Parent Topic: <A href="http://www.pcigeomatics.com/cgi-bin/pcihlp/SST">SST</a><hr>
<H3>PARAMETERS</H3>
SST is controlled by the following global parameters:
<P>
<pre>Name     Prompt                                  Count     Type
FILI     Database Input File Name                1-64      Char
FILO     Database Output File Name               1-64      Char
AVHRRCHA Input Channels with AVHRR Bands 3,4,5   3         Int
DBOC     Database Output Channel List            1         Int
AVHRRSEG AVHRR Calibration/Orbit Segment         0-1       Int
SENSFILE AVHRR Sensor Information File           1-64      Char
MCCLAIN  McClain Coefficients                    0-4       Real
REPORT   Report Mode:  TERM/OFF/filename         1-64      Char
</pre>
<H4>FILI</H4>
Specifies the name of the input file which contains the raw AVHRR
image data (AVHRR thermal channels 3, 4, 5), and the AVHRRSEG text
segment. The input file must be a PCIDSK file (created using FIMPORT
or MIAVHRR) or an actual AVHRR disk file. If FILI and FILO are the
same, FILI must be a PCIDSK file (it cannot be an AVHRR disk file).
<P>
<PRE>
 EASI&gt;FILI=&quot;filespec&quot;
</PRE>
<H4>FILO</H4>
Specifies the name of the PCIDSK file which will receive the sea
surface temperature results. FILO must be specified and it must
exist. SST does not create a new output file. FILO can be the same
as FILI as long as the file type is PCIDSK.
<P>
<PRE>
 EASI&gt;FILO=&quot;filespec&quot;
</PRE>
<H4>AVHRRCHA</H4>
Specifies the three channels in the input file containing the AVHRR
thermal channels (3,4,5).
<P>
<PRE>
 EASI&gt;AVHRRCHA=avhrr3,avhrr4,avhrr5
</PRE>
For example, if AVHRR channels 3,4,5 were read into channels 1, 2,
and 3 of the input file by the program MIAVHRR then specify AVHRRCHA
as follows:
<P>
<PRE>
 EASI&gt;AVHRRCHA=1,2,3            | AVHRR channels 3,4,5
</PRE>
<H4>DBOC</H4>
Specifies the output channel to which the sea surface temperature
information will be written.
<P>
<PRE>
 EASI&gt;DBOC=j
</PRE>
It is recommended that this channel be a (32-bit) real channel so
that maximum accuracy can be preserved. However, it is possible to
use 8-bit and 16-bit channels with the following notes in mind:
<P>
<UL>
<LI> If a real channel is specified, the values are saved as computed.
</UL>
<UL>
<LI> If a 16 bit signed channel is specified, only the integer part of
the values are saved. (e.g., 3.7 is saved as 3) 
</UL>
<UL>
<LI> If a 16 bit unsigned channel is specified, only the integer part
of the values are saved and all negative values are set to 0.
(e.g., -2.5 is saved as 0; 3.7 is saved as 3) 
</UL>
<UL>
<LI> If an 8-bit channel is specified, the program will scale
temperature values between -4.1 and 21.4 degrees Celsius to the
range 0 to 255 using the following formula: 
</UL>
<PRE>
        (T + 4.1)*10    where T is the Temperature value

 for example:     T = -4.1; scale to 0
                  T = -4.0; scale to 1
                  T = -3.9; scale to 2
                    ...
                  T = 21.4; scale to 255
</PRE>
Temperatures less than -4.1 are scaled to 0. Temperatures greater
than 21.4 are scaled to 255. A pseudocolour segment is also
automatically generated so that the 8-bit sea surface temperature
results can be viewed in a visually pleasing manner. Please see the
PSEUDOCOLOURS section for further details.
<P>
<H4>AVHRRSEG</H4>
Specifies the text segment number containing the AVHRR
calibration/orbital data. This text segment is automatically created
when FIMPORT or MIAVHRR is used to read in an AVHRR image (from disk
or tape, respectively). If AVHRRSEG is not set, SST will try to find
a valid AVHRR text segment in the input file to use.
<P>
<PRE>
 EASI&gt;AVHRRSEG=j     | Use segment number j
 EASI&gt;AVHRRSEG=      | SST will try to find a valid text segment
</PRE>
This text segment (type 140) contains image specific information:
<P>
<UL>
<LI> Satellite Name, Year, Julian Day; 
<LI> Orbital Information (ASCEND/DESCEND); 
<LI> Platinum resistance temperature counts; 
<LI> Internal target count values for channels 3,4,5; 
<LI> Space count values for channels 3,4,5; 
<LI> Up to 5 LUTs used to compress 10-bit data to 8-bit data. Each LUT
corresponds to one AVHRR channel. 
</UL>
It is possible to change the values in this segment using the
program TEXWRIT, a system text editor, and TEXREAD. Be sure to
maintain exactly the same format as the original segment.<p>
For a detailed description of the AVHRRSEG text segment format,
please see the help for AVHRRAD.
<P>
<H4>SENSFILE</H4>
Specifies the satellite-specific sensor file. This is a text file
containing the following information:
<P>
<UL>
<LI> Platinum resistance temperature coefficients for converting
platinum resistance temperature counts into temperature values. 
<LI> Day and night McClain coefficients for AVHRR thermal channels. 
<LI> Sensor response information and non-linearity corrections for
each AVHRR thermal channel. 
</UL>
For NOAA-9/12/14, this sensor file is supplied by PCI and resides in
the &quot;/pci/etc&quot; directory (or &quot;\pci\etc&quot; on some systems). For
NOAA-14, the PCI supplied sensor file is named, &quot;sstnoa14.dat&quot;.<p>
By default, SST will look for the specified sensor file in the
current working directory. If not present, SST will look for the
specified sensor file in the PCI etc directory.
<P>
<PRE>
 EASI&gt;SENSFILE=&quot;filespec&quot;
</PRE>
<H4>MCCLAIN</H4>
Specifies the Multi Channel Split coefficients.
<P>
<PRE>
 MCSST Split Equation:

       Temperature (Celsius) =
          A * (Temp. Channel 4 - Temp. Channel 5) +
          B * (Temp. Channel 4) +
          C * ((Temp. Channel 4 - Temp. Channel 5) *
               (Secant of Satellite Zenith Angle - 1)) +
          D
</PRE>
For NOAA-14 the following McClain coefficients are used in the MCSST
Split Equation, as specified in the NOAA Polar Orbiter Data User's
Guide page E-33:
<P>
<PRE>
                        A       B        C        D
 Day coefficients:   2.139588 1.017342 0.779706 -278.43
 Night coefficients: 2.275385 1.029088 0.752567 -282.24
</PRE>
For NOAA-12 the following McClain coefficients are used in the MCSST
Split Equation, as specified in the NOAA Polar Orbiter Data User's
Guide page E-31.
<P>
<PRE>
                        A       B        C        D
 Day coefficients:   2.579211 0.963563 0.242598 -263.006
 Night coefficients: 2.384376 0.967077 0.480788 -263.94
</PRE>
For NOAA-9 data the first 3 McClain coefficients are multipliers for
the temperature values of AVHRR channels 3, 4, and 5. Note that the
3 input temperatures are expressed in degrees Kelvin, whereas the
output temperature is in degrees Celsius (NOAA Polar Orbiter Data
User's Guide, page E-11).
<P>
<PRE>
                       A     B       C      D
 Day coefficients:     0, 3.6569, -2.6705,-268.92 
 Night coefficients:   0, 3.6836, -2.69,  -270.42
</PRE>
NOAA-9 Window Split equation:
<P>
<PRE>
         Temperature = A * Temperature (Kelvin) of Channel 3 +
         (Celsius)     B * Temperature (Kelvin) of Channel 4 + 
                       C * Temperature (Kelvin) of Channel 5 + 
                       D
</PRE>
For NOAA-9, it is possible to exclude a channel from the
calculations (for example, if the channel is noisy) by setting the
corresponding McClain coefficient to zero.<p>
By default, McClain coefficients are extracted from the satellite
sensor file (specified by the SENSFILE parameter) but can be
overwritten by the user.
<P>
<PRE>
 EASI&gt;MCCLAIN=a,b,c,d
 EASI&gt;MCCLAIN=          | Use default values extracted from SENSFILE
</PRE>
The McClain coefficients vary slightly according to ocean location
and for large inland water bodies; however the default values are
valid for almost all ocean bodies. Other McClain coefficient values
can be obtained from various research papers.
<P>
<H4>REPORT</H4>
Specifies the file to which to append the generated report.
<P>
<PRE>
 EASI&gt;REPORT=&quot;filename&quot;
 EASI&gt;REPORT=           | defaults to terminal output
</PRE>
The following names have special meaning:
<P>
<PRE>
 EASI&gt;REPORT=&quot;TERM&quot;     | generates a report on your terminal
 EASI&gt;REPORT=&quot;OFF&quot;      | cancels report generation
</PRE>
<hr>
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