ISCCP_B3_NAT Data Set Readme File 1.0 Introduction This file contains information about the International Satellite Cloud Climatology Project (ISCCP) B3 native (NAT) data set. (ISCCP_B3_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_B3_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_B3_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 New York, NY 10025 email: vgolea@giss.nasa.gov 3.0 Format and Packaging There are three ancillary files that accompany each data file. These ancillary files apply to more than one data file. There is a volume identification file, a table of contents file and a land/water map ancillary file. The land/water map ancillary file is needed to execute the sample read software. There are 2 naming conventions for these files. The first convention is as follows: Satid_YYYYMMDDHH_MMDD.lwm for land/water map Satid_YYYYMMDDHH_MMDD.volid for volume identification file and Satid_YYYYMMDDHH_MMDD.toc for table of contents file, Satid_YYYYMMDDHHx for the image files where Satid can be GMS-X, GOES-X, METEO-X, or NOAA-X (X is the number of the satellite), for INSAT-1B the Satid is INSAT-1; YYYYMMDDHH is the year, month, day and hour of the file. The x in the image file name is usually an a but can be b, c or d if there is more than one observation for that hour. Example: METEO-2_19860701_0716.volid, METEO-2_19860701_0716.lwm, METEO-2_19860701_0716.toc, METEO-2_1986070100a (a data file) The second file naming convention is as follows: ISCCP.TTTTTT.V.SATID.YYYY.MM.DD.HH.MM.DCN TTTTTT - data type B3 - ISCCP B3 data file B3READ - ISCCP B3 Read software B3TOC - table of contents B3LWMAP - fixed Land/Water map for B3 (must have for read software) B3README - original tape header files for B3 products BTREADME - calibration table product BT - radiance calibration coefficient 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.B3.3.GOE-7.1995.10.01.0000.AES (data file) ISCCP.B3TOC.3.GOE-7.1995.10.99.9999.AES (table of contents) ISCCP.B3LWMAP.0.GLOBAL.1983.99.99.9999.GPC (static land/water map) ISCCP.B3README.0.GLOBAL.9999.99.99.9999.GPC (static file) ISCCP.B3READ.0.GLOBAL.2000.10.03.9999.GPC (read software) 4.0 Science Parameters Information The ISCCP_B3_NAT data set contains Reduced Radiance Data from various polar and geostationary satellites. More information on the ancillary and data files can be obtained from the World Climate Research Programme, ISCCP, Description of Reduced Resolution Radiance Data documentation available at URL http://isccp.giss.nasa.gov/doc/documents.html 5.0 Description of Sample Read Software The sample read software for the ISCCP_B3_NAT data set is written in FORTRAN. It was developed by the data provider - NASA Goddard Institute for Space Studies (GISS). 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_b3_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_b3_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 SUN at the command line type: f77 -o b3read isccp_b3_read.f for SGI at the command line type: f77 -o b3read -bytereclen isccp_b3_read.f for DEC Alpha at the command line type: f77 -o b3read -convert big_endian -assume byterecl isccp_b3_read.f To compile the sample read software for a linux system using the Portland Group Compiler, use: pgf77 -byteswapio -w -o b3read linux_isccp_b3_read.f 6.2 How to Run the Sample Read Software The user must also link the land/water map ancillary file and the data file to a specific name so that the executable will know which file to read. This is done with the link command. fort.9 is used for the land/water ancillary file and fort.14 is used for the data file. For example: ln -s METEO-2_19860701_0716.lwm fort.9 ln -s METEO-2_1986070100a fort.14 To execute the program, the user then types the following at the command line: % ln -s METEO-2_19860701_0716.lwm fort.9 % ln -s METEO-2_1986070100a fort.14 % b3read Section: 7.0 A Sample Run % ln -s METEO-2_19860701_0716.lwm fort.9 % ln -s METEO-2_1986070100a fort.14 % b3read > b3read.out ( the > redirects the output, which will print to the screen by default, to the file b3read.out) 1 IMAGE DESCRIPTION ================= IMAGE SEQUENCE NUMBER : 1 SPC ID ESA CODE 4 SATELLITE ID METEO-2 CODE 41 JULIAN DAY (DDD): 182 YEAR (YYYY): 1986 MONTH : 7 DAY : 1 NOMINAL GMT (HHMMSS) : 0 HOUR : 0 MINS : 0 NUMBER OF DATA RECORDS : 82 NUMBER OF SCAN LINES : 416 PERCENTAGE BAD SCAN LINES : 0 GMT (HHMMSS) OF BEGINNING SCAN LINE : 233000 ENDING : 235456 DATE (YYDDD) OF BEGINNING SCAN LINE : 86181 ENDING : 86181 NUMBER OF PIXELS / SCAN LINE : 416 NUMBER OF ACTIVE CHANNELS : 2 CHANNEL 1 IR ( 10.13 - 13.33 ) MICRONS CODE : 2 CHANNEL 2 WV ( 5.48 - 7.55 ) MICRONS CODE : 3 CALIBRATION FLAGS (VIS IR 3 4 5): 0 1 0 0 0 DAY OR NIGHT FLAG 1 ASCENDING EQUATOR CROSSING LONGITUDE 0 GMT 0 DESCENDING EQUATOR CROSSING LONGITUDE 0 GMT 0 1 LOCATION GRID 0 41 161 386 657 966 1266 1519 1614 1655 1518 1265 965 654 368 172 40 0 0 37 163 362 630 928 1213 1441 1549 1587 1419 1217 928 630 368 164 36 0 0 34 142 328 567 833 1089 1286 1392 1405 1296 1086 832 569 329 144 32 0 0 23 118 278 477 705 914 1081 1167 1186 1081 916 702 480 274 117 24 0 0 14 93 211 375 551 719 849 907 925 848 716 553 375 217 90 15 0 * * *some output removed * * 0 37 166 361 630 929 1213 1443 1549 1586 1422 1218 927 633 368 160 39 0 0 44 167 398 672 987 1288 1543 1640 1681 1542 1287 987 669 379 181 41 0 CHAN 2 ISCALE 0 100 0 0 0 CHAN 3 ISCALE 0 100 100 0 0 CALIBRATION INFORMATION CHANNEL 2 TABLE 6 UNITS : KELVIN SOURCE : GLOBAL PROCESSING CENTER COEFS : 1.0000 0.0000 -1.0000 0.0000 0.0000 CHANNEL 3 TABLE 6 UNITS : KELVIN SOURCE : GLOBAL PROCESSING CENTER COEFS : 1.0000 0.0000 -1.0000 0.0000 0.0000 1 CALIBRATION TABLE ================= COUNT CHANNEL ___________ 1 2 3 4 5 ------- ------- ------- ------- ------- 0 0.00 346.32 270.75 1 0.00 345.96 270.67 2 0.00 345.55 270.50 * * * some output removed * * 250 0.00 0.00 0.00 251 0.00 0.00 0.00 252 0.00 0.00 0.00 253 0.00 0.00 0.00 254 0.00 0.00 0.00 255 0.00 0.00 0.00 ---< LNDWTR MAPS INITIALIZED >--- Last updated: July 27, 2001 April 30, 2009