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smigen

Description: This program reads in a Level-3 space-binned or time-binned file and generates a Standard Mapped Image (SMI) HDF product containing one of 5 possible statistical measures. SMI products are image representations of binned data products. This image is a two-dimensional array of an Equidistant Cylindrical projection of the globe. The resolution of the default 9km grid is approximately 0.08789 degrees and a global SMI product is 4096x2048 pixels. Each SMI product contains one image of a geophysical parameter and is stored in one physical HDF file.

This HDF file contains:

  1. a byte-valued or int16-valued HDF SD in global Equidistant Cylindrical projection
  2. global file attributes
  3. a color palette

Byte and int16 SD values can be converted back to geophysical values by using the global attributes Scaling, Scaling Equation, Base, Slope and Intercept, where Scaling Equation will be one of:

The SMI default data value format is 8-bit integer, lacking the full precision of the original retrieval. Also, the SMI format presents the data in an equirectangilar grid, which means the spatial resolution varies with latitude. In contrast, the binned products maintain the data in an equal-area projection. Generally speaking, it is recommended that you use the binned products when doing detailed, quantitative analysis, and you use the SMI products when you just want easy access to a global image.

[Command Mode][Interactive Mode]


Command Mode:

Usage:  smigen, ifile="ifile", prod_name="prod_name", projection=projection, resolution=resolution, precision=precision, latnorth=latnorth, latsouth=latsouth, lonwest=lonwest, loneast=loneast, stat=stat, stype=stype, range=range, palette=palette, ofile=ofile, nosubmit=nosubmit, help=help

Minimum command:  smigen, ifile="ifile", prod_name="prod_name"

Examples:  Note that to specify multiple products, you may either run smigen several times in succession, or specify several products at once. If you specify several products at once, and wish to override the product defaults, all arguments will accept arrays of values (see example 2 below).

   (1) smigen, ifile="l3b.hdf", prod_name="chlor_a",stype='lin'

   (2) smigen, ifile="l3b.hdf", prod_name=["chlor_a","sst"],precision=["B","I"]


Arguments/Keywords:
ifile Input Level-3 binned HDF file. (Required)
prod_name  Geo-Physical product name(s). See the list below. (Required)
projection Output projection type.  SIN or RECT (Default='RECT').
resolution Output resolution.  SMI, SMI4, LAND, 36km, 9km, 4km, 2km, or 1km.   (Default='9km')
precision Output datatype.  B=Byte (8-bit int), I=Integer (16-bit int).  (Default=B)
latnorth Northernmost latitude used for output.  (Default=90.0)
latsouth Southernmost latitude used for output.  (Default=-90.0)
lonwest Westernmost longitude used for output.  (Default=-180.0)
loneast Easternmost longitude used for output.  (Default=180.0)
stat Measure to calculate.  The following variables are stored for every bin in the L3-binned input file and are used in calculating the measures:
s = sums of all values input to the bin
ssq = sums of the squares of all input values to the bin
wt = weight assigned to that bin
ns = number of scenes input to that bin
stat value Measure calculated Defined at a given bin as:
1 Mean(Default) s/wt
2 Variance tmp_var = (ssq/wt)-(mean**2)
var = (tmp_var * wt**2) / ((wt**2)-ns)
3 Standard Deviation sqrt(var)
4 Pixels number of Level-2 input values that went into creating the Level-3 bin selected for each grid point
5 Scenes number of Level-2 input files that went into creating the Level-3 bin selected for each grid point
stype Scaling type to use: 'lin'=Linear, 'log'=Log. (See defaults below).
range Data range for scaling : [dmin, dmax]. (See defaults below).
palette Name of ASCII color palette. (Default is the SMI chlor or sst color palette).
ofile Output file name. (Default is to automatically generate output file name.)
help Print command usage to screen.
nosubmit Do not submit commands, just print them.

Product Names and Scaling Defaults
(Note that minimum data values correspond to byte=0, int16=0 and maximum data values correspond to byte=250, int16=65534.)
Product Data min Data max Slope for BYTE Slope for INT16 Intercept Scaling
nLw_4120.05.080.020327.75170e-50.0Linear
nLw_4430.03.810.015245.81378e-50.0Linear
nLw_4880.02.540.010163.87585e-50.0Linear
nLw_4900.02.540.010163.87585e-50.0Linear
nLw_5100.02.540.010163.87585e-50.0Linear
nLw_5200.05.080.020327.75170e-50.0Linear
nLw_5310.01.270.005081.93793e-50.0Linear
nLw_5500.01.270.005081.93793e-50.0Linear
nLw_5510.01.270.005081.93793e-50.0Linear
nLw_5550.01.270.005081.93793e-50.0Linear
nLw_5650.05.080.020327.75170e-50.0Linear
nLw_6670.01.0160.0040641.55034e-50.0Linear
nLw_6700.01.0160.0040641.55034e-50.0Linear
chlor_a0.0164.56540.0152405.81378e-5-2.0Log
chlor_oc20.0164.56540.0152405.81378e-5-2.0Log
chlor_oc30.0164.56540.0152405.81378e-5-2.0Log
chlor_oc40.0164.56540.0152405.81378e-5-2.0Log
chlor_ndpi0.0164.56540.0152405.81378e-5-2.0Log
chlor_clark0.0164.56540.0152405.81378e-5-2.0Log
chlor_carder0.0164.56540.0152405.81378e-5-2.0Log
chlor_gsm010.0164.56540.0152405.81378e-5-2.0Log
K_4900.016.2230.0111764.26344e-5-2.0Log
sst-2.045.00.1887.17185e-4-2.0Linear
sst4-2.045.00.1887.17185e-4-2.0Linear
par0.076.20.30481.16275e-30.0Linear
calcite5.01187e-50.05597570.0121924.65102e-5-4.3Log
calcite_2b5.01187e-50.05597570.0121924.65102e-5-4.3Log
calcite_3b5.01187e-50.05597570.0121924.65102e-5-4.3Log
flh0.0010.1076470.00812803.10068e-5-3.0Log
ndvi-0.350.920.005081.93793e-5-0.35Linear
evi-0.350.920.005081.93793e-5-0.35Linear
eps_780.851.2310.0015245.81378e-50.85Linear
angstrom_510-0.11.47480.00629922.40303e-5-0.1Linear
angstrom_520-0.11.47480.00629922.40303e-5-0.1Linear
angstrom_531-0.11.47480.00629922.40303e-5-0.1Linear
tau_6700.00.5080.0020327.75170e-50.0Linear
tau_8650.00.5080.0020327.75170e-50.0Linear
tau_8690.00.5080.0020327.75170e-50.0Linear
taua_8650.00.5080.0020327.75170e-50.0Linear
taua_8690.00.5080.0020327.75170e-50.0Linear


Interactive Mode:

Main SMI Widget:

The main SMI widget can be accessed under then main SeaDAS Process pull down menu or from the seadas command line by typing "smigen".

Input File Selection Section:
Level-3 binned file  The input Level-3 binned file.  It can be either a space-binned or time-binned file. This entry can be typed in manually or interactively selected with the Select button.
Select To interactively select an input file using the File Selection Widget. The file selected will be displayed in the Level-3 binned file input field.
Help Display this HTML help file in local Netscape or Mosaic HTML viewer.
Quit Quit the smigen GUI.

Current Working Product Entry Section: In this section, SMI output products are defined. The user can change all the output parameters such as product, latnorth, latsouth, lonwest, loneast, projection, resolution, measure, scaling and output filename until a desired output product is defined. Once an output product is defined, pressing the Add to Process List button adds the current product to the list for processing. As many output products can be added to the process list as desired. In addition, once an item has been added to the process list, it can be edited further by selecting the item with the left mouse button, modifying the information and then pressing the Update Process List button.

Products The current working geo-physical parameter. When a product button is selected, the defaults for Measure and Scaling for that product are automatically loaded.  A default output file name is also automatically generated. (See Command Mode for a list of the scaling defaults.)
Latnorth Northernmost latitude used for output.  (Default=90.0)
Latsouth Southernmost latitude used for output.  (Default=-90.0)
Lonwest Westernmost longitude used for output.  (Default=-180.0)
Loneast Easternmost longitude used for output.  (Default=180.0)
Projection Output projection type.  SIN or RECT  (Default=RECT).
Resolution Output resolution.  SMI, SMI4, LAND, 36km, 9km, 4km, 2km, or 1km.   (Default=9km)
Precision Output datatype.  BYTE (8-bit int), INT16 (16-bit int).  (Default=BYTE)
Measure The statistical measure desired for the geo-physical parameter selected.  Note that measures pixels and scenes will produce exactly the same output across all geo-physical parameters for a given input file.  The following variables are stored for every bin in the L3-binned input file and are used in calculating the measures:
s = sums of all values input to the bin
ssq = sums of the squares of all input values to the bin
wt = weight assigned to that bin
ns = number of scenes input to that bin
Mean s/wt
Variance tmp_var = (ssq/wt)-(mean**2)
var = (tmp_var * wt**2) / ((wt**2)-ns)
Standard Deviation sqrt(var)
Pixels Number of Level-2 input values that went into creating the Level-3 bin selected for each grid point
Scenes Number of Level-2 input files that went into creating the Level-3 bin selected for each grid point
Scaling The inputs to use for scaling the geo-physical product.  Modifying any of the scaling parameters will cause the others to automatically recalculate. ***NOTE: You must hit the enter key after entering these values!***  (See Command Mode for a list of the scaling defaults).
File Out The name of the SMI HDF output file. (One output file per geo-physical product).
ASCII Palette File The name of an alternate color palette to use instead of the default color table. (A blank denotes using the SMI default color palette).
Add To Process List Add the current working product entry to the processing list.
Update Process List  Update the highlighted item in the processing list with the current information in the working product entry.

Products Selected For SMI Processing Section:

Products Selected List  Selecting an item in the processing list, will cause all the fields to be loaded back into the working product entry.
Delete Entry Delete the highlighted item in the processing list.
Clear All Delete all items from the processing list.

Job Submission Section:

Submit Submit all items in the processing list for SMI processing in the background. Output messages will be printed to the specified Log File. If the log file entry is left blank, messages will print to the screen.
Run Process all items listed in the processing list in the foreground. All output messages will be printed to the terminal screen. This option will tie up your terminal and may take several minutes depending on the number of bins in the input file.  It is not advisable to use this option.
Log File  The name of the logfile for smigen job submission. If blank, any log information will be printed to the screen.


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Authorized by: gene carl feldman

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Updated: 10 November 2008