Indeed, this needs much more analysis.
the ship is on the move again, left Brockville around 16:40 UTC and now
headed a little further downstream to Prescott
Grids have been changing from do to eo and now ep.
Consider this pair of wspr spots:
2017-06-07 17:02 CG3EXP 14.097116 -25 -2 FN24ep 0.2 K4RCG FM08si
2017-06-07 17:00 CG3EXP 14.097116 -16 -2 FN24eo 0.2 K4RCG FM08si
both from the same receiving site and for the same 2x wspr sequence (i.e.
two sequential transmissions) in order to encode/decode the six digit
grid.
Notice at hh:00 the grid was ep and hh:02 is eo. This makes sense with
respect to the route the ship is travelling, Prescott is NE down the
rive from Brockville.
Same pattern earlier when the ship started to move out of Brockville:
2017-06-07 16:42 CG3EXP 14.097108 -18 -2 FN24eo 0.2 K9AN EN50wc
2017-06-07 16:40 CG3EXP 14.097110 -16 -3 FN24do 0.2 K9AN EN50wc
do at hh:42 then eo at hh:42 this time Eastward but still continuing the
general NE path to the next destination.
I don't know enough about the software on the U3 nor the encode/decode
process (but I am slowly figuring it out) but these two noted changes at
least make sense with respect to the movement of ship and that it seems
as though something changed between the first and second transmission
and the respective spots are being reported correctly.
things that make you go hmmm.....
cheers, Graham ve3gtc
On 6/7/2017, "Alan via Groups.Io" <alan4alan@...>
wrote:
I have been watching CG3EXP's spots with respect to their sometimes
wandering nature with their grid squares.
Graham
Looking at the last 1000 spots when it has obviously been moving 998 of
them are in the expected sequence, one or both of the last letters
changing by one character.
Two stations reported FN14sf out of sequence at 03.40 but maybe we can
ignore that.
But it was stationary when, for example, FN14sf to FN14vg in 22 minutes
was reported.
But since 21.22 yesterday UT FN24do has been reported by all... Just the
two odd ones in a thousand, moving or not.
I think Hans is right, some strange bug in one or more versions of WSPR,
maybe something like a false decode?
Perhaps you need to look at more than just one station to see the
effects of different decoders?
Or is it possible some GPS QRM? I'm not sure if it still happens but I
think there have been a number of jamming tests in the past. Or radar etc?
And where is the GPS antenna?
73 Alan G4ZFQ
