Scenarios
How
to display a SeaWiFS product with coastlines and gridlines?
-
Start up the general display
program 'seadisp' main menu:
-
From Seadas Main Menu,
select Display->seadisp
-
Load a SeaWiFS product:
-
From Seadisp Main Menu,
select menu item Load -> SeaWiFS.
-
Enter or use the Select
button to pick any SeaWiFS product file name.
-
Press the Okay button
or simply <RETURN> to view all available products in the file.
-
Select the product to be loaded
and press the Load button. After the product loaded, you will
see it is added to the Band List Widget.
-
Display the SeaWiFS product:
-
From the Band List Widget,
select the product you would like to display.
-
Select the window number for
display.
-
Press the Display button
to display the product on the Display Window Widget.
-
Display the coastlines and gridlines:
-
From the Display Window
Widget, select Functions ->Coastline
to display the coastlines.
-
From the Display Window
Widget, select Functions ->Grid
to display the gridlines.
-
To modify the default setups
for coastline and gridline functions, from the Display Window Widget
select Setups->Coastline or Setups->Grid.
How
to rescale an image?
-
Load and display any product
in a display window.
-
Open the rescale setup by selecting
Setups->Rescale
from the Display Window Widget.
-
After modifying the Scale Min/Max
and/or the Scale Type, press Redisplay.
-
If you would like to see a histogram
of your image to aid you in rescaling it, select the display menu item
Functions->Histogram.
-
If some of the text on your
histogram plot window is smashed together, you can resize the window.
-
Use the histogram plot results
to aid you in entering in better rescaling values in the Display
Scaling Setup Widget.
How
to display SeaWiFS L1A, L1B, and L2 data at the same location?
-
Load all products to be examined
into the Band List Selection Widget.
-
Select and display at least
one product from the Band List Selection Widget to display
windows for cursor manipulation.
-
From Seadisp Main Menu->Functions,
select the menu item Multiple Bands Data Display.
-
Turn off any products you are
not interested in by pressing the toggle button on the left of the product
name.
-
Move the cursor in any display
window.
-
The raw and geophysical data
values, pixel/line values and lat/lon coordinates will be displayed for
all selected bands at the cursor location.
How
to examine the image data around a specified location?
-
Load and display the image to
be examined to a display window. The image must have SeaDAS recognized
navigation information.
-
From the Display Window
Widget->Functions, select
Read & Profile.
-
From the Read Main Window
widget, drag the mouse left button inside the small dark window to move
the software cursor to any location in the displayed image, OR, to move
the software cursor to a specified lat/lon or pixel/line location, in the
displayed image:
-
Enter in the desired lat/lon
in the Lat/Lon fields or pixel/line values in the Pixel/Line
fields.
-
Press either Move to pixel/line
or
Move
to lat/lon, to move the software cursor in the image display window
to the specified location.
-
To examine the data values and
statistics for a small region around the cursor:
-
Select a Box size for
the pixels to be covered for output.
-
Press Output box data,
to display all the pixel values inside the specified box size region with
the statistics.
How
to display image profiles?
-
Load and display the image for
profile plot to a display window.
-
From the Display Window
Widget->Functions, select Read & Profile.
-
From the Read Main Window
widget, drag the left mouse button inside the small dark window to move
the software cursor to any location in the displayed image, OR, to move
the software cursor to a specified lat/lon or pixel/line location, in the
displayed image:
-
Enter in the desired lat/lon
in the Lat/Lon fields or pixel/line values in the Pixel/Line
fields.
-
Press either Move to pixel/line
or
Move
to lat/lon, to move the software cursor in the image display window
to the specified location.
-
To plot a row or column profile
on the software cursor position:
-
Press Plot row profile or
Plot
column profile to generate the profile plot.
-
To turn on the interactive profile
plot mode or to change the default setups for profile plot, you can press
Profile
plot setup.
How
to display two images with two different color tables?
-
Load the two images into the
Band
List Selection widget.
-
From the Band List Selection
widget,
select LUT no.: 1 and
Window: 1 to display the first image
and select LUT no.:2. and Window: 2 to display the second
image.
-
To load separate color tables
into each of these windows:
-
Click on Seadisp Main
Menu Widget->Functions->Color LUT->Load Color or Display
Window Widget->Functions->Color LUT->Load Color.
-
Select the Color table
number 1 and then load a color table.
-
The image loaded using color
table 1 should change color.
-
Select Color table number
2 and then load a different color table.
-
The image loaded using color
table 2 should now change color.
To change the number of pre-allocated
color tables or change the partition sizes:
-
From Seadisp Main Menu->Global
Setup, select the menu item
Change Color Table Configuration.
-
Notice the Full session range
values. This shows you how many colors you have available in your
current session for coloring data (the graphics palette and other colors
are excluded from this number).
-
To change the number of concurrent
color tables, select a number from No. of concurrent tables menu.
If you don't like the calculated default partitions, you can change the
partition range values. When you are satisfied with the new partitions,
press Apply.
If you have the Load Color
Widget up, you should be able to see the color table repartition and
rescale. Any currently displayed windows will rescale and redisplay
and should look the same as before the repartitioning.
How
to add graphics annotation and save the results to a PNG or PS file?
-
Load and display the image for
annotation and output to a display window.
-
To put annotation on the image:
-
From the Display Window
Widget, select Functions->Annotate/Blotch->Main Window.
-
To put text on your image:
-
Specify a text object by selecting
the Abc button
-
Enter your annotation in the
entry labelled 'Text :'
-
Place the object initially by
clicking the left mouse button in your image window.
-
To move the object, drag the
text around with the left mouse button to place it by positioning the mouse
over the center positioning box OR
-
Stretch or rotate the text by
either:
-
Dragging one of the end positioning
boxes OR
-
Using the size and orientation
widgets
-
Change the font and the
color
-
To save a graphics object, click
the right mouse button or press Save.
-
To re-edit an object:
-
Change mode from Draw
to Select
-
Click on the object you want
to re-activate
-
Make any attribute changes and
remember to save the object.
-
To delete an object:
-
Select the object
-
Instead of saving it, click
on another graphics object type
-
To exit the annotation
widget:
-
Select File ->Exit.
-
To output the image with the
annotation to a PNG or PS file:
-
From the Display Window
Widget, select Functions->Output->Display.
-
From the Output Setup
Widget:
-
Select Type->Image Display
-
A meaningful output file name
will be automatically generated if the Output File Name field is
left blank.
-
Select window and region
to be output
-
Select whether to output a Postscript
or PNG file
-
If postscript is selected, the
xsize,
ysize, xoffset, yoffset values are automatically calculated
to center the image on the page. It is never necessary to modify
these values unless centering is undesired.
-
Press the Go button to
write the file.
How
to display and mask the SeaWiFS, MODIS, or OCTS L2 products with flags?
-
Make sure that the L2 flags
data is loaded and listed in the Band List Selection widget
and the corresponding L2 product to be applied is loaded and displayed
in a display window.
-
From the Seadisp Main
Menu, select the Functions->L2 Flags Display menu
item to display the main widget for this function.
-
On the L2 Flags Display
widget, select the band number from the Band List Selection
widget that the L2 flags data is loaded to.
-
Select the display window number
that the L2 product is displayed and where the flags will be applied.
-
Change the Flag type
to the appropriate SeaWiFS, MODIS, or OCTS L2 Flags setting.
-
To select and display a single
flag:
-
Select the flag to be displayed
using the One Flag slide bar or just click the flag toggle button.
-
Click the Load button
and all the pixels in the display window with that flag set will be displayed
with the color assigned to that flag. The color assigned to each flag may
be changed using Modify flags' colors option under the Flag Function
Menu.
-
To select and display multiple
flags at once:
-
To add or remove a flag from
the Multiple Flags list, just click the toggle button of that flag.
The flag will be inserted in the beginning of the list, if it is not in
the list, otherwise, it will be removed from the list.
-
Click the Load button
and all the pixels in the display window with those flags set will be displayed
with the colors assigned to those flags. The priority order for flags
on the same pixel is from left to right (low to high) of the flag list.
The color assigned to each flag may be changed using Modify flags' colors
option under the Flag Function Menu.
-
More functions from the drop
down Flag Function Menu:
-
Load one flag - To display
the flag specified in the One Flag field with its assigned color
on top of the selected display window.
-
Load multiple flags -
To display the flags specified in the Multiple Flags field with
their assigned colors on top of the selected display window.
-
Load all flags - To display
all flags (1-16) on top of the selected display window.
-
Toggle flags on - To
turn on the overlay flags, if they were turned off on the selected display
window.
-
Toggle flags off - To
turn off the overlay flags on the selected display window.
-
Quick flag on/off loop
- To turn on/off the overlay flags continuous for 8 times.
-
Clear all flags - To
clear all the overlay flags on the selected display window.
-
Make blotches on flags
- To mask all flag pixels that are currently displayed as blotches with
color given in the Color to mark flags as blotches field.
To save the blotches as overlay graphics in the displayed window, you have
to quit the L2 Flag Display widget when the blotches are
on, otherwise any other flag display function may clear the blotches.
-
Modify flags' colors
- To open the Flag Color Set Up widget for the user to change
the default colors for flags.
-
Click the Quit button
to quit the L2 Flags Display widget.
How
to mask an image with bathymetry?
-
Load and display the desired
image. The image must have SeaDAS recognized navigation information.
-
Generate the corresponding bathymetry
image:
-
From the Seadisp Main
Menu widget, select the menu item Functions->Generate Bathymetry
Image to display the Bathymetry Image Generation widget.
-
Select the Based on band
number option and the scroll the slider to the band number from the
Band
List Widget for the image to be masked with the bathymetry
mask.
-
Press Okay to start generating
the bathymetry image. When it is created a new entry for this bathymetry
image will be added to the Band List Widget.
-
Use Paint function to generate
masks on the newly created bathymetry image:
-
Select and display the bathymetry
image from the Band List Widget.
-
From the Seadisp Main
Menu widget, select the menu item Functions->Paint
Color (Density Slice) to display the Paint - Density Slice Widget.
-
Select the display window number
for the bathymetry image displayed.
-
Add the range of depth to be
masked to the List of Density Slice Ranges list:
-
Enter the depth range in Min
and Max fields.
-
Click Add button to append
the depth range to the List of Density Slice Ranges.
-
Select the color to mask the
specified depth range from the Color to mark density slices as blotches
selection.
-
Select Mark selected range
as blotches from the drop down Function Menu to perform the
mask.
-
Click the Quit button
to quit the Paint - Density Slice widget.
-
Copy the masked depth graphics
on the bathymetry image to the image to be applied:
-
From the Seadisp Main
Menu widget, select the menu item Functions->Copy Graphics
to display the Copy Graphics widget.
-
Select the From Window number
(the window for the bathymetry) and To Window number (the window of the
image to be applied).
-
Press Go to copy the
bathymetry depth masks from the bathymetry image to the destination image.
How
to change the default display scaling for a given data product?
-
Copy the global seadas defaults
file to your home directory as a 'dot' file:
-
cp $SEADAS/config/seadas_defaults
$HOME/.seadas_defaults
-
Modify your own .seadas_defaults
file:
-
Open the .seadas_defaults file
with your local editor and look for the @SCALING section.
-
Look for the product you with
to change the default scaling on.
-
If your product is listed:
Change
any of the values in the ScaleMin, ScaleMax, Mode or Stype columns.
-
If your product is not listed:
If
a product is not listed, this means that the default will be to scale the
product to it's local min/max range in Geophysical mode using a linear
scaling. Add a new line describing the default scaling desired for
your product.
-
You do not need to restart SeaDAS
for the new scaling defaults to take effect. They will take effect
immediately.
How
to output a transect in ASCII format?
-
Load and display any data product.
-
From the Display Window
widget, select Functions->Output->Data->ASCII.
-
Select Line for the Data
of Interest Within Region.
-
Enter the coordinates of the
two end-points of the line in either pixel/line values or latitude/longitude
values. (If you modify pixel or line, then latitude and longitude
will automatically update and vice versa.)
-
To write out the geophysical
data values along the line joining these two points:
-
Click Write File.
-
To write out other additional
variables in column format such as latitude, longitude, raw data values,
pixel and line values:
-
Click Setup.
-
Click the buttons in front of
the variables you would like to add.
-
You can adjust the order of
the columns by clicking the Move Item Up and Move Item Down buttons.
-
Click Write File.
How
to overlay in-situ data on an image and extract the corresponding
latitude/longitude and data values?
-
Load and display any band from
either the file $SDSDEMO/L1_gac1.hdf or $SDSDEMO/L2_gac1.hdf.
-
From the Display Window
widget,
select Functions->Ship Track.
-
Select and load the ASCII in-situ
file $SDSDEMO/track1.dat. (The Total number of stations listed should
be 16).
-
To plot these points on the
image, select Plot Menu->Overplot Track on Image.
-
To output the latitude, longitude,
image geophysical values as well as in-situ values in a table, select Output
Menu->Track and Image Data.
How
to generate map projections of an image?
-
Load the image and display it
on a window. The image must have SeaDAS recognized navigation information.
-
From the Seadisp Main
Menu widget, select Functions->Projection to bring up the
Seadisp
Projection Function widget.
-
From the Seadisp Projection
Function widget:
-
The image loaded from the Band
List Selection widget to be projected should be listed in the Selection
list section of the
Seadisp Projection Function widget.
If not, click on the Update button to update it.
-
Select the image to be projected
from the Selection list by clicking on the item.
-
Select the projection and change
the defaults for the selected projection if necessary under the Map
Projection Inputs section.
-
Change the output size, if necessary.
-
Press Go to start the
projection process. After projection, the mapped image will be listed
in the Band List Selection widget for display.
-
You can create another projection
by repeating the previous step.
How
to project images into the same map (image composite, mosaic)?
-
Load the images to be composited
into the Band List Selection widget. All images must
have SeaDAS recognized navigation information.
-
From the Seadisp Main
Menu widget, select Functions->Projection to bring up the
Seadisp
Projection Function widget.
-
From the Seadisp Projection
Function widget:
-
The images loaded in the Band
List Selection widget to be projected should be listed in the Selection
list. If not, click on the Update button to update it.
-
Select the images to be projected
from the Selection list by clicking on those items.
-
Select Composite from
the Extra Mapping Options.
-
Select the projection and change
the defaults on Center Lat/Lon,
Lat Limit, and Lon Limit
under the Map Projection Inputs section so that all the images may
be projected inside the map.
-
Change the output size, if necessary.
-
Press Go to start the
projection process. After projection, the composited image will be
listed in the Band List Selection widget for display.
How
to run a non-interactive batch program to output a PNG or PS file containing
a coastline, gridlines and color bar?
-
Look at the file $SDSDEMO/batch_L2png.demo.
-
Either copy it and modify it
to enter in your own file name or product name, or you can use this file
directly. You can enter in the name of any navigable file.
-
To run it, submit the following
command on the unix command line:
-
seadas -b batch_L2png.demo
How
to modify and rebuild a SeaDAS C or FORTRAN program?
-
Find the sub-directory under
$SEADAS/src where the program you want to modify is located.
-
Copy all the files from that
directory to a working directory.
-
Modify the old routines or create
the new routines. The library routines can also be copied here as
new routines for updating or testing.
-
For new routines, Imakefile
has to be modified to include those new routines under the OBJS variable
and 'sdsimake' has to be executed to generate the new Makefile.
-
Type 'make' to
build the program with the updates under the working directory.
-
Test the update program.
-
After test, copy the modified
and the new programs to the original sub-directory under $SEADAS/src.
-
Change the directory to the
original sub-directory and type 'make install' to generate the update program
and move it to the $SEADAS/bin directory.
