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20041103: Some questions.....

>From:  "Kevin Polston" <address@hidden>
>Organization:  NOAA 
>Keywords:  200411032219.iA3MJ6vV015636 McIDAS enhancement LDM ldmd.conf 
>pqact.conf GEMPAK NEXRAD Level II composite

Hi Kevin,

>I have a couple of quick questions I hope you have the answer to. The first
>one regards an enhancement file for the 1km FNEXRAD imagery.  There is an
>example on the Unidata website (here is the link http://my.unidata.ucar
>edu/content/data/images/1kn0r_local.gif) of the resolution of the 1km
>composite radar imagery. Would you by chance have that enhancement that is
>used in that example and if so could you send it to me please.

The display and associated enhancement are from McIDAS. The listing of
the McIDAS enhancement is:

 Brightness  Blue      Green      Red
  min max   min max   min max   min max
  --- ---   --- ---   --- ---   --- ---
    0   2     0   0     0   0     0   0
    3  85     2 128     0   0     0   0
   86  96   240 240   240 240     0   0
   97 107   144 144   144 144     0   0
  108 119    80  80   224 224   128 128
  120 130    64  64   184 184   100 100
  131 141    48  48   144 144    72  72
  142 153    32  32   104 104    44  44
  154 164    16  16    64  64    16  16
  165 175    16  16   192 192   240 240
  176 187    32  32   128 128   240 240
  188 198    32  32    16  16   240 240
  199 209     0   0     0   0   144 144
  210 221   128 128    32  32   176 176
  222 232   160 160    64  64   202 202
  233 243   255 255   255 255   255 255
  244 255   224 224   128 128   255 255
EU: Done

If you are not familiar with a McIDAS EU listing of an enhancement table,
it shows the Blue, Green, and Red gun settings for ranges of brightness
levels.  The only section of the enhancement that uses a ranging of
gun levels over a brightness range is the second from the top where
the Blue gun varies from 2 to 128 (full range is 0 to 255) as the brightness
ranges from 3 to 85.

>I have tried
>to recreate it and I have come close (and have a good enhancement I use now)
>but after seeing that particular enhancement I was hoping I might be able to
>get it. If not it is not a big deal but it would be nice to have.

Give the listing a shot and see if it helps.

>Second, I have searched the e-mail archives and could not find how to setup
>your ldmd.conf file and the pqact.conf file to receive the Level II radar
>data. What entries would I have to make in both files to receive this data.

The Level II data is requestable using several different feed names
all of which are equivalent:  CRAFT NEXRD2, and NEXRAD2.  The latter
mnemonmic is known only in LDM-6.1.x.

So, an ldmd.conf request line that would get all Level II data is:

request NEXRAD2 ".*" upstream_feed_host

pqact.conf actions that would be used to FILE process the data (used
by GEMPAK) are:

# CRAFT stored as raw bz2 for GEMPAK
# file the raw data to a temporary file beginning with "." so that autoupdate 
GUIs don't
# get ugly partial volume plots
        FILE    data/gempak/nexrad/craft/\1/.\1_\2_\3
# Done to move file after last record is received "/E" to prevent
# autoupdate from seeing partially received files (dccraft_move is a shell 
script copied from $NAWIPS/bin/scripts)
        EXEC    util/dccraft_move data/gempak/nexrad/craft/\1/.\1_\2_\3 
# CRAFT stored uncompressed (not needed for GEMPAK 5.7.2p2 and later)
        PIPE    decoders/dcnexr2 -s \1 -d /dev/null 

As always, make sure that there are tabs where needed for pqact.conf

>And if I only wanted certain sites I suppose I could choose that option as

Right.  Use the LDM 'notifyme' utility to list the headers of the
Level II products from an upstream host that has allowed you and
is getting the data to see what the headers look like and then create
a regular expression that gets just the radars you want.

>I have heard that the Level II data is very large.

The NEXRAD2 feed is the second in terms of volume of all IDD datastreams.
It is frequently the largest in terms of numbers of products (each
400 radials is sent out as a product).

>My next question is less a question and more of a suggestion.  Are there any
>plans to have a national VIL product in the FNEXRAD stream.....like the
>reflectivity and precip totals imagery now?

No, not really.  We have not had many sites request such a product.  In
fact, the only site that has asked for it is you.

>I think that would be pretty
>nice to have. I don't know if there are plans for that or not but in case it
>hasn't been suggested I would like to suggest that.  :-)
>My final question is this......is the SPC Mesoscale Discussion graphic areas
>being sent out in the Redbook Graphics datastream?

I don't know.  Chiz is the expert in RedBook Graphics products.

>The reason I ask is that
>I am receiving the Redbook Graphics but I haven't found the SPC MD directory
>or files. I don't know if I would need to update the pqact.conf file or not
>(since it seemed like I was getting all the redbook graphics currently.) I
>just haven't seen it, maybe I am expecting a different header but I can't
>seem to find it.  Hopefully you can shed some light on this for me.

You can always use the notifyme command pointed at your upstream IDD
relay and see the full set of product headers in any particular stream.
That way, you will know if you are requesting all that you should be.
If your request regular expression is a ".*" you will get all that
the upstream site has.

>Thanks Tom, I appreciate your help as always.

No worries.

>Kevin Polston
>Senior Instructor, NWSTC
>Kansas City MO 64152
>816-880-9314 ext 273


* Tom Yoksas                                             UCAR Unidata Program *
* (303) 497-8642 (last resort)                                  P.O. Box 3000 *
* address@hidden                                   Boulder, CO 80307 *
* Unidata WWW Service                             http://www.unidata.ucar.edu/*

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