|
||||||
|
|
||||||
The content for this page was created by the IDL library routine mk_html_help. For more information on this routine, refer to the IDL Online Help Navigator or type the following at the IDL command prompt:
IDL> ? mk_html_help
NAME:
COLORBAR
PURPOSE:
The purpose of this routine is to add a color bar to the current
graphics window.
CATEGORY:
Graphics, Widgets.
CALLING SEQUENCE:
COLORBAR
INPUTS:
None.
KEYWORD PARAMETERS:
BOTTOM: The lowest color index of the colors to be loaded in
the bar.
CHARSIZE: The character size of the color bar annotations. Default is 1.0.
COLOR: The color index of the bar outline and characters. Default
is ncolors - 1 + bottom.
DIVISIONS: The number of divisions to divide the bar into. There will
be (divisions + 1) annotations. The default is 2.
FORMAT: The format of the bar annotations. Default is '(F6.2)'.
MAX: The maximum data value for the bar annotation. Default is
NCOLORS-1.
MIN: The minimum data value for the bar annotation. Default is 0.
NCOLORS: This is the number of colors in the color bar.
POSITION: A four-element array of normalized coordinates in the same
form as the POSITION keyword on a plot. Default is
[0.88, 0.15, 0.95, 0.95] for a vertical bar and
[0.15, 0.88, 0.95, 0.95] for a horizontal bar.
PSCOLOR: This keyword is only applied if the output is being sent to
a PostScript file. It indicates that the PostScript device
is configured for color output. If this keyword is set, then
the annotation is drawn in the color specified by the COLOR
keyword. If the keyword is not set, the annotation is drawn
in the color specified by the !P.COLOR system variable
(usually this will be the color black). In general, this
gives better looking output on non-color or gray-scale
printers. If you are not specifically setting the annotation
color (with the COLOR keyword), it will probably
be better NOT to set this keyword either, even if you
are outputting to a color PostScript printer.
RIGHT: This puts the labels on the right-hand side of a vertical
color bar. It applies only to vertical color bars.
TITLE: This is title for the color bar. The default is to have
no title.
TOP: This puts the labels on top of the bar rather than under it.
The keyword only applies if a horizontal color bar is rendered.
VERTICAL: Setting this keyword give a vertical color bar. The default
is a horizontal color bar.
COMMON BLOCKS:
None.
SIDE EFFECTS:
Color bar is drawn in the current graphics window.
RESTRICTIONS:
The number of colors available on the display device (not the
PostScript device) is used unless the NCOLORS keyword is used.
EXAMPLE:
To display a horizontal color bar above a contour plot, type:
LOADCT, 5, NCOLORS=100
CONTOUR, DIST(31,41), POSITION=[0.15, 0.15, 0.95, 0.75], $
C_COLORS=INDGEN(25)*4, NLEVELS=25
COLORBAR, NCOLORS=100
MODIFICATION HISTORY:
Written by: David Fanning, 10 JUNE 96.
10/27/96: Added the ability to send output to PostScript. DWF
11/4/96: Substantially rewritten to go to screen or PostScript
file without having to know much about the PostScript device
or even what the current graphics device is. DWF
1/27/97: Added the RIGHT and TOP keywords. Also modified the
way the TITLE keyword works. DWF
7/15/97: Fixed a problem some machines have with plots that have
no valid data range in them. DWF
(See colorbar.pro in your IDL TOVS Path-P tools directory.)
NAME:
ease_convert
PURPOSE:
Use a spherical earth model to convert geographic coordinates to
azimuthal equal-area or equal-area cylindrical grid coordinates
for various EASE-Grids.
CATEGORY:
Grid coordinate conversion
CALLING SEQUENCE:
status = ease_convert ( grid, lat, lon, r, s)
INPUTS:
grid: projection name
SSM/I Polar Pathfinder: [NSM][lh]
(where l="low" res (25km), h="high" res (12.5km))
AVHRR Polar Pathfinder: [NS]a{1,5,25}
(where 1=1.25 km res, 5=5 km res, 25=25 km res)
TOVS-P Polar Pathfinder: NpathP (100km res)
AARI sea ice: AARI (12.5 km res)
lat, lon - geo. coords. (decimal degrees)
OUTPUTS:
r, s - column, row coordinates
RESULT:
status = 0 indicates normal successful completion
-1 indicates error status (point not on grid, unknown
projection)
EXAMPLE:
status = ease_convert ('Nl',90.,0.,col,row)
status will be 0, and the returned col, row will be 360.0, 360.0
NOTES:
Please see All About EASE-Grid and Summary of NOAA/NASA Polar Pathfinder Grid Relationships.
(See easeconv.pro n your IDL TOVS Path-P tools directory.)
NAME:
ease_inverse
PURPOSE:
Use a spherical earth model to convert azimuthal equal-area
or equal-area cylindrical grid coordinates to geographic
coordinates for various EASE-Grids
CATEGORY:
Grid coordinate conversion
CALLING SEQUENCE:
status = ease_inverse ( grid, r, s, lat, lon)
INPUTS:
grid: projection name
SSM/I Polar Pathfinder: [NSM][lh]
(where l="low" res (25km), h="high" res (12.5km))
AVHRR Polar Pathfinder: [NS]a{1,5,25}
(where 1=1.25 km res, 5=5 km res, 25=25 km res)
TOVS-P Polar Pathfinder: NpathP (100km res)
AARI sea ice: AARI (12.5 km res)
r, s - column, row coordinates
OUTPUTS:
lat, lon - geo. coords. (decimal degrees)
RESULT:
status = 0 indicates normal successful completion
-1 indicates error status (point not on grid)
EXAMPLE:
status = ease_inverse ('Nl',360.0, 360.0, lat, lon)
status will be 0, and the returned lat, lon will be 90.0, 0.0
(See easeconv.pro in your IDL TOVS Path-P tools directory.)
NAME:
play_gif
PURPOSE:
Play a gif animation using xinteranimate.
CATEGORY:
Graphics animation.
CALLING SEQUENCE:
PLAY_GIF, gif_filename
INPUTS:
gif_filename: the full pathname of the gif animation file.
If gif_filename is not provided, then
PICKFILE is called to allow the user
to select a file interactively.
KEYWORDS:
GROUP: the widget group of caller.
DIR: the initial directory in which to select; the
directory selected from on return.
FIRST: the first frame number of the animation to play.
The default is 0.
COUNT: the number of frames to play; the default is 50;
0 means play all the frames remaining in the file
after FIRST.
NOREMAP: don't remap palette even if !D.N_COLORS is less
than 256.
RESTRICTIONS:
This procedure requires IDL 5 or higher because it uses
the /MULTIPLE keyword to READ_GIF which wasn't introduced until
IDL 5.
SIDE EFFECTS:
PICKFILE is called if no gif_filename is provided.
If !D.N_COLORS is less than or equal to 256 and noremap is
not set, then a dummy window is opened temporarily to set
the "true" value of !D.N_COLORS, which is then copied to
n_colors, and then the window is deleted.
If !D.N_COLORS LT 256 and noremap is not set, then the palette
is remapped to consist of !D.N_COLORS colors.
XINTERANIMATE is called to display the animation.
EXAMPLE:
To display the first 50 frames of the gif animation file
nor_14_bcktmp_animation.gif, type:
PLAY_GIF, 'nor_14_bcktmp_animation.gif'
To display 35 frames starting at frame number 100 of the gif
animation file bar_14_albd_animation.gif without remapping of
the palette in an 8-bit color environment, type:
PLAY_GIF, 'bar_14_albd_animation.gif', FIRST=100, COUNT=35, $
/NOREMAP
(playgif.pro in your IDL TOVS Path-P tools directory.)
NAME:
PPPU_ADD_SDS
PURPOSE:
Adds a new SDS_INFO structure to the array of structures so far.
CALLING SEQUENCE:
pppu_add_sds, num_sds, sds_descriptions, name, label, unit,
layer_num, fill_value, calibration_factor,
uncalibrated_offset
INPUTS:
num_sds: the current number of SDS descriptions
sds_descriptions: the array of SDS_INFO descriptions
name: the string name of the new SDS
label: the string label of the new SDS
unit: the string unit of the new SDS
layer_num: the integer layer number of the new SDS
This is usually 0, but may be positive if/when the
SDS is actually stored as a 3-D array in the HDF file
fill_value: the SDS fill_value
calibration_factor: the SDS calibration factor
uncalibrated_offset: the SDS uncalibrated offset
OUTPUTS:
num_sds: the incremented number of SDS descriptions
sds_descriptions: the array of SDS_INFO descriptions, with
a new SDS_INFO structure appended to it
(See p3utils.pro in your IDL TOVS Path-P tools directory.)
NAME:
pppu_files
PURPOSE:
Searches directories for a list of P-cube/TOVS files
CATEGORY:
P-cube/TOVS utilities
CALLING SEQUENCE:
list=pppu_files(directory)
INPUTS:
directory: base directory with P-cube/TOVS files. This directory
and 4-digit year subdirectories will be searched for files.
GLOBAL VARIABLES:
platform_index: 1 - use P-cube data
2 - use TOVS Northern Hemisphere Path-P Daily data
3 - use TOVS Northern Hemisphere Path-P Monthly data
4 - use TOVS Southern Hemisphere Path-P Daily data
KEYWORDS:
ANCILLARY: set this keyword to return the name of the ancillary
data file
COUNT: number of files found.
DATES: list of dates to find daily files for. Default is all
files in year subdirectories. (ignored if ANCILLARY is set)
END_DATE: if entered, the date to stop extracting.
Default is end of all P-cube/TOVS files found.
(ignored if ANCILLARY is set)
LABELS: string array of dates of the files found and extracted
from
START_DATE: if entered, the date to start extracting.
Default is beginning of all P-cube/TOVS files found.
(ignored if ANCILLARY is set)
RESULT:
A sorted list of files found, or -1 if none were found.
EXAMPLE:
list=pppu_files('.')
Returns a sorted list of all P-cube/TOVS files found in 4-digit year
subdirectories of ./
NOTES:
P-cube/TOVS files are HDF files with the following characteristics:
1) All files are assumed to be in (4-digit) year
subdirectories of the same base directory
2) File naming convention is dir/yyyy/ppp_n100_yyyyddd_daily.v0
for P-cube files and dir/yyyy/tpp_Nss_h100_yyyyddd_daily[monthly].vx for
TOVS files.
3) The date in the filename is assumed to be correct
4) There is exactly 1 file per date
5) All files are assumed to contain the same HDF
structure. It is assumed that they all contain
the same, fixed set of SDSs (Scientific Data Sets)
6) A single ancillary data file will be assumed to be in dir.
(See p3utils.pro in your IDL TOVS Path-P tools directory.)
NAME:
PPPU_GET_SDS_DESCRIPTIONS
PURPOSE:
Retrieve information for all SDS's in this file
CALLING SEQUENCE:
desc = pppu_get_sds_descriptions(filename)
INPUTS:
filename: filename string from which the SDS descriptions
will be retrieved
GLOBAL VARIABLES:
platform_index: 1 - use P-cube data
2 - use TOVS Northern Hemisphere Path-P Daily data
3 - use TOVS Northern Hemisphere Path-P Monthly data
4 - use TOVS Southern Hemisphere Path-P Daily data
KEYWORDS:
COUNT: the number of SDS_INFO records returned
RESULT:
Returns an array of SDS_INFO records, one for each SDS in
this file, or -1 if no records were found.
(See p3utils.pro in your IDL TOVS Path-P tools directory.)
NAME:
PPPU_IS_ANCILLARY_SDS
PURPOSE:
Determine whether sds_name is ancillary data
CALLING SEQUENCE:
status=pppu_is_ancillary_sds(sds_name)
INPUTS:
sds_name: name of sds to examine
RESULT: 1 if sds_name is ancillary data, 0 otherwise
(See p3utils.pro in your IDL TOVS Path-P tools directory.)
NAME:
PPPU_YYYYDOY_TO_JULDAY
PURPOSE:
Convert year, day of year string to Julian day
CALLING SEQUENCE:
status=pppu_yyyydoy_to_julday(yyyydoy)
INPUTS:
yyyydoy: string date
RESULT: the Julian day corresponding to yyyydoy
or -1 in case of error
(See p3utils.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_animate
PURPOSE:
Extracts and animates a time-series array of SDS data of a
given type and list of dates (see NOTES for warning about memory).
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_animate, sds_name
INPUTS:
sds_name: the string SDS name for this data, (will be used
to determine display range, colors, etc)
OUTPUTS:
labels: string array of labels, 1 for each frame of data
KEYWORDS:
DATA: a named variable returned with the requested data array
DATES: integer or string array of dates [yyyydoy,yyyydoy,...]
Default is dates of 1st 10 P-cube/TOVS files found.
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
END_DATE: if entered, the date to stop extracting.
Default is end of all P-cube/TOVS files found.
GRAT_COLOR: set this keyword to a non-zero color index to display the
graticule overlay (Default is no overlay)
LABELS: string array of dates of the files found and extracted
from, used for label in lower left corner of each displayed frame.
MAP_COLOR: set this keyword to a non-zero color index to display the
map overlay (Default is no overlay)
MAX_VALUE: the highest value to display. Default is maximum
non-fill_value
MIN_VALUE: the lowest value to display. Default is minimum
non-fill_value
SDS_INFO: a named variable returned with metadata for the sds_name,
used to determine unit and sds_label to write on the
lower right corner of the display, and fill_value.
START_DATE: if entered, the date to start extracting.
Default is beginning of all P-cube/TOVS files found.
VERBOSE: set for verbose output summary
EXAMPLE:
ppp_animate, 'a_surface_albedo', START_DATE=1988001,
END_DATE=1988020,DATA=data,SDS_INFO=info,LABELS=lab
20 days of surface albedo, will be extracted and animated
via xinteranimate
NOTES:
Warning: this routine is extremely memory-intensive. Calling
it with a large number of dates may result in memory errors.
(See p3animat.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_compare
PURPOSE:
Displays a scatter plot of (scaled) data for two P-cube/TOVS SDS's
for a given date
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_compare, x_sds_name, y_sds_name, date
INPUTS:
x_sds_name: the string SDS name that will be
extracted and displayed on the X-axis; the list of
valid SDS names is returned as the name element of the
sds_description structure from ppp_toc
y_sds_name: the string SDS name that will be
extracted and displayed on the Y-axis; the list of
valid SDS names is returned as the name element of the
sds_description structure from ppp_toc
date: scalar integer (yyyydoy) or string ('yyyydoy') date to
extract and display
KEYWORDS:
CURSOR: set this keyword for interactive cursor behavior
in the display window
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
MISSING: set to display "missing" (aka "fill" values)
Default is only to display values where both are non-missing.
NEW_WINDOW: set this keyword to open a new window for display
VERBOSE: set for verbose output summary
_EXTRA=extra_keywords: This routine is essentially a wrapper
to IDL's plot routine, so any extra keywords entered will
be passed to the plot command
RESULT:
A scatter plot of the results
EXAMPLE:
ppp_compare, 't_temperature-700','t_temperature-850', 1988020,
title='TOVS temperature 700 vs 850 mb',/cursor
A scatter plot of values where both SDS's are non-missing values
will be displayed in the current window. The mouse will be
activated to return data values as it is dragged across the
display plot
NOTES:
(See p3compar.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_extract
PURPOSE:
Extracts an array of SDS data of a given type and list of dates.
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
result = ppp_extract, data, sds_name
INPUTS:
sds_name: the string SDS name that is returned as the name
element of the sds_description structure from ppp_toc
OUTPUTS:
data: the data array for this sds_name extracted from each
file corresponding to dates
KEYWORDS:
DATES: integer or string array of dates [yyyydoy,yyyydoy,...]
Default is dates of all P-cube/TOVS files found.
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
END_DATE: if entered, the date to stop extracting.
Default is end of all P-cube/TOVS files found.
LABELS: string array of dates of the files found and extracted
from
RAW: set this keyword to retrieve raw stored data
Default is to return scaled data
SDS_INFO: a named structure with information about this SDS
includes unit, SDS label, fill value, etc.
START_DATE: if entered, the date to start extracting.
Default is beginning of all P-cube/TOVS files found.
VERBOSE: set for verbose output summary
RESULT:
This function returns 1 on success, or 0 in the event of an error
EXAMPLE:
result = ppp_extract( data,'a_surface_albedo',
dates=[1988001,1988002],labels=labels)
The returned data array will contain 3-D surface albedo
(cols x rows x 2 days).
The returned labels array will be a string array with
the date of each layer found
NOTES:
Dates with no corresponding P-cube/TOVS files are reported and ignored.
(See p3extrct.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_platform
PURPOSE:
Allows user to select either P-cube or TOVS data.
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_platform
INPUT:
RETURN VALUE:
1 - use P-cube data
2 - use TOVS Northern Hemisphere Path-P Daily data
3 - use TOVS Northern Hemisphere Path-P Monthly data
4 - use TOVS Southern Hemisphere Path-P Daily data
NOTES:
(See p3pltfrm.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_plot
PURPOSE:
Displays a plot of data at a given pixel,
for a given SDS and a set of dates
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_plot, sds_name, column, row
INPUTS:
sds_name: the string SDS name that will be extracted and
sliced for display (valid SDS names are returned as
the name element of the sds_description structure from ppp_toc)
column,row: the data coordinates (0..66) to slice and display
KEYWORDS:
CURSOR: set this keyword for interactive cursor behavior
in the display window
DATES: integer or string array of dates [yyyydoy,yyyydoy,...]
Default is dates of all P-cube/TOVS files found.
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
END_DATE: if entered, the date to stop extracting.
Default is end of all P-cube/TOVS files found.
LABELS: string array returned with dates of the files found
and extracted from, these will be used to determine
x-axis coordinates
MISSING: set to include dates with "missing" (aka "fill" values),
treated as NaN (not-a-number) on the plot.
Default is only to display non-missing values
NEW_WINDOW: set this keyword to open a new window for display
RAW: set this keyword to retrieve raw stored data
Default is to get scaled data
SLICE: name of a variable that will be returned with the
data displayed on the y-axis
START_DATE: if entered, the date to start extracting.
Default is beginning of all P-cube/TOVS files found.
VERBOSE: set for verbose output summary
XTICKS: the number of x-axis tick intervals to draw
Default is 4 intervals (5 tick values will be labelled)
_EXTRA=extra_keywords: This routine is essentially a wrapper
to IDL's plot routine, o any extra keywords entered will
be passed to the plot command
RESULT:
Plot of the slice at the input column,row
EXAMPLE:
ppp_plot, 't_temperature-700',10,20,dates=indgen(20)+1988020
title='TOVS temperature 700 at pixel (10,20)',/cursor
The slice of SDS data at column 10, row 20 from the 20 dates
beginning January 20, 1988 will be extracted, and non-missing
values will be plotted. The mouse will be activated to return
data values as it is dragged across the display plot
NOTES:
(See p3plot.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_plot_xparams
PURPOSE:
Use an array of string dates ['yyyydoy'] to set up plot
parameter xvalues, xtickvalues and number of ticks
CATEGORY:
P-cube/TOVS display
CALLING SEQUENCE:
ppp_plot_xparams, strdates, xvals, xtickv, xticks
INPUTS:
strdates: string array with year, day of year strings ['yyyydoy']
for x-axis values
xticks : the number of tick intervals to establish
OUTPUTS:
xvals: returned array with x values (julian dates) to plot
xtickv : returned array with the tick values for xticks+1 labels
EXAMPLE:
dates = strcompress(string(indgen(10)+1988020),/rem)
ppp_plot_xparams, dates, xvals, xtickv, xticks
returned parameters can be used in a subsequent call to plot
(See p3plot.pro in your IDL TOVS Path-P tools directory.)
NAME:
PPP_READ
PURPOSE:
Reads a 2-D array of data from a file
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
result = ppp_read( data, sds_name, filename )
INPUTS:
sds_name: name of the SDS
filename: file to read
OUTPUTS:
data: a 2-D array of sds_name data read from filename
KEYWORDS:
RAW: set this keyword to return raw (unscaled) data
(default is to return scaled data)
SDS_INFO: a named structure returned with information about this SDS
includes unit, SDS label, fill value, etc.
VERBOSE: set for verbose output
RESULT:
1 on success, 0 otherwise
EXAMPLE:
filename = '/usr4/data/pcube/1988/ppp_n100_1988352_daily.v0.5.hdf'
result = ppp_read(data,'a_surface_albedo', filename,SDS=info)
The returned data array will contain scaled surface albedo data
from the Pcube file for day 352 of 1988
The returned info structure will contain SDS-specific
information for these data (name, label, units, fill_value,
etc)
(See p3read.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_restore
PURPOSE:
Restores an array of extracted SDS data and accompanying metadata
CATEGORY:
P-cube/TOVS data tools
CALLING SEQUENCE:
ppp_restore, data, labels, sds_info, filename
INPUTS:
filename: the filename to create and write to
OUTPUTS:
data: a 2- or 3-D data array
labels: string array of labels for each layer of data;
the number of labels will match the size of data's
3rd dimension (or be 1 if data is a single layer)
sds_info: a named structure with information about this
data, includes name, units, SDS label, fill value, etc.
KEYWORDS:
VERBOSE: set for verbose output summary
EXAMPLE:
status = ppp_extract (data,'a_surface_albedo',start_date=1988001,
end_date=1988031,labels=labels,sds_info=info)
if 1 eq status then ppp_save, data, labels, info,
'surf_albedo.dat',/verbose
(in a later session:)
ppp_restore, data, labels, info, 'surf_albedo.dat',/verbose
The returned data, labels, and info variables will contain
saved values from the earlier session
(See p3restor.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_save
PURPOSE:
Saves an array of extracted SDS data and accompanying metadata
CATEGORY:
P-cube/TOVS data tools
CALLING SEQUENCE:
ppp_save, data, labels, sds_info, filename
INPUTS:
data: the 2- or 3-D data array extracted via ppp_extract
labels: string array of labels for each layer of data;
the number of labels must match the size of data's
3rd dimension (or be 1 if data is a single layer)
sds_info: a named structure with information about this SDS
returned from sds_extract, includes unit, SDS label,
fill value, etc.
filename: the filename to create and write to
KEYWORDS:
VERBOSE: set for verbose output summary
EXAMPLE:
status = ppp_extract (data,'a_surface_albedo',start_date=1988001,
end_date=1988031,labels=labels,sds_info=info)
if 1 eq status then ppp_save, data, labels, info,
'surf_albedo.dat',/verbose
The extracted data array and metadata will be saved to the
file 'surf_albedo.dat', and can be restored via ppp_restore
(See p3save.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_show
PURPOSE:
Reads and displays a grid of P-cube/TOVS SDS data for a given date
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_show, sds_name
INPUTS:
sds_name: the string SDS name that is returned as the name
element of the sds_description structure from ppp_toc
OUTPUTS:
KEYWORDS:
CURSOR: set this keyword for interactive cursor behavior
in the display window
DATA: a named variable returned with the requested data layer
DATE: integer or string date of daily file to read
(yyyydoy or 'yyyydoy'). This keyword is ignored for
ancillary sds_name's. Default is 1988001.
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
GRAT_COLOR: set this keyword to a non-zero color index to display the
graticule overlay (Default is no overlay)
IMAGE: an 8-bit image of the displayed window
LABEL: string to write to the lower left corner of the display
Default is the date as mm-dd-yyyy
LEGEND_TITLE: string to write as a legend title
Default is the units from the file's sds_info
MAP_COLOR: set this keyword to a non-zero color index to display the
map overlay (Default is no overlay)
MIN_VALUE,MAX_VALUE: the min/max data values to display
(values in this range will be scaled linearly)
Default is min/max of non-fill_value data.
MULTIPLY: multiplication factor for resampled output. Default is 10.
NEW_WINDOW: set this keyword to open a new window for display
if NEW_WINDOW = -1 then do not display data'
SDS_INFO: a named variable returne with metadata for the sds_name,
will be used to determine unit and sds_label to write on the
lower right corner of the display, and fill_value.
SDS_LABEL: string to write to the lower right corner of the display
Default is the sds label from the file's sds_info
VERBOSE: set for verbose output summary
RESULT:
A window will be presented with the data scaled appropriately
for the type of data.
EXAMPLE:
sds_name='a_surface_albedo'
ppp_show, sds_name, DATE=1988020, DATA=data, IMAGE=image, $
sds_info=sds_info, map=196, grat=196,/cursor
data will contain a 67x67 fltarr with AVHRR surface albedo values.
sds_info will contain sds metadata for AVHRR surface albedo.
NOTES:
(See p3show.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_stats
PURPOSE:
Prints summary statistics (min, max, fill_value, % missing, non-missing
avg and standard deviation) for SDS data for a list of dates.
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_stats, sds_name
INPUTS:
sds_name: the string SDS name that is returned as the name
element of the sds_description structure from ppp_toc
KEYWORDS:
DATES: integer or string array of dates [yyyydoy,yyyydoy,...]
Default is dates of all P-cube/TOVS files found.
This parameter is ignored for ancillary data SDSs.
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
END_DATE: if entered, the date to stop extracting.
Default is end of all P-cube/TOVS files found.
This parameter is ignored for ancillary data SDSs.
GLOBAL_STATS: an anonymous structure with global values
of displayed statistics for all dates found
LUN: file unit to write output to. Default is -1 (stdout)
START_DATE: if entered, the date to start extracting.
Default is beginning of all P-cube/TOVS files found.
This parameter is ignored for ancillary data SDSs.
EXAMPLE:
ppp_stats, 'a_surface_albedo',dates=[1988001,1988002]
Summary statistics for Jan. 1 and 2, 1988 AVHRR surface albedo
will be printed.
NOTES:
Dates with no corresponding P-cube/TOVS files are reported and ignored.
(See p3stats.pro in your IDL TOVS Path-P tools directory.)
NAME:
ppp_toc
PURPOSE:
Prints a table of contents of data from P-cube or TOVS HDF files.
"P-cube" was coined to refer to combined data from the three Polar
Pathfinder data sets (Polar AVHRR, TOVS Path-P, and SSM/I). It is
also a pun on the data structure, which is essentially a hypercube of
gridded data with dimensions cols x rows x parameters x time.
CATEGORY:
HDF Interface to P-cube/TOVS data files
CALLING SEQUENCE:
ppp_toc, sds_descriptions, dates
OUTPUTS:
sds_descriptions: variable that is returned with an array
of SDS_INFO structures, one for each SDS in these P-cube/TOVS files.
dates: variable that is returned with a string array of the
dates of the available data, as 4-digit year and day of year
(yyyydoy)
GLOBAL VARIABLES:
platform_index: 1 - use P-cube data
2 - use TOVS Northern Hemisphere Path-P Daily data
3 - use TOVS Northern Hemisphere Path-P Monthly data
4 - use TOVS Southern Hemisphere Path-P Daily data
KEYWORDS:
DIRECTORY: base directory with P-cube/TOVS files. 4-digit year
subdirectories will be searched for P-cube/TOVS files.
Default is ./
VERBOSE: set for verbose output summary
EXAMPLE:
ppp_toc, SDS_DESC, sds_descriptions, DATES=dates, DIR='/CDROM/PCUBE/DATA/'
The sds_descriptions and dates for files in '/CDROM/PCUBE/DATA/'
year subdirectories will be returned. A summary will be displayed.
(See p3toc.pro in your IDL TOVS Path-P tools directory.)
NAME:
ssmi_convert
PURPOSE:
Use a spherical earth model to convert geographic coordinates to
azimuthal equal-area or equal-area cylindrical grid coordinates
(for SSM/I EASE-Grids, 25 km, 12.5 km)
CATEGORY:
Grid coordinate conversion
CALLING SEQUENCE:
status = ssmi_convert ( grid, lat, lon, r, s)
INPUTS:
grid: projection name '[NSM][lh]'
(where l="low" res (25km), h="high" res (12.5km)
lat, lon - geo. coords. (decimal degrees)
OUTPUTS:
r, s - column, row coordinates
RESULT:
status = 0 indicates normal successful completion
-1 indicates error status (point not on grid)
EXAMPLE:
status = ssmi_convert ('Nl',90.,0.,col,row)
status will be 0, and the returned col, row will be 360.0, 360.0
(See easeconv.pro in your IDL TOVS Path-P tools directory.)
NAME:
ssmi_inverse
PURPOSE:
Use a spherical earth model to convert azimuthal equal-area
equal-area cylindrical grid coordinates to geographic coordinates
(for SSM/I EASE-Grids, 25 km, 12.5 km)
CATEGORY:
Grid coordinate conversion
CALLING SEQUENCE:
status = ssmi_inverse ( grid, r, s, lat, lon)
INPUTS:
grid: projection name '[NSM][lh]'
(where l="low" res (25km), h="high" res (12.5km)
r, s - column, row coordinates
OUTPUTS:
lat, lon - geo. coords. (decimal degrees)
RESULT:
status = 0 indicates normal successful completion
-1 indicates error status (point not on grid)
EXAMPLE:
status = ssmi_inverse ('Nl',360.0, 360.0, lat, lon)
status will be 0, and the returned lat, lon will be 90.0, 0.0
(See easeconv.pro in your IDL TOVS Path-P tools directory.)
TOVS Path-P data users will need to look in the directory where the IDL tools were installed from the NSIDC TOVS Path-P FTP site. If the tools are not already installed, see the Getting Started section of this tutorial for installation instructions.