More on CW Activity

I have generalised the code to plot the CW Activity Metric in the relevant github repository so that it can generate plots of data in bins that are less than a year in duration. For example:

This allows one to see the peaks corresponding to the CQ WW and ARRL DX contests each year, as well as the annual cycles of activity as propagation changes through the year. (And the change in behaviour in 2020, in which the early months of the year saw increased activity, corresponding -- one assumes -- to widespread stay-at-home lockdowns because of the COVID-19 pandemic, followed by a decrease as restrictions were eased over the following months.)

Of course, it's trivial to filter the RBN data before generating the CW metric. So, for example, we can create plots of annual data by continent (ignoring AN, for which there are too few data for meaningful analysis). The graphs are presented without further comment, as I think that they generally speak for themselves:

We can repeat this process, but binning the data into twelve bins of equal duration each year:

Code for Plotting CW Activity

In prior posts (here and here) I describe a CW activity metric derived from the RBN, and plot the value of that metric on an annual basis. I thought that it might be useful to share the code that I used; although the earlier of the posts above describes the algorithm, the posts do not include any code.

Accordingly, I have added the code to a github repository. The new code is in the cw-activity directory.

Although it would have been much more efficient to code a monolithic program in C++, in the interests of making things more portable I used only scripts that should run on a wide range of machines. The only fundamental change needed to run the scripts on other machines is probably to change the variable FILENAME in the rbncat script. That variable should point to a mounted copy of the RBN database, as may be generated by the other tools in that github repository. Note that byte offsets are hard-coded into rbncat, so you should check that that script works as expected on your system before attempting to generate the activity plots. You might need to change the values of the byte offsets if, for example, for some reason you are using a line separator in your copy of the RBN database that is more than one character in length.

Minor change to Reverse Beacon Network data files

While working on a script to process the RBN data files last week, I discovered that the raw historical data maintained by the RBN itself have not been properly filtered to remove duplicated lines. I have therefore replaced the data files I use with new versions in which the duplicated lines have been removed. This is a minor change (on a recent day, there were a total of 1,194,001,674 lines in the database, 1,188,655,665 of these were unique, implying that 5,346,009 additional lines were present, for a duplication rate of about 0.5%).

Estimating CW Activity from RBN data, 2009 to 2020

It is possible to generate a metric of CW activity from RBN data. Extending the analysis in the linked post to 2020, we first check that the data have not changed in a way that would vitiate the result:

As in prior years, the overall shape of the data seems to be robust.

So, extending the prior analysis to include 2020, we obtain this graph:

Unsurprisingly, we see that a marked increase in CW activity (as measured by the defined metric) occurred in 2020. Because activity on all HF bands seems to have increased, it seems fair to ascribe the overall increase substantially to the COVID-19 pandemic rather than merely the improvement in propagation above 14 MHz that characterised the last quarter of 2020. It will be interesting to see if this increase is sustained in 2021.

Perhaps the most important result from this exercise, though, is the continued lack of evidence of any substantive long-term decline in the number of calls active on CW.