Re: 20021023: 20021023: converting GINI composite radar image values to dbZ

Cool.  Yes, the values I'm getting from the bit of code I just wrote to
decode this correspond exactly to those in the table.   Thanks again for
making these composites.  They're great!

----- Original Message -----
From: "Unidata Support" <address@hidden>
To: "David Wojtowicz" <address@hidden>
Cc: "Unidata Support" <address@hidden>
Sent: Wednesday, October 23, 2002 6:03 PM
Subject: 20021023: 20021023: converting GINI composite radar image values to
dbZ


>
>
> David,
>
> Correct. Forgot to mention the units bytes and the scaling by 10000.
>
> The $NAWIPS/unidata/programs/nex2gini program I created uses the
> data blocks in the $GEMTBL/unidata/nex2gini.tbl file for
> the varous "stretch" sections. In the case of N0R, there is only 1
> calibrated range. For, N1P there are 3 (because the LevelIII
> bins for the data range are much larger at the high end and the
> difference between ND and "0.00").
>
> The table I'm using currently looks like:
> !
> !
> !Prod   band ncal units,Calval_1;....;calval_n  Prod_header
> N0Z       25    1 dBZ,0,255,0,75            TICZ99 CHIZ
> NET       26    1 KFt,0,255,0,85             TICZ99 CHIZ
> N0R       27    1 dBZ,0,105,-30,75           TICZ99 CHIZ
> NCR       28    1 dBZ,0,105,-30,75           TICZ99 CHIZ
> NVL       29    1 Kg/m**2,0,255,0,85         TICZ99 CHIZ
> N1P       30    3 inches,10,110,0,2;110,210,2,6;210,255,6,12      TICZ99
CHIZ
> NTP       31    3 inches,10,110,0,4;110,220,4,12;210,255,12,24     TICZ99
CHIZ
>
> Steve Chiswell
> Unidata User SUpport
>
>
> >From: "David Wojtowicz" <address@hidden>
> >Organization: UCAR/Unidata
> >Keywords: 200210232255.g9NMtTp06497
>
> >
> >----- Original Message -----
> >From: "Unidata Support" <address@hidden>
> >To: <address@hidden>
> >Cc: <address@hidden>
> >Sent: Wednesday, October 23, 2002 4:58 PM
> >Subject: 20021023: converting GINI composite radar image values to dbZ
> >
> >
> >>
> >> David,
> >>
> >> I provide a calibration block in the image (in the unused portion
> >> of the GINI header) that is used to obtain the image calibration bar
> >> values.
> >>
> >> I created a section of code in $GEMPAK/source/gemlib/im/imgi2gm.f
> >> with:
> >> C
> >> C*      Get calibration Block if it exists.
> >> C*      Currently, only Unidata calibrations exist, using
> >> C*          Word 47 = 128
> >> C*      to signal that a calibration block is present.
> >> C
> >> At present the format is the number of calibration ranges N, followed
by
> >> N * 4 values where each set of 4 represents the pixel min, max and
> >> data value min max they corespond to.
> >>
> >Steve thanks for the info.
> >
> >I was a bit confused at first, but it looks like starting at Octet 48,
there
> >is:
> >
> > 1) a space padded 8 byte character array with the name of the units
> > 2) followed by a 1 byte size, N
> > 3)  followed by N*4 4-byte values (words) that correspond to the values
you
> >mention above that are multiplied by 10000
> >
> >Is this the correct interpretation of the Unidata calibration section?
> >
> >Thanks!
> >
>
>
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