[aprssig] APRS coverage maps for the American West

[Robert Bruninga]

Allan,
great work!  The APRS data is a global resource and it is
nice to see people taking the initiative to dig into it and
see what they can discover about the network.

I wonder though about the areas which might show
reduced coverage.  As you suggest, it might be better
to say this is a plot of APRS user density than maybe
coverage.  As you note, the data is restricted to only
one packet per mobile per hour.    So at a 2 minute 
mobile rate, that means a full 120 mile stretch wouild
only get on dot per mobile.

Since this data was only for 1 month, then you would
need more than 120 mobiles per month to travel some
of those distant roads to even fill the road even if
it had perfect coverage.  Then there is the second
order effect of somewhere along that road is a
hill and a great place for a packet to get out.
ALL mobiles along that road will get in from that
point, yet the 1 hour filter will throw away all other
points.  Now then the map will only show that one
high spot with one dot, even though dozens of
mobiles may have contributed to that one dot, and
then because of the 1 hour filter none of their
other spots show up.

Anyway, just something to think about....

Bob
>>> apratt at bestbits.org 05/07/06 1:57 AM >>>
As I threatened to do a little while ago, I have taken three months'
worth of data from the APRSWorld archives and used it to create
coverage maps for California and the American West.

You can go to http://www.bestbits.org/aprs to see the results of my
study. (Follow the "Coverage maps" link.)

The data I used is not complete: it only stores one position per
station per hour. Also, the data doesn't support a "hop count" study,
and I couldn't tell if any reports were from stations that were
feeding APRS-IS directly (not over the air). You can see more about
what I did by going to the report page on BestBits.

Thanks everybody for the help and info. Who knows? I might keep
fiddling with this and maybe do it again for the Eastern US.

-- Allan Pratt, apratt at bestbits.org

_______________________________________________
aprssig mailing list
aprssig at lists.tapr.org
https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig