WALDO

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Python tools

A set of useful tools has been curated into a python library, made publicly available at this site, with thanks to David Richardson for producing and documenting these tools.

Sample Matlab scripts

We provide a set of Matlab scripts for the purpose of quickly plotting/analyzing large amounts of data for easy viewing. These items are provided as is, and the hope is that you may find any one of them useful enough, and you can use it as a base to build your own data analysis tools. If you do not have access to Matlab, there is a free open-source program can Octave with replicates many of its functions.

Please also note that the detailed format of the data is described in the “format” page, and reading in the data is very simple and can be done in other languages, too.

To get started, move all the files in the package to the work directory underneath the Matlab folder. From Matlab, you can run one of scripts for data analysis, by simply typing its name into Matlab (the other files in the package are just supporting scripts for the five main ones):

vlf_spec: Used to make a plot and spectrogram of a single segment of time, 30 seconds or less in length.

narrowqplot – intended to make a single amplitude/phase plot from a single pair of amplitude/phase data files

makespectrograms: Used to take a longer file of data and create a bunch of two-channel spectrograms of each piece of the data, and saving each spectrogram to a jpeg

makenarrowplots: Used to take a long narrowband file and create a bunch of plots of each piece of the data, and saving each plot to a jpeg.

soundiscool: Used to create a .wav sound file from a piece of broadband data

MapMaker: Used to visualize locations of VLF transmitters, receivers, and great circle paths

matGetVariable.m: Lower-level scrips used to extract a selected variable from a data file. See the “Format” page for details on its usage and the variables available in each file. You also need the matReadHeader.m file to use it.