As in the past I note that a reasonable

*a priori*case can be made on the basis of propagation characteristics that somewhat different metrics in the G(Δ, n) series might be better representations of RBN coverage on some of the bands. However, rather than make this into a full-scale research project, I shall here simply continue to use the G(15, 100) metric on the basis that it seems "good enough" on all bands.

#### RBN Posting Stations as a Function of Time

We begin by looking simply at how the number of per-band posters to the RBN has varied since the RBN's inception. (NB Throughout this post, we ignore posters for which the location is not recorded by the RBN; plots for which the abscissa is time show one datum per month.)

First, a plot of the total number of posters as a function of time:

This can be more compactly represented, along with similar per-band data for 160m through 10m (excluding 60m):

Turning now to the geographical distribution of the posting stations, we can display the mensal values of G(15, 100) in a similar manner:

These figures seem to make rather clearly the rather depressing point that since early 2017 there has been no substantive or sustained increase in either the number or geographical distribution of the stations posting to the RBN.

Finally, we can combine the mensal values of G(15, 100) and the number of posters. Firstly, including all bands:

The summary plot for these data is slightly different, as the ordinate is multi-valued for some values of the abscissa. So, in this summary plot, we take the mean value of G(15, 100) in bins of width equivalent to ten posters, and plot rectangles in the equivalent colours:

All in all, a rather unhappy picture emerges, in which the RBN, after expanding and increasing coverage rather nicely for the better part of a decade, became essentially static in early 2017 and has effectively failed to expand numerically or in geographical coverage since then.

#### G(15, 100) as a Function of Time

Turning now to the geographical distribution of the posting stations, we can display the mensal values of G(15, 100) in a similar manner:

These figures seem to make rather clearly the rather depressing point that since early 2017 there has been no substantive or sustained increase in either the number or geographical distribution of the stations posting to the RBN.

#### G(15, 100) as a Function of the Number of Posters

Finally, we can combine the mensal values of G(15, 100) and the number of posters. Firstly, including all bands:

The summary plot for these data is slightly different, as the ordinate is multi-valued for some values of the abscissa. So, in this summary plot, we take the mean value of G(15, 100) in bins of width equivalent to ten posters, and plot rectangles in the equivalent colours:

All in all, a rather unhappy picture emerges, in which the RBN, after expanding and increasing coverage rather nicely for the better part of a decade, became essentially static in early 2017 and has effectively failed to expand numerically or in geographical coverage since then.

## No comments:

## Post a Comment

Note: Only a member of this blog may post a comment.