ISCCP DX Native Data Set Readme File 1.0 Introduction This file contains information about the International Satellite Cloud Climatology Project (ISCCP) DX native (NAT) data set. (ISCCP_DX_NAT) The data files are in native format. The home page for ISCCP is located at http://isccp.giss.nasa.gov/ This readme file also includes the following sections: Section 2.0 - provides general information about the data set. Section 3.0 - describes the format of the data. Section 4.0 - provides the user with science parameter information Section 5.0 - describes the sample read software. Section 6.0 - discusses how to invoke the run-time executable. Section 7.0 - provides an example of an actual run of the sample read software. If users have questions while using the ISCCP_DX_NAT sample read software, please contact the Langley Data Center User and Data Services office at: Langley Atmospheric Science Data Center User and Data Services Office NASA Langley Research Center Mail Stop 157D 2 South Wright Street Hampton, VA 23681-2199 U.S.A. Email: support-asdc@earthdata.nasa.gov Phone: (757) 864-8656 FAX: (757) 864-8807 URL: http://eosweb.larc.nasa.gov 2.0 Data Set Description Documentation on the ISCCP_DX_NAT data set can be obtained from the following URL: http://isccp.giss.nasa.gov/doc/documents.html Contact for scientific inquiries: Dr. William B. Rossow NASA Goddard Institute for Space Studies 2880 Broadway New York, NY 10025 email: clwbr@giss.nasa.gov Phone: 212-678-5567 FAX: 212-678-5662 Contact for technical assistance: Violeta Golea NASA Goddard Institute for Space Studies 2880 Broadway, Rm 322A New York, NY 10025 email: vgolea@giss.nasa.gov 3.0 Format and Packaging There are 3 naming conventions for these files. The first 2 conventions are as follows: SATID_YYMMDDHH and SATID.YYMMDDHH SATID - name of the satellite. Note that GMSX0 is used for GMS satellites, GOEX0 is used for the GOES satellite, INS10 is used for INSAT-1, METX0 is used for METEOSAT, where X is the satellite number. For the NOAA satellites, NOAxX is used. The x stands for one of the following: 7 (NOAA-7), 8(NOAA-8), 9 (NOAA-9) or A (NOAA-10), B (NOAA-11), C (NOAA-12), E (NOAA-14), etc. The X can be either A,B,C,D,E,N or S depending upon the geographic region of the DX data. YY stands for two digit year. MMstands for month. DD stands for day. HH equals hour; it can be 00,03,06,09,12,15,18 or 21. Examples: GMS30_86040121 GOE50.84033021 The third filenaming convention is as follows: ISCCP.TTTTTT.V.SATID.YYYY.MM.DD.HH.MM.DCN TTTTTT - data type DX - ISCCP DX data file DXREAD - ISCCP DX Read software DXTOC - table of contents DXREADME - original tape header files for DX products V - version number SATID - satellite identifier GOE-5 (6, 7, 8, 9, 10, 11) MET-2 (3, 4, 5, 6, 7, later MSG) GMS-1 (2, 3, 4, 5, later MTSAT) INS-1 FY2-B NOA-7 (8, 9, 10, 11, 12, 14, 15, 16) GLOBAL - used if multiple or no satellites apply YYYY - year = 1981...2005 (always 4 numbers, fill = 9999) MM - month number = 1...12 (always 2 numbers, fill = 99) DD - day of month = 1...31 (always 2 numbers, fill = 99) HHMM - hour-minute GMT = 0000...2100 (always 4 characters, fill = 9999) DCN - data center name where data originated. For non-data files, the date and time fields may be fill values. Example: ISCCP.DX.3.GOE-7.1995.10.01.0000.AES (data file) ISCCP.DXTOC.3.GOE-7.1995.10.99.9999.AES (table of contents) ISCCP.DXREADME.0.GLOBAL.9999.99.99.9999.GPC (static file) ISCCP.DXREAD.0.GLOBAL.2000.10.03.9999.GPC (read software) Note that not all satellite/day/hour combinations will have a data file. 4.0 Science Parameters Information The ISCCP_DX_NAT data set contains 3-hourly, 30 KM equal-area grid data from various polar and geostationary satellites. More information on the ancillary and data files can be obtained from the International Satellite Cloud Climatology Project (ISCCP) Documentation of New Cloud Datasets documentation available at URL http://isccp.giss.nasa.gov/doc/documents.html 5.0 Description of Sample Read Software The FORTRAN program isccp_dx_read.f has been provided by the data producer as a sample program. It is up to the user to modify the program to output the data of interest. The code was developed using a f77 compiler, it has not been approved for use with f90 or f95 compilers. NOTE: You may have a byte-swapping problem on Linux machines. We have developed a sample read software that will produce the correct results on Linux using the Portland Group Compiler. 6.0 Implementing Sample Read Software The sample read software for most platforms is isccp_dx_read.f It has been tested on Sun, SGI, DEC Alpha and HP UNIX-based workstations. Another sample read software for Linux platforms is linux_isccp_dx_read.f 6.1 How to Compile the Sample Read Software To compile the sample read sofware for most systems, use one of the following: - For SunOS % f77 -o rd_pgm isccp_dx_read.f isccp_dx_read.f: MAIN: dxtabs: dxopen: dxread: BLOCK DATA: - For SGI's % f77 -o rd_pgm -bytereclen isccp_dx_read.f isccp_dx_read.f: MAIN: dxtabs: dxopen: dxread: BLOCK DATA: To compile the sample read software for a linux system using the Portland Group Compiler, use: pgf77 -w -o rd_pgm linux_isccp_dx_read.f Prior to running the program, there must be an input file named fort.10 available. This file is what the program will open and read. There are several ways to create this file: a) copy one of the ISCCP DX Native data files to filename fort.10 b) rename the ISCCP DX Native data file to fort.10 c) use the unix "ln" command to create a symbolic link named fort.10 which points to the data file. We recommend the unix "ln" command for the following reasons: a) a copy of the file will require additional disk resources b) renaming data files can become confusing c) soft links can point to different directories and disk partitions A sample of the "ln" command follows: %ln -s /datadir/ISCCP/dx_910405_gmt0_nat fort.10 %ls -l fort.10 lrwxrwxrwx 1 ownername 10 Apr 22 15:57 fort.10 -> /datadir/ISCCP/dx_910405_gmt0_nat % 7.0 A sample run After the program has been successfully compiled and the file fort.10 has been created, the read program can be executed. A sample of the output follows: % rd_pgm DX HEADER: YEAR 1991 MONTH 4 DAY 5 GMT 0 SATID 43 SATTYP 0 NCHANS 3 NITIMG 1 LON LAT IPOS JPOS 104 1002 250 250 LNDWTR HITOPO SHORE 0 0 0 DAYNIT SNOICE GLINT 1 0 255 MUE MU0 PHI 95 255 255 ITHR VTHR CLOUD 3 0 0 IRAD VRAD ARAD(3) 135 255 52 255 255 ICSRAD ICSTMP ICSPRS 138 141 191 ITMP IPRS 136 191 VCSRAD VCSALB 255 255 VALBTA VTMP VPRS 255 255 255 VTAUIC VTMPIC VPRSIC 255 255 255 NREF NTHR NCSREF 255 0 255 END OF IMAGE ON LINE 400 TOTAL PIXELS READ 113323 The amount and type of output may easily be modified by changing the sample program lines 145 - 164: C*--------------------------------------------------------------------*C C* EXAMPLE: PRINT SOME VALUES FOR A PIXEL *C C*--------------------------------------------------------------------*C IF ( IPOS .EQ.250 .AND. JPOS .EQ. 250) THEN PRINT *,'LON LAT IPOS JPOS',LON,LAT,IPOS,JPOS PRINT *,'LNDWTR HITOPO SHORE ',LNDWTR,HITOPO,SHORE PRINT *,'DAYNIT SNOICE GLINT ',DAYNIT,SNOICE,GLINT PRINT *,'MUE MU0 PHI ',MUE,MU0,PHI PRINT *,'ITHR VTHR CLOUD ',ITHR,VTHR,CLOUD PRINT *,'IRAD VRAD ARAD(3)',IRAD,VRAD,ARAD PRINT *,'ICSRAD ICSTMP ICSPRS ',ICSRAD,ICSTMP,ICSPRS PRINT *,'ITMP IPRS ',ITMP,IPRS PRINT *,'VCSRAD VCSALB ',VCSRAD,VCSALB PRINT *,'VALBTA VTMP VPRS ',VALBTA,VTMP,VPRS PRINT *,'VTAUIC VTMPIC VPRSIC ',VTAUIC,VTMPIC,VPRSIC PRINT *,'NREF NTHR NCSREF ',NREF,NTHR,NCSREF END IF C*--------------------------------------------------------------------*C C* END OF PIXEL LOOP *C C*--------------------------------------------------------------------*C Last updated: July 27, 2001 April 30, 2009