[NLRS] Is there published data on tree foliage ...

[Chris Elmquist]

On Friday (07/11/2014 at 10:33AM -0500), Doug Reed wrote:
> 
> You have to remember that a DTV signal displays NOTHING unless the
> digital data can be decoded and corrected by the software in the
> converter box. Only when the signal can be decoded will there be a
> picture. Either it is correct and 100% accurate or there is nothing.
> The Bit Error Rate (BER) display is probably going to go from 100% to
> zero with very few stops in between, like the square edge on a table,
> but come back just as fast.

Is the degradation of the bit stream that acute though really?

Isn't the "pixelization" that one experiences the result of portions of
the stream being lost due to destructive interference and are what results
from an increased BER without totally loosing the stream all together?

I experience this sort of failure much more often than a total outage of
the picture.

I think you can have a fairly high BER and the FEC in the protocol will
correct a lot before it starts to manifest as pixelization or total loss
of the image.

> <http://www.digitalproceiver.com/modsci/public/images/whitePapers/televisionproducts/msi4400a/measuring%208vsb.pdf>
> This PDF is a good description of ATSC broadcasting and reception and
> about slide 15 it has pictures and discussion of how to decode and
> display the data, then evaluate it. It may answer some questions.

Yes. That's a good presentation.

I think as others have mentioned, the equalizers in the front-end of the
receiver have a lot of impact on reception "quality" too.   So then it
gets down to implementation of the receiver and how good of a job they
did with the design.   To me, this explains the wildy different behavior
I see across multiple receivers here, all connected to the same antenna.

Chris N0JCF
-- 
Chris Elmquist