LF: Re: Calculating ERP from measured field strength

["Dick Rollema" <d.w.rollema@freeler.nl>]

To Reg, G4FGQ and the LF-group

Reg, G4FGQ wrote:

Yes, I am aware of that.  But I am interested in the extent to
which VLF
> predicting capability of program
> GrndWav3 is affected by skywaves.  It would
> be nice to state confidence limits on predicting error,  + or - dB
> or
> something like that.
>
> Any info is better than none. I have no means of making any
> measurements
> myself.  So should some very inacurate data turn up it would be
> of
> interest.
I would like to provide this data. But my problem is that
in order to do a reliable measurement the signal has to be sufficiently
over the local noise level. This means it must be about S6 or more.
Signals you would like to be measured do not come up to that level. 
But in order to find out whether a signal is affected by sky wave you
could monitor the strong commercial stations adjacent to our LF band.
When they vary in strength with time that is an indication there is a mix
of ground and skywave. 

73, Dick, PA0SE