[Talk-ca] Amateur Radio Maps...

[Colin McGregor]

Last Saturday I was at a party co-hosted by Richard Weait (thanks),
where the topic of maps for amateur radio use came up.

A topic that has been of interest to me is amateur radio and disaster response.

So, I am looking for software that will generate two maps from Open
Street Map data:

- An azimuthal equidistant projection map for any arbitrary latitude / longitude
- A day and night map (ie: what parts of the world are CURRENTLY in
sunshine / darkness)

So, what makes the requirement for the above a little tough?  I want
the software to be under the GPL (or some other open license) so it
can be redistributed without issue. I want it for Linux (so the OS to
support the application can also be redistributed without issue). I
want the application to run stand-alone (so if there is a problem with
the internet connection I don't want the application to suddenly
become useless). The data for this can not be more than a few MB at
most (but then this shouldn't be an issue, given that road, rail, land
use data is irrelevant for these apps, all that is needed is
continental outlines, MAJOR lakes, rivers, islands and cities).

So, why the interest in these maps?

Many amateur radio antenna are directional (doing a better job of
receiving (or transmitting) a signal in one particular direction).
With an azimuthal equidistant projection map done for your location,
you can draw a line from the center of the map to the location you are
interested in and that will instantly tell you the direction to adjust
your directional antenna. This is static map, as in you generate the
map once for a given latitude / longitude you are effectively done.

High frequency radio signals can refract off the ionosphere allowing
very long range communications with low power transmitters. What
frequencies refract well depends on a number factors, including
sunshine / darkness. So knowing that the place you want to talk to is
in darkness is useful. So, a day night map would have to be dynamic,
being updated say once per minute ...

Anyone with ideas as to where I could / should turn for the above?

Thanks.

Colin McGregor
VE3ZAA