This package consists of a group of files written in C which are used to read HDF files. The examples provided in the main (BDS_readhdf.c) program are written specifically for SDS(s) and Vdata(s) in BDS files. Information on the structure of the BDS file can be found in "Clouds and the Earth's Radiant Energy System (CERES) Data Management System - Data Products Catalog". An on-line version can be downloaded from: http://asd-www.larc.nasa.gov/ceres/docs.html HDF information, documentation, tutorials, libraries, etc. can be found on-line at the URL: http://hdf.ncsa.uiuc.edu A utility (hdp) is provided in the HDF libraries which will extract information about the contents of the HDF file. The commands: hdp -H hdp dumpsds [-options] hdp dumpvd [-options] vshow [+|+vdata_id] These will give information as to the size, type, and names of the HDF data structures. The [-H] option will give help information. This package consists of the following files. 1) BDS_readhdf.c 2) BDS_readHDFfuncs.c 3) BDS_HDFread.h 4) compile_BDS_readhdf 5) CER_BDS_TRMM-PFM_ReadDemo_000019.19980105 6) BDS_ReadDemo.output 7) readme_cer_bds_trmm-pfm_edition1 To read the files, first unzip them with Info-Zip software. Information about downloading and using this freeware is available at the following URL: http://www.info-zip.org/pub/infozip/ 'BDS_readhdf.c' is the main program which accesses the HDF reading functions. It consists of four examples of accessing SDS and Vdata from a BDS file. 'BDS_readHDFfuncs.c' is a file consisting of C functions that is linked with 'BDS_readhdf.c' and calls HDF functions. 'BDS_HDFread.h' is a header file for 'BDS_readhdf.c' and the BDS HDF read functions. 'compile_BDS_readhdf' is a sample script to compile the BDS_readhdf program in a UNIX environment. The script must be modified for different platforms to properly compile the programs and correctly link the HDF libraries. 'CER_BDS_TRMM-PFM_ReadDemo_000019.19980105' is a sample BDS file which used by the examples in 'BDS_readhdf.c' 'BDS_ReadDemo.output' is the output produced by the BDS read program for the supplied sample BDS data file. 'readme_cer_bds_trmm-pfm_edition1' is this information file. Four examples are provided in 'BDS_readhdf.c' illustrating how to access data from the BDS file. Read the comments describing the examples in 'BDS_readhdf.c'. To execute 'BDS_readhdf.c': 1) Download and install the HDF libraries from the NCSA web site ( http://hdf.ncsa.uiuc.edu ). This code uses version HDF4.1r1. Other versions of the HDF libraries may not work with this code. NCSA uses the gnu gzip compression utility for some packages. If you do not already have this software which is needed to uncompress the file, you can obtain it from one of the Gnu mirror sites listed at http://www.gnu.org/order/ftp.html 2) Edit the sample script 'compile__readhdf' to link the HDF libraries and compile the C programs. Check the permissions on this file to make sure execute permission is set for the owner: ls -l compile_BDS_readhdf should display something like -rwxr--r-- 1 OWNER GROUP 1450 Mar 6 14:49 compile_BDS_readhdf where OWNER and GROUP are the file owner and group information. The owner executable permission is the x in -rwxr--r--. To set proper permissions (assuming you are the file owner), type chmod 744 compile_BDS_readhdf 3) Execute the script 'compile_BDS_readhdf' to create the executable BDS read program 'bds_rd' by typing source compile_BDS_readhdf or, on some systems you need only type compile_BDS_readhdf 4) Execute 'bds_rd HDFfilename'. For the example program given type: bds_rd CER_BDS_TRMM-PFM_ReadDemo_000019.19980105 If there are questions about using the CERES_BDS_TRMM-PFM_Edition1 read software, please contact the Langley Science, Users, and Data Services (SUDS) Office at: NASA Langley Atmospheric Sciences Data Center Science, Users, and Data Services NASA Langley Research Center 2 South Wright Street Mail Stop 157D Building 1268C Hampton, VA 23681-2199 USA E-Mail: larc@eos.nasa.gov Telephone: (757) 864-8656 FAX: (757) 864-8807