Again , many thanks for the flow of info
10W , the rotation rate details are excellent , thanks.
This is all an unexplored area for us and the data here is helping to build the picture.
Tigersaw.... I have been experimenting with rotation against location and it confirms your comments re exact location....in a simlar way that for Planeplotters multilateration system we need pinpoint accuracy for our ground station location [ of which we now have over 300 ]
MarcK . . . I know our US users are having some difficulty . Whilst an FOIA revealed the site locations State by State , they are struggling with a lack of SI/II data.
Back here in the UK , some observations.
From our findings it seems that some Mode A/C sites are only operational at certain times.
I have an unknown site near Teeside which for example seemed to close down at the weekend.This leads me to think its possibly a little further south than I thought and may be Leeming
Some sites , such as Clee Hill give poor results no matter what we do . I suspect CH may be a cluster type array.
John