This is the NSIDC DataViewer program, version 1.0, written by David Fanning of the National Snow and Ice Data Center (NSIDC) and released on 11 November 2008. The program is written in the Interactive Data Language (IDL). For additional information about IDL, see the ITTVIS web page (http://www.ittvis.com). DATA FILES Currently the program reads the following NSIDC image data files. nsidc-0001: DMSP-SSM Daily Polar Gridded Brightness Temperatures http://www.nsidc.org/data/nsidc-0001.html nsidc-0032: DMSP SSM/I Pathfinder Daily EASE-Grid Brightness Temperatures http://www.nsidc.org/data/nsidc-0032.html nsidc-0071: Nimbus-7 SMMR Pathfinder Daily EASE-Grid Brightness Temperatures http://www.nsidc.org/data/nsidc-0071.html nsidc-0079: Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMST SSM/I http://www.nsidc.org/data/nsidc-0079.html nsidc-0080: Near Real-Time DMSP SSM/I Daily Polar Gridded Brightness Temperatures http://www.nsidc.org/data/nsidc-0080.html nsidc-0081: Near Real-Time DMSP SSM/I Daily Polar Gridded Brightness Temperatures Processed with the NASA Team (NT) algorithm. http://www.nsidc.org/data/nsidc-0080.html nsidc-0301: AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures http://www.nsidc.org/data/nsidc-0301.html nsidc-0302: AMSR-E/Aqua Daily Global Quarter-Degree Gridded Brightness Temperatures http://www.nsidc.org/data/nsidc-0302.html Sea Ice: AMSR-E/Aqua Daily L3 25Km Brightness Temperature & Sea Ice Concentration Polar Grids http://nsidc.org/data/ae_si25.html Additionally, the program reads BMP, GIF, JPEG, PNG, PPM, SRF, TIFF, DICOM, or JPEG2000 image files . SET-UP The DataViewer set-up depends upon whether you downloaded the DataViewer files as a zip file from an NSIDC web page, or whether you received the DataViewer files on a CD-ROM. The zip file contains IDL source code only, and requires a full IDL license to run the program. The CD distribution contains the IDL source code, but can also be run without an IDL license, using the IDL Virtual Machine. DATAVIEWER AS ZIP FILE If you downloaded the DataViewer zip file, then you have DataViewer source code files only. You must have a full IDL license to run the DataViewer program. When you extract the zip file to your local directory, it will unzip itself into a "dataviewer" directory. You must add this dataviewer directory to your IDL path. See the section below, entitled ADDING DATAVIEWER TO THE IDL PATH, for additional directions. (Note that the sample "data" directory is not included in the DataViewer zip file and must be downloaded separately.) DATAVIWER ON CD-ROM If you received the DataViewer files on a CD, then you can run the DataViewer program directly from the CD using the IDL Virtual Machine. The CD supports LINUX and WINDOWS machines only. In some cases, simply inserting the CD into your CD-ROM drive is all that is required to run the program. However, if the program doesn't run automatically, simply browse to the root directory of the CD. There you will find a shell script, named dataviewer_linux, that you can run to start the DataViewer program if you are running from a LINUX machine. Or, you will find a program named dataviewer_windows.exe that you can double-click to start the DataViewer program on a WINDOWS machine. Program performance will be better if the DataViewer program runs from a local disk, rather than from the CD-ROM. Simply drag the files on the CD to any location on your hard drive, and follow the directions below. The IDL Virtual Machine files are included in the dataviewer/IDL70 directory, so everything needed to run the DataViewer program is on the CD, including sample NSIDC image files. DATAVIEWER DIRECTORIES FILES ON THE CD The following folders or directories are included on the DataViewer CD. root-- this is the main directory of the CD and contains this README file, and the start-up scripts and programs for starting the DataViewer program on various machine architectures. The dataviewer.sav file is also here. This is an IDL save file that contains all the IDL programs files necessary to run the IDL program. config -- this folder contains configuration text files data -- this folder contains sample data files and is only available on the DataViewer CD or by separate download IDL70 -- this folder contains the IDL Virtual Machine files resources -- this folder contains resources for the DataViewer program dataviewer_source -- this folder contains the IDL source code for the DataViewer program, which you will only need if you have a full IDL license and wish to modify the source code itself. config -- this folder contains configuration text files resources -- this folder contains resources for the DataViewer program library -- this folder contains the Catalyst and Coyote Library files used by DataViewer source -- this folder contains the DataViewer IDL source code files. The dataviewer.sav file is the file that can be run on the IDL Virtual Machine. Do not remove this file from its current locaton relative to the other files on the distribution, if you want the DataViewer program to run correctly. (However, you can make shortcuts to this file and install the shortcuts elsewhere, if you like.) FILES IN THE ZIP FILE If you received the DataViewer distribution via a zip file, you must have a full IDL license to run the IDL source code. You must add the dataviewer folder and all of its sub-folders to your IDL path (!PATH). See below for directions. The folders in the zip file are these: dataviewer -- this folder contains the IDL source code for the DataViewer program, which you will only need if you have a full IDL license and wish to modify the source code itself config -- this folder contains configuration text files data -- this folder contains sample image files and must be downloaded separately resources -- this folder contains resources for the program library -- this folder contains the Catalyst and Coyote Library files source -- this folder contains the DataViewer IDL source code files In addition, you might have downloaded a separate zip file of NSIDC sample data files. These files will extract into a data directory that should also be installed in the main dataviewer directory. CONFIGURING THE PROGRAM You can configure the DataViewer program ONLY if you are not running the program directly from the CD. Inside the config folder you will find the file "dataviewer_default.txt". This is the configuration file for the DataViewer application. The only parameter you are likely to want to change initially is the location of the data directory containing your NSIDC image files. Open this configuration file in any text editor, and find this line in the file: DATAVIEWER_DATA_DIRECTORY, 'DEFAULT' Remove the word "DEFAULT" between the single quotes and substitute the location of your data directory. Be absolutely sure the directory name is enclosed in one pair of single quotes. If you fail to make a change, the program will point to the "dataviewer/data" sub-directory. This folder, if it is available, or if you downloaded it, will contain sample NSIDC data files for you to use in the DataViewer. Configuration files are most easily changed from inside the DataViewer program itself. Make modifications to the program from the File menu button. When you are satisfied with the way the program looks and works, choose the "Save Current Configuration..." button. You can save your configuration file as the default, or you can name it something else. You can have as many configuration files as you like. Opening a configuration file from inside the DataViewer program immediately implements that configuration for the program. You can have a different configuration file for each type of image you wish to view, if you like. Note that you CANNOT save a configuration file on the read-only CD-ROM. RUNNING THE PROGRAM How you run the program depends on whether or not you have the file "dataviewer.sav" in your program distribution. If you have this file, and you do not have a full IDL license, then you can run the DataViewer program on the IDL Virtual Machine, which is provided in the CD-ROM distribution. If you have the "dataviewer.sav" file, but you also have a full IDL license, you can choose to run the DataViewer program from source. Simply drag the folder dataviewer_source to any location on your hard drive and add the folder to your IDL path (!PATH). See the directions below for doing so. RUNNING ON THE IDL VIRTUAL MACHINE If you received the DataViewer distibution on CD, you need only to double click the dataviewer_linux shell script, or the dataviewer_windows.ext file in the dataviewer folder to start the program, depending on your operating system. (Some LINUX machines will not allow you to run a shell script by double clicking. On those machines, you will need to run the shell script from a terminal window in the usual way, e.g., by typing ./dataviewer_linux.) On some machines, the DataViewer program will start automatically when you insert the CD-ROM into your machine. The program might run faster if you first copy the contents of the CD to a local hard drive, and run the DataViewer program from there. RUNNING THE DATAVIEWER SOURCE CODE To run the DataViewer source code from a CD distribution, drag the dataviewer_source directory from your DataViewer distribution to a location on your hard drive. Then, you must add the dataviewer_source folder to your IDL path (!PATH). Be sure to add the folder in such a way that all sub-folders are also included in the path. Usually, this means adding a + mark to the directory name or checking the box in front of the directory name, depending upon how you add the directory to your IDL path. ADDING DATAVIEWER TO THE IDL PATH There are many ways to add a folder and its sub-folders to the IDL path (!PATH). See the IDL on-line help for additional information. But one way to make sure all the DataViewer programs are on your IDL path is to enter IDL and type one or the other of the following two commands, depending upon your machine operating system. UNIX OPERATING SYSTEM Here is what you do if you are running IDL on a UNIX operating system. Assume you have installed the dataviewer_source folder in your home directory inside the folder IDL, like this: ~/IDL/dataviewer_source/ From within IDL, you can type this command to add the dataviewer directory and all of its sub-directories to the IDL path: IDL> !PATH = Expand_Path('+~/IDL/dataviewer_source/') + ':' + !PATH WINDOWS OPERATING SYSTEM Here is what you do if you are running IDL on a WINDOWS operating system. Assume you have installed the dataviewer folder on your C drive, inside the folder IDL, like this: C:\IDL\dataviewer_source From within IDL, you can type this command to add the dataviewer directory and all of its sub-directories to the IDL path: IDL> !PATH = Expand_Path('+C:\IDL\dataviewer_source\') + ';' + !PATH Notice the plus sign (+) in front of the directory name for both operating systems. This is an indication to IDL that this directory should be expanded and all the sub-directories in this directory should also be added to the path. Note that in UNIX, the files in the path are separated by colons, whereas in WINDOWS, the files are separated by semi-colons. If you know how to do it, you can also include the appropriate command above in your IDL start-up file, so the DataViewer program is added to your IDL path whenever IDL is started. STARTING THE DATAVIEWER PROGRAM You can run the program from within IDL by typing "dataviewer" at the IDL command line. IDL> dataviewer If you like, you can pass the program the name of an image file to open: IDL> dataviewer, 'C:\data\EASE-F13-NL2006364D.85H.gz' Or, you can pass it the name of a folder. The program will read and open all the image files in the folder. IDL> dataviewer, 'C:\data\' USING DATAVIEWER MENU OPTIONS Selecting Files You can open files in the DataViewer by choosing either the Open Image Files... or the Open Image Directory of Files... buttons under the File menu. The latter button allows you to choose an image directory and the program attempts to open all the image files in the directory. If you use the Open Image Files... button, you have the opportunity to filter files before selection. Multiple files can be selected by holding down the SHIFT or CONTROL keys while you make a selection. Note that if a single file is selected, the window layout is changed to a 1-by-1 layout grid, regardless of the current window layout grid configuration. Changing the Window Layout The DataViewer program appears in a completely resizeable window. Feel free to adjust the size of the window for optimal viewing of images. Simple grab any side or corner of the DataViewer window with your mouse and size accordingly. At any time you can change the layout of the images in the DataViewer window by selecting Change Window Layout Grid button from the File menu. Up to 64 image files in an 8-by-8 grid layout is allowed. Saving the DataViewer Display Window The DataViewer display window can be saved at any time to a variety of file formats. Choose the Save Window As... button from the File menu to save the window in JPEG, PNG, PostScript, and other file formats. Changing Colors Colors for the image, and for different properties in the image (e.g., missing values, out-of-bounds values, etc.) can be changed from the Colors menu. Animating Images All selected images can be animated by selecting the Animate All Images... button from the Operations menu. Stretching or Scaling Images All selected images can be stretched (with Histogram stretching) or rescaled by selecting the Histogram Stretch All Images... button from the Operations menu. Various stretches, included LINEAR, LOG, and GAMMA stretches can be applied. Refreshing Images All images can be refreshed and returned to their default properties by choosing the Refresh All Images button from the Operations menu. Displaying Image Names Typically, images are displayed with their names below the images. This functionality can be turned on or off by selecting the Image Names button from the Operations menu. Displaying Image Color Bars Typically, images are displayed with a color bar above the images. This functionality can be turned on or off by selecting the Colorbars button from the Operations menu. Rearranging Images Images, when they are read into the program, are read in alphabetical order. You can rearrange the images in the current display window by left clicking inside the image and dragging it on top of the image location where you would like the image to be. All other images in the window will move to accommodate this rearrangement. You might have to rearrange the images, for example, prior to animating them. Image Information As you move your mouse over the images in the DataViewer display, you see the name of the image and its value and pixel location displayed in the status bar widget of the program interface. In this way, you can see the value of the image under your cursor. Other Image Properties You can change individual properties of images by right-clicking on individual images. Properties will include changing image colors, scaling the image, displaying the image in its natural size, and annotating the image (see below), among various other properties. Annotating the Image You can annotate any image you like by right-clicking on the image you wish to annotate and choosing the Annotate Image selection from the pop-up menu. If you choose to add text to the annotation, be sure to hit the carriage return when you are finished typing text, for the text to be "set" in the annotation window. You can select and drag annotations in the window to position them where you want them. If you select an annotation and then right click it, you will be able to change that annotation's properties. HELP If you need help with this program or its set-up, please contact NSIDC User Services: National Snow and Ice Data Center (NSIDC) User Services NSIDC/CIRES University of Colorado Boulder, CO 80309 Phone: 303-492-6199 E-Mail: nsidc@nsidc.org