LASE_SOLVE Readme 1.0 Introduction This file contains information about the Lidar Atmospheric Sensing Experiment (LASE) SAGE III Ozone Loss and Validation Experiment (SOLVE) sample read software and data files. The LASE_SOLVE data set includes four types of files, nadir and zenith atmospheric scattering ratio profiles, nadir water vapor number density profiles, and nadir water vapor mixing ratio profiles. The LASE_SOLVE data files are stored in ASCII using the Gaines-Hipskind Data Archive Format and can be read with the DAAC-provided read software. Additional information about the LASE data sets can be found in the LASE project and data set Guide documents at the Langley DAAC: http://eosweb.larc.nasa.gov Images of data from the LASE_SOLVE data files can be viewed at the following web site: http://asd-www.larc.nasa.gov/lidar/sol/solve.html Information about the LASE project and instrumentation can be found at http://asd-www.larc.nasa.gov/lase/ASDlase.html Information about the SAGE III Ozone Loss and Validation Experiment is available at http://cloud1.arc.nasa.gov/solve/index.html A document describing the Gaines-Hipskind Data Archive Format is available from the DAAC at http://eosweb.larc.nasa.gov/PRODOCS/lase/table_lase.html This Readme file includes five other sections: Section 2.0 - describes the available read software. Section 3.0 - discusses how to create an executable program from read software source code. Section 4.0 - demonstrates how to invoke the executable program. Section 5.0 - provides general information for the data set. Section 6.0 - provides more detailed implementation notes. If there are questions about using the LASE sample read software, please contact the Langley Science, User and Data Services (SUDS) office. The SUDS 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 SUDS mailing address is: Langley DAAC Science, User and Data Services Office NASA Langley Research Center Mail Stop 157D, 2 S. Wright St. Hampton, VA 23681-2199 USA 2.0 Read Software Files Currently, there is one sample read program which works with all Gaines-Hipskind formatted LASE data sets, read_lase_gh.c. It is written in ANSI C. This program has been tested on the following computers and operating systems: Computer Operating System ------------------- ---------------- Sun Sparc Solaris 2.5 Sun4 SunOS 4.1.3 SGI Origin 2000 IRIX 6.4 HP 9000/735 HP-UX 10.10 DEC Alpha Digital UNIX 4.0A This program is written as an example of how to read in the LASE data. As delivered, it reads in and writes to the screen the file header information followed by each profile's header and data. 3.0 Creating Executable Program Files 3.1 Create with C compiler To compile the program, use the command for the ANSI C compiler. The command varies slightly among operating systems. On Sun Solaris, SGI and DEC Alpha systems the command is: % cc -o read_lase_gh read_lase_gh.c On SunOS systems, use acc in place of cc in the preceding example. On HP-UX systems, the appropriate compiler command is c89 rather than cc. If the appropriate compile command is not found on your system, check to be sure that your PATH environment variable includes the directory that contains the compiler or specify the entire path to the compiler in your command. This compile command creates an executable program file named read_lase_gh. 4.0 Invoking Read Software 4.1 Running the executable version of the LASE Read C Program The executable version of the LASE read C program optionally accepts one command line argument, the name of the LASE data file, e.g. read_lase_gh lase_solve_aer_nadir_19991130 If the file is not in the directory from which the program is invoked, it is necessary to specify the full directory path to the data file along with its name. The program allows for file names up to 50 characters long. If you have renamed the file to a longer name (including the path), you can extend the maximum allowed length by changing the value assigned to the parameter MAX_FILENAME in the #define statement near the beginning of the source code file. Note that the value specified should be the maximum length needed + 1. If the name of the LASE file is not specified at the command line when the program is executed, the user is prompted by the program to enter the file name. A sample of the interactive program execution is provided in Section 6.0. 5.0 Data Set Information 5.1 LASE_SOLVE Data Set LONG NAME FOR THIS DATA SET: Lidar Atmospheric Sensing Experiment data from the SAGE III Ozone Loss and Validation Experiment FILE NAMING CONVENTION: LASE_SOLVE data set files are prefixed with "lase_solve_" to indicate they belong to this data set. This is followed by a a designation of the type of profile stored in the file, 'aer_' for atmospheric scattering ratio data and 'h2o_mr_' for water vapor concentration in mixing ratio and 'h2o_nd_' for water vapor concentration in number density. The next part of the file name indicates whether the data are nadir- or zenith-looking. This is followed by the flight start date in the form yyyymmdd. If more than one flight took place on a given day, there is an additional flight number designator, e.g. _2. Here are two example file names: lase_solve_aer_zenith_19991130 atmospheric scattering ratio profiles in the zenith direction from the flight that began on 11/30/1999 lase_solve_h2o_nd_nadir_20000315_2 water vapor concentration profiles in units of number density in the nadir direction from the second flight on 03/15/2000 VARIABLES: There are ten variables for each profile. The variables names are listed in the file header along with the scale factor and the value used to indicate missing data. The values for these ten variables are written out on one line at the beginning of each profile: Elapsed time in UT seconds Number of values for current recorded time GPS altitude at which data begins (m) Altitude increment (m) GPS altitude of aircraft (m) Hour of day of observation (UT) Minute of hour of observation (UT) Second of minute of observation (UT) Latitude ( +N degrees) Longitude ( +E degrees) followed by the profile values beginning on a separate line. FIRST RECORD OF DATA FROM FIRST DATA FILE: File header and first full profile from the lase_solve_aer_nadir_19991130 file: 36 2310 Browell, Dr. Edward V. NASA Langley Research Center LASE / DC-8 Aerosol Scattering Ratio SOLVE 1 1 1999 11 30 2000 08 01 0.0 GPS altitude of observation (m) Elapsed time in UT seconds from 0 hours on day given by date 1 .001 999999 Aerosol Scattering Ratio 9 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.01 0.01 99999 99999 99999 99999 99999 99999 99999 99999 99999 Number of values for current recorded time GPS altitude at which data begins (m) Altitude increment (m) GPS altitude of aircraft (m) Hour of day of observation (UT) Minute of hour of observation (UT) Second of minute of observation (UT) Latitude ( +N degrees) Longitude ( +E degrees) 0 8 ------------------------------------------------------------------------------- Vertical data interval is 30 m., horizontal data interval is 6 or 9 seconds. Vertical resolution is 60 m, horizontal resolution is 6 or 9 seconds (1.4 or 2.1 km), respectively. These measurements have a maximum estimated error of 5% or 0.1, whichever is larger. The scattering ratio was determined using the JPL Microwave Temperature Profiler (MTP) atmosphere molecular densities preliminary data. No attempt has been made to correct for aerosol or cloud attenuation. ------------------------------------------------------------------------------- 4186 224 1699 30 9139 1 9 46 3801 -11805 999999 16212 1501 1456 1437 1452 1506 1508 1395 1324 1215 1137 1079 1033 1008 980 944 882 741 719 706 672 634 626 602 660 667 679 742 748 729 734 793 728 623 587 551 532 483 437 401 386 362 341 300 265 239 210 189 155 129 114 99 123 127 123 108 121 113 125 141 130 117 128 125 131 136 139 122 121 127 147 131 127 140 129 116 115 93 112 122 116 119 95 90 103 106 99 83 69 71 64 74 71 71 63 65 52 63 66 56 60 62 51 56 46 52 43 49 42 45 65 54 46 48 44 40 35 48 49 35 44 39 37 50 51 59 48 38 48 53 54 59 48 31 40 45 55 56 56 53 54 55 61 66 49 51 54 54 65 64 49 57 57 64 59 62 62 65 67 57 62 59 54 60 61 63 62 60 57 63 69 60 57 56 57 62 65 65 64 61 58 70 66 66 64 70 67 69 70 65 68 69 66 67 67 68 61 62 68 67 66 69 67 68 67 63 63 64 65 59 63 64 58 55 51 53 54 57 55 50 43 38 36 The above-mentioned Gaines-Hipskind format document describes each element of the file header in detail. CONTACTS FOR DATA PRODUCT INFORMATION: Vince Brackett NASA Langley Research Center MS 401A, 21 Langley Boulevard Hampton, VA 23681-1379 USA E-mail: v.g.brackett@larc.nasa.gov Phone: 757-864-5854 Fax: 757-864-7790 Marian B. Clayton NASA Langley Research Center MS 401A, 21 Langley Boulevard Hampton, VA 23681-1379 USA E-mail: m.b.clayton@larc.nasa.gov Phone: 757-864-2841 Fax: 757-864-7790 6.0 Implementation Notes This section gives a brief explanation of how to run the sample read software. 6.1 read_lase_gh C Program The read_lase_gh C program can be used to read any of the LASE_SOLVE data set files. The following is a sample session showing compilation and execution of the read_lase_gh program on the machine named darrin. darrin 3% cc -o read_lase_gh read_lase_gh.c darrin 4% read_lase_gh ********************************************************** LASE_SOLVE READ PROGRAM Version 1.0 20 DEC 2000 This program reads the LASE SOLVE/AFWEX data in the Gaines-Hipskind formatting convention.The input file name is built according to the naming convention formed by the Langley DAAC. Currently the input file name is expected to be no more than 50 characters in length. If you have changed the name of the input file to greater than 50 characters, you will need to modify this program, changing the value of the MAX_FILENAME parameter in the #define statement near the beginning of the file to be at least the maximum length needed + 1. All data files are assumed to be in the current working directory. If the files are located in another directory, please be sure to include the complete path with the file name. The program also accepts input by way of the link command: example ln -s /fs1/LASE/SOLVE/archive_data/lase_solve_aer_nadir_19991130 LASE_LINK This command will make a soft link to the file where it is located. When the program needs a filename as input give it the LASE_LINK name. Platforms tested: SUN (Solaris 2.5 and SunOS 4.1.3) HP (HP-UX 10.10) SGI (IRIX 6.4) Dec Alpha (Digital UNIX V4.0A) Contact: Langley DAAC User and Data Services Office NASA Langley Research Center Mail Stop 157D Hampton, VA 23681-2199 Phone (757)864-8656 Fax (757)864-8807 e-mail: support-asdc@earthdata.nasa.gov http://eosweb.larc.nasa.gov ********************************************************** Press Return or Enter to continue Please enter the LASE data file name lase_solve_aer_nadir_19991130 Investigator: Browell, Dr. Edward V. Originators: NASA Langley Research Center Source of measurments: LASE / DC-8 Aerosol Scattering Ratio Mission: SOLVE Start date: 11/30/1999 Date processed: 6/21/2001 Independent variables descriptions: ------------------------------------------------------------ GPS altitude of observation (m) Elapsed time in UT seconds from 0 hours on day given by date ------------------------------------------------------------ Special comment lines: ------------------------------------------------------------------------------- Vertical data interval is 30 m., horizontal data interval is 6 or 9 seconds. Vertical resolution is 60 m, horizontal resolution is 6 or 9 seconds (1.4 or 2.1 km), respectively. These measurements have a maximum estimated error of 5% or 0.1, whichever is larger. The scattering ratio was determined using the JPL Microwave Temperature Profiler (MTP) atmosphere molecular densities preliminary data. No attempt has been made to correct for aerosol or cloud attenuation. ------------------------------------------------------------------------------- ------------------------------------------------------------ This program as delivered will write all the data values to the screen until the end-of-file is reached. The program will display a screen of values and then prompt you for a response. To skip the prompt enter a for yes when prompted. Then if you wish to interrupt the program use CTRL C. (Press the C key while holding down the Ctrl or Control key). Press Return or Enter to continue. ------------------------------------------------------------- 0.001 <--Scale factor by which one multiplies recorded values of the primary variables to convert them to units specified in VNAME(n). VNAME(n) <-- Aerosol Scattering Ratio 4186 <--The Bounded Independent variable. 223 1729 30 <--The first three auxiliary variables are: Number of values for current recorded time GPS altitude at which data begins (m) Altitude increment (m) The Bounded Independent variable: [Has its constant values defined in the file header.] X(i,1), i=1, NX(1) NX = 223 ----------------------------------------------------- auxiliary variables ------------------- GPS altitude of aircraft (m): 9139.00 Hour of day of observation (UT): 1.00 Minute of hour of observation (UT): 9.00 Second of minute of observation (UT): 46.00 Latitude ( +N degrees): 38.01 Longitude ( +E degrees): -118.05 The Unbounded Independent variable: [The index m is always used to count the independent] [variable marks. The implied loop over m is unbounded.] V(i,m,n), i=1,NX n=1,NV NX = 223 NV = 1 ---------------------------------------------------------------------------- 32.0360 2.9200 2.8320 2.7930 2.8240 2.9310 2.9340 2.7110 2.5700 2.3540 2.2010 2.0870 1.9940 1.9440 1.8890 1.8190 1.6970 1.4160 1.3740 1.3480 1.2810 1.2050 1.1900 1.1420 1.2570 1.2710 1.2930 1.4200 1.4300 1.3940 1.4030 1.5200 1.3900 1.1840 1.1120 1.0400 1.0040 0.9050 0.8160 0.7430 0.7150 0.6660 0.6250 0.5430 0.4750 0.4240 0.3650 0.3230 0.2560 0.2060 0.1750 0.1460 0.1930 0.2010 0.1930 0.1630 0.1900 0.1740 0.1970 0.2290 0.2070 0.1820 0.2020 0.1970 0.2090 0.2190 0.2250 0.1910 0.1890 0.2010 0.2410 0.2100 0.2020 0.2260 0.2060 0.1800 0.1780 0.1330 0.1720 0.1920 0.1800 0.1860 0.1380 0.1280 0.1530 0.1610 0.1450 0.1150 0.0870 0.0900 0.0770 0.0960 0.0910 0.0910 0.0740 0.0780 0.0540 0.0750 0.0810 0.0620 0.0690 0.0720 0.0510 0.0610 0.0420 0.0530 0.0350 0.0470 0.0340 0.0380 0.0790 0.0570 0.0420 0.0450 0.0360 0.0280 0.0190 0.0460 0.0470 0.0190 0.0370 0.0270 0.0230 0.0480 0.0520 0.0670 0.0440 0.0260 0.0450 0.0550 0.0560 0.0660 0.0450 0.0100 0.0300 0.0390 0.0580 0.0610 0.0600 0.0550 0.0560 0.0590 0.0700 0.0800 0.0480 0.0500 0.0570 0.0570 0.0780 0.0760 0.0470 0.0630 0.0620 0.0770 0.0660 0.0730 0.0730 0.0780 0.0820 0.0630 0.0720 0.0670 0.0560 0.0690 0.0710 0.0760 0.0730 0.0690 0.0630 0.0760 0.0860 0.0680 0.0620 0.0610 0.0620 0.0720 0.0790 0.0790 0.0770 0.0720 0.0660 0.0880 0.0810 0.0810 0.0770 0.0890 0.0830 0.0870 0.0880 0.0790 0.0850 0.0860 0.0810 0.0830 0.0830 0.0840 0.0700 0.0720 0.0840 0.0820 0.0810 0.0860 0.0830 0.0840 0.0820 0.0750 0.0750 0.0770 0.0790 0.0670 0.0750 0.0760 0.0640 0.0590 0.0510 0.0550 0.0570 0.0640 0.0590 0.0500 0.0360 0.0250 0.0220 Do you wish to skip this prompt? If so enter for yes. ------------------------------------------------------------ Then if you wish to interrupt the program use CTRL C. [Press the C key while holding down the Ctrl or Control key]. ------------------------------------------------------------ Else press Return or Enter to continue . . . Output of profiles continues until the end-of-file is reached or a CTRL-C is entered (hold down the Control or CTRL key and press the C key). ---------------------------------- Last Modified 12/04/2000