20030618: Overlay point data with frame time (cont.)

>From: "Kwan-yin Kong" <address@hidden>
>Organization: CCNY
>Keywords: 200306171633.h5HGXmLd000512 McIDAS DSSERVE 

Kwan-yin,

>      Well, I am trying PTDISP and PTCON.  I would like to 
>plot station models on an image, then overlay it with 
>sea-level isobars and surface isotherms.  I can get a 
>station model plot using the SFCPLOT command.  But I do 
>not want the station ID to appear in the station model to 
>make it look less clutered.

You can change how things are plotted with SFCPLOT and contoured by
SFCCON by creating a configuration file for each.

The default configuration file for SFCPLOT is SFCPLOT.CORE, and the
default configuration file for SFCCON is SFCCON.CORE.  The default
files will be located in the ~mcidas/data directory of your
installation.

If you want to customize the existing definitions in SFCPLOT.CORE so
that they will be usable by all McIDAS users, make a copy of
SFCPLOT.CORE named SFCPLOT.SITE and put it in the same directory as
SFCPLOT.CORE, ~mcidas/data.  If any individual user wants to create
his/her own customization, he/she should create a SFCPLOT.USER file in
his/her McIDAS working directory.  The working directory for Unidata
McIDAS is defined by the user's MCPATH environment variable.  It is
~mcidas/workdata for the user 'mcidas' and ~/mcidas/data for all other
users.

The order of precedence for a configuration definition is:

SFCPLOT          SFCCON
----------------+-----------
SFCPLOT.USER     SFCCON.USER      <- will be used first
SFCPLOT.SITE     SFCCON.SITE      <- will be used if not in SFCPLOT.USER
SFCPLOT.CORE     SFCCON.CORE      <- will be used if not in SFCPLOT.USER
                                     or SFCPLOT.SITE

You will see in SFCPLOT.CORE that you can "tell" SFCPLOT who to create
a station model plot:

PLOT.PMSL    UNIT=AMERICAN METRIC \
             AMERICAN='F F X MB KTS' METRIC='C C X MB KTS' \
             COLOR='2 2 3 3 4 3' \
             FORMAT='I3 I3 X K3 FLAG' \
             LSIZE='6 6 6 6 8 5' \
             MULTIPLY='1 1 1 10' \
             OFFSET='-8 -15 8 -15 X -20 -8 8 X X 8 8' \
             LOC=+ \
             TITLE=X 3 \
             FONT=' '\
             ISFC='T TD WX1 PRE WIND ID ' \
             SVCA='T TD WX1 PRE WIND ID ' \
             SYN= 'T TD WX1 PSL WIND ID ' \
             ISHP='T TD WXP PSL WIND IDA'


The way you read this is as follows:

For MD files containing ISFC data (standard decoded SAO/METAR data),
the parameters to plot are:

             ISFC='T TD WX1 PRE WIND ID ' \

The units to use for these parameters are:

             AMERICAN='F F X MB KTS' METRIC='C C X MB KTS' \

The color of the items plotted are:

             COLOR='2 2 3 3 4 3' \

The format for the plot are:

             FORMAT='I3 I3 X K3 FLAG' \

The size of the items to plot are:

             LSIZE='6 6 6 6 8 5' \

etc.

The hardest item to grasp is the OFFSET value(s).  This/these tell
McIDAS where to place the plot item relative to an imaginary grid
around the exact loction of the observation:

        -4  -3  -2  -1   0  +1  +2  +3  +4

     +3  .   .   .   .   .   .   .   .   .

     +2  .   .   .   .   .   .   .   .   .

     +1  .   .   .   .   .   .   .   .   .

      0  .   .   .   .   x   .   .   .   .

     -1  .   .   .   .   .   .   .   .   .

     -2  .   .   .   .   .   .   .   .   .

     -3  .   .   .   .   .   .   .   .   .


'x' marks the center of the box, and the box extends beyond what is
illustrated here.

To get a feeling for how this works, I recommend that you:

- create an SFCPLOT.USER as an exact copy of SFCPLOT.CORE in your
  McIDAS working directory

- choose one definition and experiment by changing values and seeing the
  results

>So I've just found out that 
>PTDISP allow specifying what parameters are to be plotted 
>on the station model (and colors as well).

So does SFCPLOT.

>As for 
>contouring isobars and isotherms, I am looking for a 
>keyword that can specify smoothness for the contours.  I 
>find that the surface isotherms need to be analyzed with a 
>"sharper" radius of influence than the default setting in 
>SFCCON.  These are the reasons I am trying out PTCON and 
>PTDISP.

OK.

>As far as getting the time of the current frame, I 
>actually wrote a GETTIME.MCB a while ago for that purpose. 
>It stores the date and time of the image in two strings 
>(see below).

Cool!

>REM ? GETTIME.MCB - obtain the day and time of the image displayed on the
>REM ?               current frame, then store them in strings #IMGD and #IMGT.
>REM ?
>REM ? Invocation:  
>REM ?      RUN FILE=GETTIME.MCB
>REM ?
>REM   History: Created 09/14/2002 
>REM Definition of variables used in the following:
>REM REM       Variable      Use 
>REM Internal: D$         DAY of original image 
>REM           T$         TIME of original image 
>REM
>  10  PRINT "Retrieving the Julian day and time of the image on current 
> frame..."
>      KEYIN "FRMLIST X DEV=FNN FRMLIST.OUT"
>      OPEN "FRMLIST.OUT",10,80
>      INPUT @10,A$:INPUT @10,A$:INPUT @10,A$:INPUT @10,A$
>      CLOSE 10
>      PRINT "Frame #";MID$(A$,8,2);": ";
>      IF MID$(A$,17,2) = "No" PRINT "ERROR! ";MID$(A$,17,20);"!":STOP
>
>  12  D$=MID$(A$,36,5)
>      T$=MID$(A$,42,2)
>      PRINT "Julian day and time of image is ";D$;"-";T$;"Z"
>      KEYIN "DATELIST ";D$;" FORM='(YYYY)(MM)(DD)' DEV=FNN DATELIST.OUT"
>      OPEN "DATELIST.OUT",11,80
>      INPUT @11,A$: CLOSE 11
>      PTABLE MID$(A$,1,8),"IMGD"
>      PTABLE T$,"IMGT"

Tom