An Introduction to the GHRC Orbit Plotter ********************************************** Program ******** Table of Contents ================== o 1.0 Introduction o 2.0 Required Files o 3.0 Satellite Element Set Data o 4.0 Installation Instructions o 5.0 Accessing Software from NCSA o 5.1 HDF Library o 5.2 Mosaic o 6.0 Contact Information 1.0 Introduction ================= The orbit plotter program plots the orbits of up to four satellites simultaneously on one of several map projections. The user may specify a time range and a geographic area of interest. The orbit plotter uses this information to determine if the specified satellites observe a given area during a given time period. The coincidence search program allows a user to search for times when two, three or four satellites simultaneously observe the same geographic area. The search criteria my be constrained by time, geographic area and/or distance between satellites. Both program use an archived database of element set data to calculate th orbits using a model supplied by the Colorado Center for Astrodynamic Research (CCAR). Orbits may be extrapolated for future times but the accuracy of the orbit decreases as the temporal distance from the last element set increases. 2.0 Required Files =================== The following files must be obtained in order to execute the orbit plotter/coincidence search program. FILE FILE DESCRIPTION 1. orbit.tar.Z source code for orbit plotter/coincidence search program 2. orbit.README installation instructions for orbit.tar.Z file 3. common.tar.Z common subroutine library 4. common.README installation instructions for common.tar.Z 5. ODL.tar.Z Object Definition Library - for SGI Irix 5.2 ONLY (see note below) 5a. ODL2.tar.Z Source code for the Object Definition Library. You need to compile this! 6. ODL.README installation instructions for ODL.tar.Z 7. HDF.tar.Z Hierarchical Data Format Library for SGI Irix 5.2 ONLY (see note below) 8. HDF.README installation instructions for HDF.tar.Z NOTE: The orbit and common 'packages' make use of the ODF and HDF libraries. The files in ODL.tar.Z and HDF.tar.Z contain only BINARY libraries which have been compiled under Irix 5.x for use ONLY on a Silicon Graphics system. If you will be using another platform to run the orbit plotter/coincidence search program, you must retrieve the latest version of from NCSA. Instructions for accessing the libraries at NCSA are provided in Section 5.0. ODL2.tar.Z is the source code which can be compiled on other than SGI platforms. On-line help is available during the execution of the orbit plotter/coincidence program. In order to access this help function, a copy of xmosaic is needed on the host machine. A copy of xmosaic can be obtained from NCSA and instructions for access are provided in Section 5.0. 3.0 Satellite Element Set Data =============================== The orbit plotter/coincidence search program requires input from an external database of satellite element data. These data are available from a variety of sources. One source of the data is the ftp.afit.af.mil archive site. Included in the anonymous ftp account at the GHRC are a checkpointed database (1994-09-15) and programs that can be used to retrieve data on a regular basis. These files are: 1. elements.tar.Z program source code and checkpointed database 2. elements.README installation instructions for elements.tar.Z These particular files are not required to execute the orbit plotter/coincidence search program. However, an element set database for the satellites of interest MUST be provided. The database provided must follow the formatting requirements that are described in the elements.README file and the dataset index file. 4.0 Installation Instructions ============================= The files required to execute the orbit plotter/coincidence search program are available via anonymous ftp from MSFC by implementing the following steps. ftp microwave.msfc.nasa.gov for username, enter: anonymous for password, enter: your email address change directory: cd pub/software/tools set transfer to binary: binary download the files specified in Section 2.0 using standard ftp protocol After all files have been downloaded, read all README files for specific installation instructions. The software should be installed in the following order: 1. HDF library 2. ODL library 3. xmosaic (if on-line help function is desired) 4. common 5. elements or an equivalent element set database 6. orbit 5.0 Accessing Software from NCSA ================================= 5.1 HDF Library =============== HOW TO GET HDF LIBRARY AND TOOLS This section gives the instructions for retrieving the HDF files. 1. First connect to the NCSA ftp server. ftp ftp.ncsa.uiuc.edu 2. Login as anonymous giving your Internet e-mail address as the password. Get the README.FIRST and README files. These files contain most of the information referred to below. 3. Change to the HDF directory. ftp> cd HDF There you will find several files beginning with HDF such as: 8 10760 wsstaff 512 Mar 9 07:01 HDF3.2r3 8 10760 wsstaff 512 Mar 9 07:02 HDF3.2r4 2 2519 wsstaff 512 Mar 9 07:02 HDF3.3 REMINDER: Go to the top level directory and change to the UNIX/XCollage directory to get the Collage1.0 tool before logging off ftp. 4. Change to the directory with the latest version. Any ALPHA release may not be the best choice. ftp> cd HDF3.2r4 5. Change directories to the tar directory. ftp> cd tar Here are approximately nine files beginning with "hdf.tar.Z.part". 6. Insure binary mode transfer and obtain all of these files. ftp> binary ftp> mget hdf.tar.Z* 7. Return to your home system. ftp> bye 8. The files obtained contain the entire HDF library, examples, and utilities. They must be concatenated into one big file. cat hdf.tar.Z* > hdf.tar.Z 9. Uncompress the file, yielding a tar file named "hdf.tar". uncompress hdf.tar.Z 10. Extract the contents of the tar file with the tar utilty. tar -xvf hdf.tar This will create several directories including an hdf directory. 11. After the tar command is completed, there will be a series of Make files in the directory. There should be one that corresponds to your machine type. Editing of the makefile is necessary to note where some files are but ample comments are included. Read the INSTALL.ALL file for further help. After editing, run the makefile. This will install everything, creating the lib/libdf.a directory and file. (Note: All utilities may not make. The libdf.a file is the most important.) Once the lib/libdf.a file is created, you have the hdf library. This can then be used to compile the extract.c, getorb.c, and getfiledesc.c utilities included with this release. 5.2 Mosaic ========== How To Download And Run NCSA Mosaic ----------------------------------- NCSA Mosaic is an Internet-based global hypermedia browser, available free for academic, research, and internal commercial use. If at any time you have questions or problems with NCSA Mosaic, please feel free to send electronic mail to: mosaic-x@ncsa.uiuc.edu The NCSA Mosaic anonymous FTP distribution site is ftp.ncsa.uiuc.edu. Program files are in directory /Mosaic. Executable Binaries ................... The easiest way to download Mosaic is to retrieve an executable binary from subdirectory Mosaic-binaries. The following binaries are distributed: Mosaic-sun.gz Sun 4, SunOS 4.1.x Mosaic-sun-lresolv.gz Sun 4, SunOS 4.1.x, no DNS Mosaic-sgi.gz Silicon Graphics, IRIX 4.x. Mosaic-indy.gz Silicon Graphics, IRIX 5.x. Mosaic-ibm.gz IBM RS/6000, AIX 3.2. Mosaic-dec.gz DEC MIPS Ultrix. Mosaic-alpha.gz DEC Alpha AXP, OSF/1. Mosaic-hp700.gz HP 9000/700, HP/UX 9.x To download a binary, put your FTP session into binary mode (type 'binary', without the quotes), pull down the file, quit the FTP session, uncompress the binary (type, e.g., 'gunzip Mosaic-sun.gz' without the quotes), make the binary executable (type, e.g., 'chmod 755 Mosaic-sun'), and execute the binary. Run-Time Problems ................. There are three problems that you may encounter when you run a Mosaic binary for the first time. They are discussed in order of decreasing severity. (a) Mosaic dumps core. Most likely, this is because your system is slightly misconfigured. Try starting Mosaic back up with with the following command-line flag: Mosaic-sun -ghbnie If Mosaic works with the -ghbnie flag, then your system is core dumping while trying to discover its own fully qualified hostname with the gethostbyname() system call; contact your system or network administrator. If Mosaic still doesn't work, follow the instructions displayed as Mosaic dumps core and send a bug report to mosaic-x@ncsa.uiuc.edu. (b) An error message shows up in the Mosaic window saying that Mosaic couldn't retrieve a file over the network. There are three possible explanations: (1) You aren't connected to the Internet. (2) You are behind a firewall. (3) Your system can't resolve the remote machine name 'www.ncsa.uiuc.edu'. (There is the additional possibility that the central NCSA document server might be temporarily down, in which case you should try running Mosaic again in a few minutes.) If the problem is (1) or (2), your network administrator will have to find some way to fix it. If the problem is (3), and you're running on a Sun, try the binary named Mosaic-sun-lresolv. If this still doesn't work, or if you're not on a Sun, then contact your network administrator. (c) You see lots of warning messages in the terminal window. If you get warning messages (generally about missing "keysyms" or fonts) but the Mosaic window comes up and stays up, then the situation isn't serious and Mosaic will run normally. Read the online Frequently Asked Questions for more information on how to make the warning messages stop showing up. Some X servers refuse to run Mosaic when all of the fonts Mosaic requests upon startup are missing. If this happens to you, send mail to mosaic-x@ncsa.uiuc.edu for more help. Source Code ........... The complete Mosaic source code distribution is located in subdirectory Mosaic-source. The distribution comes as a single compressed tar file, and can be compiled on most Unix systems. You must have the X11R4 (or later) and Motif 1.1 (or later) header files and libraries on your system to compile Mosaic. See the README in the source code distribution for more information on compiling Mosaic. External Viewers ................ Mosaic assumes the presence of a number of external viewers -- programs that Mosaic can use to allow you to view images, movies, PostScript files, etc. that are retrieved over the network. See the subdirectory Mosaic-viewers for copies of the normal source distributions of some of these viewers. We strongly recommend downloading and installing these viewers if they do not already exist on your system, as Mosaic will be much more useful with them present. For more information on these viewers, see the online documentation. More Information ................ More information is available online, through Mosaic. 6.0 Contact Information ======================= The orbit plotter/coincidence search program can be obtained from the the GHRC User Services Office: GHRC User Services Global Hydrology Resource Center 320 Sparkman Dr. Huntsville, Alabama 35805 phone: 256-961-7932 email: ghrcdaac@itsc.uah.edu