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20000717: ldm-mcidas PNG converter (cont.)

>From: address@hidden
>Organization: Oregon State University
>Keywords: 200007131800.e6DI0rT09575 WXP McIDAS AREA


>I have some additional concerns that perhaps you can help with.
>First off, we we not able to correctly plot (using xsat and WXP) the 
>experimental CIMSS data decoded with "pnga2area".

Hmm.  Is there any clear indication of what in the image WXP does not
like?  Just a curiosity...

>So we are converting to using MCIDAS version 7.5 for plotting. This is
>probably a good move and one we have been putting off for some time.

OK.  I want to let you know that the current release of Unidata McIDAS-X
is 7.612 (the '12' reflects bugfixes and additions to 7.60), and I
am in the process of putting together my 7.70 release.

>Since we already have a system setup to plot data when it arrives through
>IDD,  we'd like to keep that system running with minor changes.  We just
>plan on replacing xsat with MCIDAS.  However, our system relies on the
>creation of AREA files with designated numbers (eq. AREA0130-133 for GOES
>west IR).  "lwtoa3" would automatically create files with the appropriate
>name.  At least from what I can find in the pnga2area man page, the user
>now supplies the file name.

'pnga2area' has two different personalities: one where you can specify
the name of the output file and another where you can continue to play
by old McIDAS rules (e.g., the McIDAS file routing system).  The latter
is activated by use of the '-d' (directory for output of the decoded
image) and '-r' (for the use of the McIDAS routing table concepts) flags.

>Right now for the LWTOA3 data, I can get the AREA number by pattern extraction
>in pqact.conf.  I looked at the experimental CIMSS data and I can't find that 
>same cycling of sequence numbers.  For example, Cloud Top Pressure data should
>have an AREA number of 1100-1109 yet all I see in the data stream is number 
>1100.  Is this functionality changing?

The default AREA file number in the broadcast will cause result in the
creation of one file for each type of product:

AREA name  Product
AREA1100   Cloud Top Pressure
AREA1110   Precipitable Water
AREA1120   Sea Surface Temperature
AREA1130   Lifted Index
AREA1150   Ozone

One can, however, use the McIDAS routing table to put the decoded images
into any set of AREA file numbers that you like.

You note that your GOES West IR images are being filed into AREAs 130 -
133 right now.  This tells me that you are accepting the defaults that
are specified in the product headers in the datastream and not using
the McIDAS routing table concept.

Here is a blow-by-blow of how you can use the McIDAS routing table to
determine the names of the images decoded from the Unidata-Wisconsin
datastream.  Don't perform these steps until you have read and understood
all of the steps that need to be taken.

o you will find a file named ROUTE.SYS in the ~mcidas/workdata directory
  and a file named SYSKEY.TAB in the ~mcidas/data directory of your
  McIDAS-X installation.  Copy these files to the directory in which
  you are decoding AREA files.  Change the read/write permissions on
  both of these files so that the user running the LDM has read and
  write access to them.

o since you are relying on the default names for the products currently
  in the datastream, you will need to modify the routing table entries
  for the products you are already getting.  I include the McIDAS commands
  that you need to run (or put in a McIDAS BATCH file and run) here:

ROUTE ADD UC AREA   60   63 CC=3 SYS=2170 2171 2172 "Educational Floater II
ROUTE ADD UX AREA  100  103 CC=3 SYS=2122 2123 2124 "Mollweide Composite IR
ROUTE ADD UY AREA  110  113 CC=3 SYS=2152 2153 2154 "Mollweide Composite H2O
ROUTE ADD U9 AREA  120  123 CC=3 SYS=2116 2117 2118 "GOES-West Western US VIS
ROUTE ADD U5 AREA  130  133 CC=3 SYS=2113 2114 2115 "GOES-West Western US IR
ROUTE ADD UV AREA  140  143 CC=3 SYS=2146 2147 2148 "GOES-East North America VIS
ROUTE ADD UI AREA  150  153 CC=3 SYS=2143 2144 2145 "GOES-East North America IR
ROUTE ADD UA AREA  160  163 CC=3 SYS=2101 2102 2103 "Educational Floater I
ROUTE ADD UB AREA  170  173 CC=3 SYS=2104 2105 2106 "GOES-West Western US H2O
ROUTE ADD UR AREA  180  183 CC=3 SYS=2107 2108 2109 "Research Floater
ROUTE ADD U1 AREA  190  193 CC=3 SYS=2119 2120 2121 "Antarctic IR Composite
ROUTE ADD U3 AREA  200  205 CC=3 SYS=2110 2111 2112 "Manually Digitized Radar
ROUTE ADD UW AREA  210  213 CC=3 SYS=2149 2150 2151 "GOES-East North America H2O

  You will note that the 5th and 6th columns reflect the AREA numbers
  that you are used to:  4 numbers for all image products EXCEPT the
  manually digitized radar which has 6.

  The following are the equivalent set of commands that will will need to
  run for the CIMSS products.

ROUTE ADD CA AREA 1100 1103 CC=3 SYS=2173 2174 2175 "Cloud Top Pressure
ROUTE ADD CB AREA 1110 1113 CC=3 SYS=2176 2177 2178 "Precipitable Water
ROUTE ADD CC AREA 1120 1123 CC=3 SYS=2179 2180 2181 "Sea Sfc. Temperature
ROUTE ADD CD AREA 1130 1133 CC=3 SYS=2182 2183 2184 "Lifted Index
ROUTE ADD CE AREA 1140 1143 CC=3 SYS=2185 2186 2187 "CAPE
ROUTE ADD CF AREA 1150 1153 CC=3 SYS=2188 2189 2190 "Ozone

  The form of the ROUTE commands listed above show that one can control
  the namespace of the decoded product to:

  o any legal McIDAS AREA name (AREA0001 - AREA9999)
  o any set of names where the AREA file numbers don't conflict

  So, if you decided that you wanted to keep 10 of each product, you could
  change the ending number from ...'3' to ..'9'.  In fact, we send out
  the routing table configured to save 10 each of the images.  For more
  information, you can review the contents of the file ~mcidas/data/DROUTE.BAT
  in your McIDAS-X installation.

o Start a McIDAS-X session:

  o login as the user 'mcidas'
  o make sure that MCDATA, MCPATH, MCGUI have been defined as per the
    online instructions in the McIDAS-X web pages.  For example, this
    might look like (C shell syntax for setting the environment variables):

    setenv MCDATA /home/mcidas/workdata
    setenv MCPATH ${MCDATA}:/home/mcidas/data:/home/mcidas/help
    setenv MCGUI  /home/mcidas/bin

  o type 'mcidas'

o From the McIDAS Text and Command window, define a REDIRECTion to the
  copies of ROUTE.SYS and SYSKEY.TAB that you copied in a step above.
  For the purpose of illustration, assume that the directory into which
  you are decoding your data files is /data/ldm/mcidas.  The McIDAS
  commands that define the needed REDIRECTions are:

  REDIRECT ADD ROUTE.SYS "/data/ldm/mcidas
  REDIRECT ADD SYSKEY.TAB "/data/ldm/mcidas

o Verify that you can access the ROUTE.SYS and SYSKEY.TAB copies:


o After you have determined that you can access the files, you can update
  them with the routing definitions I listed above.  For simplicity I
  suggest putting all of the ROUTE commands I listed above into a
  single file, ~mcidas/workdata/ORSTRTE.BAT.  Using this file, update
  ROUTE.SYS and SYSKEY.TAB by running the following:


o Verify that ROUTE.SYS was, in fact, updated:


  The routing table listing should show beginning and ending file
  numbers (referred to in McIDAS as cylinder numbers) that match
  the numbers in the ROUTE commands that you put into ORSTRTE.BAT.
  If the listing does not reflect the proper numbers it is most
  likely that the file permissions on ROUTE.SYS and SYSKEY.TAB do
  not allow read and write access by the user 'mcidas'; they need to!

After modifying the routing table, the images that are decoded by
both 'lwtoa3' and 'pnga2area' will begin with the first AREA file
number for each product.  If your product generation scheme somehow
assumes that a particular product number image comes in at a particular
time, then you must rethink how you are generating your products (the
time-to-AREA file number match was never guaranteed, but may have
in place nonetheless).

At some point in the future, you will probably want to revisit how
you are generating products so that you can move away from the very
restrictive, and inpenetrable McIDAS AREA file names of old.

>In addition, will the change in the data stream be a transition (eg. both 
>formats of data in IDD for a short time period) or an immediate change after a
>given date and time?

We have talked about this internally a bit.  It would seem that
you would find it useful in making a graceful transition from one
compression scheme to the other.  Am I correct in this?  If so, we
will even more strongly consider concurrently broadcasting the old
and new formats.

>Thanks for your help,

You are welcome.  Please don't hesitate to ask for advice on setting
up the McIDAS routing table use.


>From address@hidden Tue Jul 18 16:02:31 2000
>Subject: Re: 20000717: ldm-mcidas PNG converter (cont.)


Thank you for the extensive explanation you sent yesterday on MCIDAS.
We're working on the implementation.

A graceful transition would be a better solution for us.  If problems
occur, we can revert back to the older compression format for the AREA
files and work on the new system in parallel.

Wayne Gibson
Oregon State University

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