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[McIDAS #AIT-655217]: Ticket ID: FVC-112860

Hi Paul,

re: various flagged data levels in Level III products

> OK...I have not seen RF color levels on any of the enhancement tables. Can
> you tell me the values for these?

I will go through the documentation and dig out which value is to be
interpreted as Range Folded (RF).

> Would there be RF for echo products as well?

No.  RF is for velocity products only.  Reflectivities have a ThresHold
(TH) value (which you will see in BAR labels).

> BT...on the bottom of the BAR there is a "TH" i have no idea what
> that means.

TH stands for ThresHold.

re: itseems that you are intent on making the new "high resolution"
products look like the old "low resolution" products.

> Not for all of them. I am really at looking at velocity and reflectivity
> products to make the color levels better and consistent.


> Take a look at this
> http://climate.cod.edu/data/nexrad/GRR/N0Q/GRR.N0Q.20120130.1438.gif
> This was done with the BREF24 ET  I do not like the interval nor the color
> table. I want MORE variance so we did this:
> http://climate.cod.edu/data/nexrad/GRR/N0Q/GRR.N0Q.20120130.1436.gif
> I think ours looks like better resolution, more in-line with what GRlevel3
> can do...not so "VIP" like

Both SSEC and I looked for "official" color tables to include in McIDAS
so that user's displays would match those used by the Weather Service.  Since
I found no documented "official" enhancements, I stuck with what was already
in the Unidata McIDAS distribution.  SSEC found an "experimental" enhancement
for the high resolution reflectivities, and they created a McIDAS enhancement
based on it.  I include all of the SSEC enhancements in the Unidata McIDAS
release.  The enhancement in question is WSR-BREF-16.ET.  As soon as I
find out what AWIPS-II will be using, I will replicate the enhancements
in the Unidata McIDAS release.

> This is more in-line with your distributed palette of WSR-BREF.
> http://climate.cod.edu/data/nexrad/GRR/N0Q/GRR.N0Q.20120130.1452.gif
> In this example, the strong border between 55 and higher DBZ's is what we
> are after. But I want that color split ALWAYS at 55DBZ. And I want the
> interval to be labeled at 10DBZ, not 8.

I understand what you are after.  I think that this will be challenging
given how the products define their data levels.

re: other products

> Some of the other products look alright to me for now.

OK.  Since I didn't know what the full scope of what you are after was,
I answered the way that I did.


> Right - but I believe that the Digital reflectivity always gives the FULL
> range of reflectivities whether or not the radar is operating in clear air
> or precip mode. Notice on the images i sent you the whole array from -30
> to 90 is there which I *think* is the data limit for Level 3 products.

I believe that this is correct.  Why the radar folks chose to not fix
the data levels for reflectivity is anyone's guess.

> As far as velocity is concerned, I would think a +/- 100kt interval would
> be sufficient with any values beyond that coming in and assigned to
> brightness level 255 (or 0) I just want consistency for the end user that
> colors are what matters. We will be placing these on the web so
> interrogation is not possible anyway. And we will loop the images and need
> the same color bar for each.

Again, you will run into BIG problems for some of the dual pol products when
you loop them -- the mapping between data levels and colors can not be forced
into a single range while maintaining the precision in value-to-value variance.
At least, that is how I interpret the ICD that describes the products.


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Ticket Details
Ticket ID: AIT-655217
Department: Support McIDAS
Priority: Normal
Status: Closed

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