
production process, much of the depth
information found on NOAA charts is
based on surveys conducted before 1940,
the shoreline is more than 20 years old,
and paper charts used to be compiled
manually.
OpenCPN does not come with any
pre-installed charts. It is up to the user to
find and install charts. To install charts,
OpenCPN must be pointed to a directory
containing charts in one of the recognized
chart formats. Do not point OpenCPN
to an individual chart. You must specify
the directory that contains the charts. For
this course, you will download free NOAA
raster navigational charts (RNC) for your
state, and keep them in a folder named
Charts or BSBChart on your Desktop in My
Documents, or on the “C” drive. To create
a chart folder on your Desktop, right click
on Desktop and select “New” and then
“Folder.” By right clicking on the file and
selecting “rename” you can type in either of
the suggested names, Charts or BSBChart,
the format used by NOAA.
To download the charts, type in www.
charts.noaa.gov/RNCs/RNCs.shtml then in
the “RNCs by State” matrix, click on your
state to download all the charts for that state
including the large scale area chart. Then
click on “save” and choose your “Desktop
Charts” or “Desktop BSBChart” for saving
this file. If using Windows 7, the file may
be in the “downloads” folder in “My Documents,”
or in the bottom left corner of the
“Chart Downloader” page. If so, you can
hold the mouse button down and drag the
file to the “Charts” or “BSBChart” folder
on your desktop. Double click the folder
on the Desktop to open it. Double click
on the zip-file that you downloaded. Select
“Extract all files” and keep the name of the
target folder the same. After extracting you
can close the various open files. To confirm
that the file is unzipped, double click your
Charts or BSBChart folder. Both the zipped
and unzipped files should appear; you may
delete the zipped file to conserve storage
space.
Launch OpenCPN and then open the
Options Dialog in the Toolbar by clicking
the “wrench” located along the top
left side of the screen. In DISPLAY, under
the GENERAL tab, select and left click the
box “Show Chart Outlines.” This will help
you visualize the loaded charts. Under the
ADVANCED tab, you may want to click
on the box “Enable Chart Quilting” at this
time so your charts will meld together.
Without “Chart Quilting” your charts will
look like single pages in a book ripped out
and laid side-by-side instead of seamlessly
joined together.
Now click on the tab “Charts” and
Section 18: Charts 219
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/RNCs.shtml