Getting Started with Seabird

Inside python

>>> import seabird

In a python script, one can use like this:

>>> from seabird.cnv import fCNV
>>> profile = fCNV('your_file.cnv')
>>> profile.attributes  # It will return the header, as a dictionary.
>>> profile.keys() # It will list the available variables.
>>> profile['TEMP2'] # If TEMP2 was on the .keys(), this is how you get the data. It will be a masked array.

The data from a profile is hence treated as it was a dictionary of Masked Arrays. To plot it, one could:

>>> import matplotlib.pyplot as plt
>>> plt.plot(profile['depth'], profile['TEMP'], '.')
>>> plt.show()

From the terminal

One way to use is running on the shell the cnvdump. Independent of the historical version of the cnv file, it will return a default structure:

seabird cnvdump your_file.cnv

That can be used in a regular shell script. For example, let’s consider a directory cruise1 with several sub directories, one for each leg of the cruise. One could list all the latitudes of each CTD cast like:

for file in `find ./cruise1 -iname '*.cnv'`
do seabird cnvdump $file | grep latitude
done

Now let’s get that list ordered by the latitude:

for file in `find ./cruise1 -iname '*.cnv'`
do
    echo -n  `seabird cnvdump $file | grep latitude`
    echo -n " "
    echo $file
done | sort -n > mylist.txt

To convert a .cnv to a standard NetCDF, run:

seabird cnv2nc your_file.cnv

More examples

I keep a notebooks collection of practical examples handling CTD data . If you have any suggestion, please let me know.