[mmaimcal] sources of noise

[Harvey Liszt]

Leonia--

The 1/f-like noise that Al is talking about is actually a gain (G) variation
and the noise contribution it actually makes is from the "other" term
in the radiometer equation, which is usually neglected, i.e. a term which
in quadrature adds to the other noise like (delta G/G)**2. 

Of course the gain variations also have some frequency dependence, as the
gain does, but on the whole the 1/f noise is coherent across the band, as
the whole passband breaths on short time scales.

Also is isn't strictly 1/f (I think its more like 1/sqrt(f)).

regards, Harvey

> 
> 
> Mark,
> 
> You wrote:
> 
> >I think the noise from the sky brightness fluctuations is correlated
> >across frequency channels.
> 
> It sounds strange for me. 
> 
> The signal received by the receiver is the sum of the three noises:
> 
> Noise of the source 
> Noise of the receiver and 
> Noise of the "sky".
> 
> Noise of the source and receiver are uncorrelated across frequency channels.
> The noise of of the "sky" should be uncorelated also.
> 
> May be you are speaking about something different?
> 
> Leonia
>