MOPITT Level 2 Viewer Software Readme File ------------------------------------------ 1.0 Overview This file contains information about installing and running the MOPITT L2 Viewer software package for plotting images from MOPITT Level 2 data files. The tool is written in Exelis Visual Information Solutions IDL programming language. It can be run either with a licensed version of the IDL package or by using the IDL Virtual Machine application that can be obtained from ITT Visual Information Solutions free of charge as described below. It has been tested with IDL versions 6.1, 6.2, and 6.3, and requires the use of IDL 6.1 or higher. The source code program files can be opened with any text editor to examine the code. The MOPITT L2 Viewer software is distributed as a tar file. Use the instructions for your operating system below to install the Viewer software. 2.0 Installing and Running the Program 2.1 Extracting the files from the delivery package The software is packaged as a tar file, MOPITT_L2Viewer.tar, which can be opened on both Unix and Windows systems. The tar file contains a number of IDL source code (.pro) files, two IDL structure definition (.cfg) files, and a MOPITT logo (.jpg) image file. On Unix systems, use the following command to extract the files onto on your system: tar xvf MOPITT_L2Viewer.tar A MOPITT_L2Viewer directory will be created and the files will be extracted into that directory. On Windows systems, a package such as WinZip for extracting from zipped files will also extract from tar files. Use the package's extract capability to put on your system. Again, a MOPITT_L2Viewer directory will be created in the extract destination you specify. 2.2 Creating a configuration file To simplify running the program, you may optionally create a file named config.txt in the MOPITT_L2Viewer directory created when you installed the program files. This file may be created using any text editor. The file should contain two lines. The first line specifies the full directory path where your MOPITT data files are located. The second line specifies the full directory path where you want to save any plot image files you create with the program. As an example, on Unix your config.txt file might look like: /home/mydir/mymopittdata /home/mydir/mymopittimages or on a PC it might look like c:\mydir\mymopittdata c:\mydir\mymopittimages 2.3 Using a licensed version of the IDL software package The package must be compiled in IDL before it can be run. To do this on Unix or PC systems, use the IDL development environment, idlde. On Unix systems, type "idlde" at the Unix prompt. On a PC or Macintosh, click on the IDL PC desktop icon, or PC users select IDL from the Start menu. Once in idlde, under File on the menu bar, choose "Open Project" and then select the file MOPITT_L2Viewer.prj. Then under Project on the menu bar, choose Compile and then All Files. Then again under Project, choose Run. 2.4 Using the IDL Virtual Machine The IDL Virtual Machine is a free runtime version of IDL available from Exelis Visual Information Solutions at http://www.exelisvis.com/ The IDL VM software may be downloaded from this site or ordered from ITT VIS on CD at no cost. The site provides installation instructions. To run an IDL VM application, 1) In Unix At the Unix command prompt, type idl -vm. Click anywhere on the IDL VM splash screen to continue. A dialog box appears for selecting the IDL save file. Navigate to the MOPITT_L2Viewer directory where created when you installed the package files, and select the MOPITT_L2Viewer.sav file. Click the Open button and the program will start. 2) In Windows, From Windows Explorer, drag the MOPITT_L2Viewer.sav file onto the IDL Virtual Machine Desktop icon created when the IDL VM was installed. Click on the splash screen, and the coregister_L1B2_L2AS program will start. or Click on the IDL Virtual Machine desktop icon or run the IDL Virtual Machine from the Start menu and click on the splash screen to continue. Use the dialog box that appears to navigate to the directory where you placed the MOPITT_L2Viewer.sav file, select that file, and click Open to start the coregister_L1B2_L2AS program. 2.5 Program Execution The basic procedure is to select the Load Data File Option from the File menu item in the initial MOPITT L2 Viewer, and then create a list of up to three data files to work with using the Add button in the Choose data files window. Once the file list is created, click on the Ok button to bring up the Data Selector window where plots are specified. The Plot menu button in that window will display the selected data using the specified plot parameters. From the resulting Plot window, plots may be saved as files in various graphic formats. 3.0 Additional Information and Assistance Information about MOPITT data, including data field descriptions and file naming conventions, is available from the NASA Langley Atmospheric Science Data Center MOPITT web page, http://asdc.larc.nasa.gov/project/MOPITT Assistance with Viewer software and data questions is available from the NASA Langley Atmospheric Science Data Center User and Data Services office. The office may be reached by E-Mail: support-asdc@earthdata.nasa.gov, by telephone at (757)864-8656, or by FAX at (757)864-8807. The mailing address is: Atmospheric Science Data Center User and Data Services NASA Langley Research Center Mail Stop 157D Hampton, VA 23681-2199 USA