Langley DAAC Version Number:   LD_008_021_004_00_00_0_19990407
                                               
                                               

                        SAGE I and II Profiles Readme


1.0 Introduction

This document contains information on running and compiling the read software
for the Stratospheric Aerosol and Gas Experiment (SAGE) I and II profiles. 
There is read software available for:
                  SAGE I Aerosol Profiles data set 
                  SAGE II Aerosol Profiles data sets
                  SAGE II Ozone Profiles data sets
                  SAGE II Nitrogen Dioxide (NO2) Profiles data sets
                  SAGE II Water Vapor Profiles data set 
The SAGE I data set is only available in the Hierarchical Data Format
(HDF). All of the SAGE II data sets are available in HDF, ASCII and binary
formats with the exception of the SAGE II Water Vapor Profiles. This data
set is only available in HDF. This readme file includes the following sections:

Section 2.0 - describes sample programs (source files).
Section 3.0 - discusses how to create the executable from the programs.
Section 4.0 - demonstrates how to invoke the run-time executables.
Section 5.0 - provides general information on all of the data sets.
Section 6.0 - provides more detailed implementation notes.

If users have questions while using the SAGE I and II sample read software, 
please contact the Langley DAAC User and Data Services office at:  

EOSDIS Langley DAAC 
Science, Users and Data Services Office
NASA Langley Research Center
Mail Code 157D
2 South Wright Street
Hampton, Virginia 23681-2199
U.S.A.

E-mail:   larc@eos.nasa.gov
Phone:    (757)864-8656
FAX:      (757)864-8807


2.0 Read Software File 

The sample read program for the SAGE data sets are developed in the C language
(to read HDF data files and the ASCII data files) and IDL (to read the binary
data files). The C program has been tested on Sun (Solaris 2.5), Dec Alpha V4.0A,
SGI Irix 6.2, and HP UNIX-based workstations. All library functions in the C 
source code are tested for ANSI C conformance. To generate the read software 
for the SAGE data, the HDF library and include files must be linked at 
compilation time. A compilation script is included for the convenience of 
creating the executable files from the source files. These files and their 
purposes are listed as follows:

       compile_sage_read - contains a set of commands to build the 
       run-time executable for reading the HDF data.
       
       read_sage.c - reads the HDF SAGE I Aerosol Profiles, SAGE II Aerosol 
       Profiles, SAGE II Ozone Profiles, SAGE II Nitrogen Dioxide Profiles, 
       and SAGE II Water Vapor Profiles data.
       
The ASCII read software for the ASCII version of the SAGE II data sets are 
generated by the following files:

       read_sag2_aer.c - reads the ASCII SAGE II Aerosol Profiles.

       read_sag2_no2.c - reads the ASCII SAGE II Nitrogen Dioxide (NO2)
       Profiles.

       read_sag2_ozn.c - reads the ASCII SAGE II Ozone Profiles.
       
The binary read software for the binary version of the SAGE II data sets 
are generated by the following files:

       read_sage2_aer.pro - reads the binary SAGE II Aerosol Profiles

       read_sage2_no2.pro - reads the binary SAGE II Nitrogen Dioxide Profiles

       read_sage2_ozn.pro - reads the binary SAGE II Ozone Profiles
       
These sample programs were written in IDL.

NOTE:  These data files were created on a Dec Alpha system. Therefore, if you
are planning to read the data with these programs on a Dec Alpha, you must
modify your code. Each code states which lines must be modified if you are
on a Dec Alpha. Otherwise, ignore this statement.

January 26, 1999
NOTE:  Versions of IDL older than 5.2 are not able to read unsigned 16-bit
integers correctly. Therefore, when selecting the Bit Flag parameters,
most data values are printed correctly with the exception fo a data value
something like this... FFFF8000. The value should be 8000. At this time,
we were able to correct the problem by an "and" statement which strips
off the FFFF.  This bit flag only appears in the SAGE II Ozone Profiles
and the SAGE II NO2 Profiles in native format ONLY!


3.0 Creating Executable Files 

The following sections describe how to create the executables for the HDF, 
ASCII, and binary formats.

3.1 Creating the Executables for the HDF data format files

The user has two methods of building the sample read programs from the source
files. The user is able to build the code from the command line or for
conveince, build the code using the C shell script that was provided with
the sample read software.  All files are defined in Section 2.0.  Users
working with the HDF data format files need the HDF libraries in order to
build the executable for the sample read software.

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] <HDF file name>
hdp dumpvd [-options] <HDF file name>
vshow <HDF file name> [+|+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.

Download the HDF libraries from the NCSA web site
( http://hdf.ncsa.uiuc.edu ).  This code uses Version HDF4.1r2.
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

Once all of the HDF libraries are located on your system, you are now 
ready to compile the sample read software.

Currently, the Langley DAAC is working with Versions 4.1r1 and 4.1r2 of the
HDF library.

3.1.1 Create an executable using the C shell scripts

The files that contain the C shell scripts are those files that begin with
the word "compile" in the file name. To build the executable that reads
the HDF data format files for the SAGE I Aerosol data set, the SAGE II
Aerosol, Ozone, Nitrogen Dioxide, and Water Vapor data sets, you must obtain
the file script "compile_read_sage."

Refer to (edit) the sample script 'compile_read_sage' to link the HDF 
libraries and compile the C program. Check the permissions on this file to 
make sure execute permission is set for the owner:
   	ls -l compile_read_sage
should display something like
   -rwxr--r--   1 OWNER     GROUP        4157 Jan 14 00:42 compile_read_sage
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_read_sage

Execute the script 'compile_read_sage' to create the executable by typing
   	source compile_read_sage
or, on some systems you need only type
   	compile_read_sage

To run the executable at the command line, just type:
     read_sage


3.1.3 Create with the compiler

This method uses the combinations of the HDF libraries, the HDF includes 
files, and the programs provided for the data sets (read_sage.c). To build 
the executable for these data sets, at the command line prompt type:

On your Sun system, the following command was used to build the sample
software:

gcc -o read_sage read_sage.c -I/usr/local/hdf/include \
    -L/usr/local/hdf/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib

NOTE:  You will have to modify the paths for the HDF libraries to the
correct location on your system.


On your SGI Irix 6.2 system, the following command was used to build the sample
software:

cc -ansi -n32 -mips3 -O -s -o read_sage read_sage.c  \
       -I/usr/people2/paula/HDF/4.1r2_irix6.2/include \
       -L/usr/people2/paula/HDF/4.1r2_irix6.2/lib -lmfhdf -ldf -ljpeg -lz

NOTE:  You will have to modify the paths for the HDF libraries to the
correct location on your system. Also, when you compile the code, you will get
some warning messages stating that all of the libraries expressed in the 
compilation call when not used. Just disregard those warning messages. You
will still get the executable.


On your Dec Alpha V4.0A system, the following command was used to build the 
sample software:

cc -o read_sage read_sage.c -I/usr/local/HDF4.1r1/include -L/usr/local/HDF4.1r1/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib 

NOTE:  You will have to modify the paths for the HDF libraries to the
correct location on your system.


On your HP system, the following command was used to build the sample
software:

gcc -o read_sage read_sage.c -I/usr/local/HDF4.1r1/include -L/usr/local/HDF4.1r1/lib -lmfhdf -ldf -ljpeg -lz -L/usr/lib 

NOTE:  You will have to modify the paths for the HDF libraries to the
correct location on your system.

Remember that your paths on your system may be different than these listed
above. Please modify your paths accordingly.
     
3.2 Creating the Executables for the ASCII data format files

The C program has been tested on Sun (Solaris 2.3), HP UNIX-based , and 
SGI workstations. All library functions in the C source code are tested for 
ANSI C conformance. To execute the program, follow the instructions for the 
various platforms:

 Sun (Solaris 2.3):  at the command line prompt, type:

     cc -o read_sag2_ozn read_sag2_ozn.c 

 HP-UX:  at the command line prompt, type:

     cc -Aa -o read_sag2_ozn read_sag2_ozn.c

 SGI:  at the command line prompt, type:

     cc -o read_sag2_ozn read_sag2_ozn.c 

3.3 Creating the Executables for the binary data format files

The read software for the binary data has been written in IDL (Interactive Data
Language).  To compile the program, at the IDL prompt, type (for example):

         .compile read_sag2_aer.pro

To run the program, type the following command at the IDL prompt:
  
         read_sag2_aer


4.0 Invoking Read Software

This section illustrates the invocation of the executable file. Section 
6.0 describes how to run the read program for the SAGE data sets.
 
4.1 Invoking the HDF Read Software

Data Set               Read Software         Executable Name
--------               -------------         ---------------
SAGE1_AERO_PRF         read_sage.c           read_sage
SAGE2_AERO_PRF         read_sage.c           read_sage
SAGE2_NO2_PRF          read_sage.c           read_sage
SAGE2_O3_PRF           read_sage.c           read_sage
SAGE2_H2O_PRF          read_sage.c           read_sage

The HDF read program is able to read SAGE I Aerosol Profiles 
data, SAGE II Aerosol Profiles data, SAGE II Ozone Profiles data, SAGE II 
Nitrogen Dioxide Profiles data, and SAGE II Water Vapor Profiles data. The 
executable prompts the user for the particular data set to read 
and the filename of the data set (including the pathname). To execute 
the program, at the command line prompt type:

        read_sage

read_sage will read the HDF data and send the output to a file with 
the same name as the input file but will include a ".rpt" extension. This 
report file will be written in the working directory. The program will then 
prompt the user to select which parameters to output to the report file. This
assumes that the data input files are located in the current working directory
as well. For example, if the input file is 'sag2_no2_prf_8410,' the output
will be written to the file 'sag2_no2_prf_8410.rpt.'

A customized menu has been provided to enable the user to select parameters.

See Section 6.0 IMPLEMENTATION NOTES for an actual run of the code.

4.2 Invoking the ASCII Read Software 

The ASCII read software is a bit different. There is one read software program
for each SAGE II ASCII data set.

Data Set               Read Software         Executable Name
--------               -------------         ---------------
SAGE2_AERO_PRF_ASC     read_sag2_aer.c       read_sag2_aer
SAGE2_NO2_PRF_ASC      read_sag2_no2.c       read_sag2_no2
SAGE2_O3_PRF_ASC       read_sag2_ozn.c       read_sag2_ozn

After the compilation, the program can be invoked with the executable name
'read_sag2_ozn'. An output file will be created in the working directory
with the same name as the data file but having the extension '.rpt.'
For example, if the input file is 'ozn8410_ascii', the output will
be written to the file 'ozn8410_ascii.rpt.'

A customized menu has been provided to enable the user to select parameters.

4.3 Invoking the binary Read Software 

There is one Interactive Data Language (IDL) read software program for each 
SAGE II binary data set.

Data Set               Read Software           IDL Executable
--------               -------------           --------------
SAGE2_AERO_PRF_NAT     read_sag2_aer.pro       read_sag2_aer
SAGE2_NO2_PRF_NAT      read_sag2_no2.pro       read_sag2_no2
SAGE2_O3_PRF_NAT       read_sag2_ozn.pro       read_sag2_ozn

To compile the program, at the IDL prompt, type (for example):

          .compile read_sag2_aer.pro

To run the program, at the IDL prompt, type:
  
          read_sag2_aer

An output file will be created in the working directory with the same name as the 
data file but having the extension '.rpt.' For example, if the input file is 
'ozn8410_32-bit,' the output will be written to the file 'ozn8410_32-bit.rpt.'
    
A customized menu has been provided to enable the user to select parameters.


5.0 Data Sets Information

Currently, the read program, read_sage.c, is able to read five data sets, 
SAGE I Aerosol Profiles, SAGE II Aerosol Profiles, SAGE II Ozone Profiles, 
SAGE II Nitrogen Dioxide Profiles, and SAGE II Water Vapor Profiles. The
following subsections describe these five data sets. The information on these
data sets were obtained from text files or documents from the data producer. 
The high-level data set descriptions, the data files, the variables in the data
files, and the contacts for data production are given under each data set. 

NOTE:  There are two parameters in these data files called Number Density
       Quality Bit Flag and Volumetric Mixing Ratio Quality Bit Flag.  
       These values are actually written into the hexidecimal format.  
       This means that code and users must be careful in reading and/or 
       writing and/or working with these data values. Because these 
       are hexidecimal values, you must read them as unsigned 16-bit
       integers.

NOTE:  The data described in this readme file were created on a Dec Alpha
       system.  Therefore the bytes are swaped in the binary data files.
       (These are the data sets that have the "NAT" in their names.  In
       more detail, these are the data files which have the "32-bit" in 
       their granule name (file name).) Therefore, if you plan to work
       with the SAGE II Native data sets, and you are planning to read the
       data on a Dec Alpha, you must comment out the "swap_endian" call
       line in the IDL, ".pro," programs before compiling and executing
       them.
        

5.1 SAGE I Aerosol Profiles Data Set

This data set is written in HDF.

FILE NAMING CONVENTION:
  sag1_aer_prf_yymm 
  where yy represents the year and mm represents the month.

VARIABLES:
All records and parameters within this data set have been defined, including 
their minimum and maximum values in the HDF file. The read software will 
display these values.

NOTES ON DATA:
There are 34 monthly data files in this data set dating from February 1979 
through November 1981. Every granule consists of 38 parameters per 
event/record.

Users must take note that when ordering data within the IMS database, 
the longitude values are expected to be stored in the -180 to +180 degree 
format. This experiment stores the longitude values in 0 to 360 degree format 
within the data files. Please keep track of this! This pertains to the 
SAGE I AEROSOL PROFILES Data Set ONLY!

INSTRUMENTATION:
This information is provided in the User's Guides provided by the data 
producer.

CONTACTS FOR DATA PRODUCTION INFORMATION:

Dr. William P. Chu
Atmospheric Science Division - Aerosol Research Branch
23A Langley Boulevard
NASA Largely Research Center
Hampton, Virginia 23681-2199
U.S.A.

Phone:    (757) 864-2675
FAX:      (757) 864-3671
E-Mail:   W.P.CHU@LaRC.NASA.GOV


5.2 SAGE II Aerosol Profiles Data Set

These data sets are available in HDF, ASCII and binary.  There are three data
sets at the Langley DAAC representing these data in different formats.

FILE NAMING CONVENTION FOR HDF DATA:
  sag2_aer_prf_yymm 
  where yy represents the year and mm represents the month.

FILE NAMING CONVENTION FOR ASCII DATA:
 aeryymm_ascii 
 where yy represents the year and mm represents the month.
 
FILE NAMING CONVENTION FOR BINARY DATA:
 aeryymm_32-bit 
 where yy represents the year and mm represents the month.
 
VARIABLES:
All records and parameters within this data set have been defined, including 
their minimum and maximum values in the HDF file. The read software will 
display these values.

NOTES ON DATA:
Currently, this data set dates from October 1984 through the present. This is 
an ongoing experiment. Every granule consists of 44 parameters per 
event/record.

NOTE 1:  The data producer has provided two additional years of data 
granules for this data set.  Of the two years, data granules dating 9306
through 9312 are being replaced with new files. The data producer has provided 
this explanation on the replacement of these six months. (09/06/95)

The current version of the SAGE II data was processed with the same SAGE II 
data processing algorithm as the previous version. The previous version was 
processed on the CDC Cyber machine while the current version has been 
processed on the migrated software to a DEC Alpha machine. There should be no 
fundamental difference between the two versions of the SAGE II data.

NOTE 2:  The data producer has reprocessed all data for this data set.  These
files have updated mirror calibration values.  The version of this data set is
5.931. (11/11/97)

NOTE 3: The ASCII and binary data sets were added to the SAGE II collection.
(01/01/98)

INSTRUMENTATION:
This information is provided in the User's Guides provided by the data 
producer and  available from the Langley DAAC Science, Users and Data Services
Office.

CONTACTS FOR DATA PRODUCTION INFORMATION:

Dr. William P. Chu
Atmospheric Science Division - Aerosol Research Branch
23A Langley Boulevard
NASA Largely Research Center
Hampton, Virginia 23681-2199
U.S.A.

Phone:    (757) 864-2675
FAX:      (757) 864-3671
E-Mail:   W.P.CHU@LaRC.NASA.GOV


5.3 SAGE II Ozone Profiles Data Set

These data sets are available in HDF, ASCII and binary.  There are three data
sets at the Langley DAAC representing these data in different formats.

FILE NAMING CONVENTION FOR HDF DATA:
  sag2_ozn_prf_yymm 
  where yy represents the year and mm represents the month.

FILE NAMING CONVENTION FOR ASCII DATA:
  oznyymm_ascii 
  where yy represents the year and mm represents the month.
  
FILE NAMING CONVENTION FOR BINARY DATA:
  oznyymm_32-bit 
  where yy represents the year and mm represents the month.

VARIABLES:
All records and parameters within this data set have been defined, including 
their minimum and maximum values in the HDF file. The read software will 
display these values.

There is a parameter defined in the data set called "Number Density" where the 
minimum value is set to 0. The maximum value is defined as 100000000376832.0. 
This number was originally defined as being 10.0e14 when the data set was 
created on the DEC Alpha (a 64-bit machine). However, as the data were 
converted from a 64-bit number representation to a 32-bit representation, the 
precision of the data value was dependent upon the machine where the data were 
developed.

NOTES ON DATA:
Currently, this data set dates from October 1984 through the present. This is 
an ongoing data set. Every granule consists of 33 parameters per event/record.

Of these data granules on-line, 11 monthly files last event consist of the 
first event of the following data months. Due to merging requirements, this 
event will not be repeated in the next monthly data file. The following data 
months (for their last event/record) contain the first event/record for the 
next month: 8410, 8512, 8608, 8612, 8803, 8807, 8809, 8812, 9001, 9002, and 
9112. These months can be recognized when ordering data through the Langley 
DAAC in the granule details window.

NOTE 1:  The following statement is from the data provider pertaining to the 
data granules dated 1995 through 1996: (02/13/97) 

"The code which produces version 5.93 of the SAGE II data is no longer being 
maintained since we are working on upgrading to a newer version.  Until this 
new version is released, we will continue to process data at the version 5.93 
revision level and distribute it via the DAAC.  Users who have previously 
acquired version 5.93 ozone data for 1995 and 1996 are cautioned against using 
the data at altitudes above 50km."

The data currently available from the Langley DAAC have been reprocessed. 
Those values that were above 50km now have fill values in those places.

NOTE 2:  The data producer has reprocessed all data for this data set.  These
files have updated mirror calibration values.  The version of this data set is
5.931. (11/11/97)

NOTE 3: The ASCII and binary data sets were added to the SAGE II collection.
(01/01/98).

INSTRUMENTATION:
This information is provided in the User's Guides provided by the data 
producer and available from the Langley DAAC Science, Users and Data Services
Office.

CONTACTS FOR DATA PRODUCTION INFORMATION:

Dr. William P. Chu
Atmospheric Science Division - Aerosol Research Branch
23A Langley Boulevard
NASA Largely Research Center
Hampton, Virginia 23681-2199
U.S.A.

Phone:    (757) 864-2675
FAX:      (757) 864-3671
E-Mail:   W.P.CHU@LaRC.NASA.GOV


5.4 SAGE II Nitrogen Dioxide Profiles Data Set

These data sets are written in HDF, ASCII and binary.  There are three data
sets at the Langley DAAC representing these data in different formats.  

These data sets consist of only sunset data.

FILE NAMING CONVENTION FOR HDF DATA:
  sag2_no2_prf_yymm 
  where yy represents the year and mm represents the month.
  
FILE NAMING CONVENTION FOR ASCII DATA:
  no2yymm_ascii 
  where yy represents the year and mm represents the month.
 
FILE NAMING CONVENTION FOR BINARY DATA:
  no2yymm_32-bit 
  where yy represents the year and mm represents the month.

VARIABLES:
All records and parameters within this data set have been defined, including 
their minimum and maximum values in the HDF file. The read software will 
display these values.

There is a parameter defined in the data set called "Number Density" where the 
minimum value is set to 0.0. The maximum value is defined as 99999997952.0. 
This number was originally defined as being 10.0e10 when the data set was 
created on a DEC Alpha (a 64-bit machine). However, as the data was converted 
from a 64-bit number representation to a 32-bit representation, the precision 
of the data value was dependent upon the machine where the data were developed.

NOTES ON DATA:
Currently, this data set dates from October 1984 through the present. This is 
an ongoing data set. Every granule consists of 34 parameters per event/record.

Of these monthly data files, 11 monthly files last event consist of the first 
event of the following data months. Due to merging requirements, this event 
will not be repeated in the next monthly data file. The following data months 
(for their last event/record) contain the first event/record for the next 
month: 8410, 8512, 8608, 8612, 8803, 8807, 8809, 8812, 9001, 9002, and 9112. 
These months can be recognized when ordering data through the Langley DAAC in 
the granule details window.

NOTE 1:  The data producer has asked the DAAC to pass the following information 
on to users. (09/06/95)

A possible instrument drift in the SAGE II data as been identified in the one 
of the narrow bandpass channel used for the NO2 measurements. The drift is 
slow over the last ten years, and could potentially produce an artificial trend 
in the long term NO2 records. The users should be cautioned when using the 
SAGE II NO2 data for long term trend studies.

NOTE 2:  The data producer has reprocessed all data for this data set.  These
files have updated mirror calibration values.  The version of this data set is
5.931. (11/11/97)

NOTE 3: The ASCII and binary data sets were added to the SAGE II collection.
(01/01/98)

INSTRUMENTATION:
This information is provided in the User's Guides provided by the data 
producer and available from the Langley DAAC Science, Users and Data Services
Office.

CONTACTS FOR DATA PRODUCTION INFORMATION:

Dr. William P. Chu
Atmospheric Science Division - Aerosol Research Branch
23A Langley Boulevard
NASA Largely Research Center
Hampton, Virginia 23681-2199
U.S.A.

Phone:    (757) 864-2675
FAX:      (757) 864-3671
E-Mail:   W.P.CHU@LaRC.NASA.GOV


5.5 SAGE II Water Vapor Profiles Data Set

This data set is written in HDF.

FILE NAMING CONVENTION:
  sag2_h2o_prf_yymm 
  where yy represents the year and mm represents the month.
  
VARIABLES:
All records and parameters within this data set have been defined, including 
their minimum and maximum values in the HDF file. The read software will 
display these values.

There is a parameter defined in the data set called "Number Density" where 
the minimum value is set to 0. The maximum value is defined as 
100000000376832.0. This number was originally defined as being 10.0e14 when 
the data set was created on the DEC Alpha (a 64-bit machine). However, as the 
data was converted from a 64-bit number representation to a 32-bit 
representation, the precision of the data value was dependent upon the machine 
where the data were developed.

NOTES ON DATA:
There are 65 monthly data files in this data set dating from January 1986 
through May 1991. This is an ongoing data set. Every granule consists of 33 
parameters per event/record.

INSTRUMENTATION:
This information is provided in the User's Guides provided by the data 
producer and are available from the Langley DAAC Science, Users and Data
Services Office.

CONTACTS FOR DATA PRODUCTION INFORMATION:

Dr. William P. Chu
Atmospheric Science Division - Aerosol Research Branch
23A Langley Boulevard
NASA Largely Research Center
Hampton, Virginia 23681-2199
U.S.A.

Phone:    (757) 864-2675
FAX:      (757) 864-3671
E-Mail:   W.P.CHU@LaRC.NASA.GOV

6.0 Implementation Notes

6.1 HDF IMPLEMENTATION
 
The read_sage.c program is able to read SAGE I Aerosol Profiles, SAGE II 
Aerosol Profiles, SAGE II Ozone Profiles, SAGE II Nitrogen Dioxide Profiles, 
and SAGE II Water Vapor Profiles. When executed, the program prompts the user 
for the type of data it is expected to be reading. The program will then print 
out a list of the parameters that are included in each data set. All of the
parameters the user selects will be printed out for every record/event.  A 
description of these parameters are located in the User's Guide that is 
specific to each data set. Currently, users must contact Langley DAAC Users 
Services for copies of these guides (see section 1 for information on how to 
contact User Services).  

Along with these parameters, the program will print out additional information 
such as the Event Date, Event Time, Latitude, Longitude, Event Type (Sunrise or 
Sunset), and Minimum Altitude (this is the first value of the Geometric Altitude
values for each record/event). The read program creates a report file with the 
name of the input data file with an extension of ".rpt." This report file is 
written to the current working directory.

Once the user types the executable name at the command line, read_sage,
the user will see the following appear on the screen:

command> read_sage


   *****************************************************
   *                                                   *
   *     SAGEs I & II HDF Read Program Version 7.0     *
   *                                                   *
   *                                                   *
   *  This sample read program currently reads the     *
   *  following data sets:                             *
   *                                                   *
   *             SAGE I Aerosol Profiles               *
   *             SAGE II Aerosol Profiles              *
   *             SAGE II Ozone Profiles                *
   *             SAGE II Nitrogen Dioxide Profiles     *
   *             SAGE II Water Vapor Profiles          *
   *                                                   *
   *                                                   *
   *                 January 26, 1999                  *
   *****************************************************





This is a list of all SAGE experiments.

  1.  SAGE I Aerosol Profiles
  2.  SAGE II Aerosol Profiles
  3.  SAGE II Ozone Profiles
  4.  SAGE II Nitrogen Dioxide Profiles
  5.  SAGE II Water Vapor Profiles

Enter type of experiment (1 thru 5) ... 4


Enter the full data path as well as the data name.
sag2_no2_prf_8410


In your output report file, do you want to include the 
file description?  Enter 1 for yes and 2 for no .... 1


Would you like to have the program write out all of the
parameters?  Enter Y for yes or N for no.  -->  n
 Item Number             Label

      1           Event Date (yymmdd.0)
      2           Event Time (hhmmss.0)
      3           Subtangent Latitude
      4           Subtangent Longitude
      5           Event Type (1.0 = sunset)
      6           Earth-Referenced Event Type (0.0 = sunrise 1.0 = sunset)
      7           Spacecraft Beta Angle
      8           Coded Time of Year (ddd.fract)
      9           NMC Temperature
     10           NMC Temperature Error
     11           NMC Altitude
     12           NMC Density
     13           Air Density Error
     14           NMC Temperature Correction for 5.0mb, 2.0mb, 1.0mb, and 0.4mb Level
     15           Met array Model Data Pointer

Please choose the numbers of the data items you wish to output.
Enter -1 to continue to next list or 0 to begin processing.

1
-1
 Item Number             Label

     16           Model Met Selection Code
     17           LaRC Processing Date (yymmdd.0)
     18           LaRC Processing Time (hhmmss.0)
     19           Mean Subtangent Altitude of Event Limb Calibration
     20           Scan Mirror Calibration Code Date
     21           Quality Factor 453nm
     22           Quality Factor 448nm
     23           Latitude Corresponding to Altitude
     24           Longitude Corresponding to Altitude
     25           Time Span of Data from Level 1 through 70
     26           Geometric Altitude
     27           Corresponding Pressure
     28           Corresponding Temperature
     29           Number Density
     30           Volumetric Mixing Ratio

Please choose the numbers of the data items you wish to output.
Enter -1 to continue to next list or 0 to begin processing.

-1
 Item Number             Label

     31           Number Density Error (% of value)
     32           Volumetric Mixing Ratio Error (% of value)
     33           Number Density Quality Bit Flag
     34           Volumetric Mixing Ratio Quality Bit Flag

Please choose the numbers of the data items you wish to output.
Enter -1 to continue to next list or 0 to begin processing.

34
0



The following is a list of the parameters you have selected:

 1    Event Date (yymmdd.0)
 34    Volumetric Mixing Ratio Quality Bit Flag


Would you like to make a new selection of these parameters or
would you like this program to exit the selection process and
begin retrieving the data? 
Enter Y for yes to retrieve data or N for no make a new selection.   --> y




Reading labels....


There are 115 records/number of events in the HDF file.
NOTE:  This will take some time to write out the report file.


Reading data, Please wait ...

             ... and wait ...

             ... and wait ...


@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                                             @
@ This program has completed and has created an output report @
@ file called sag2_no2_prf_8410.rpt in your current          @
@ working directory.                                          @
@                                                             @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


6.2 ASCII IMPLEMENTATION

Once the program is invoked, the user will be prompted for the name of the input
file. The name of the outpur file will be displayed.  A custom menu will then be
displayed.  When the user selects one of the options, a sub-menu will be
displayed from which the user can select actual parameters.


AEROSOL PROFILES:

            A custom menu will be displayed from which
            you may select all or some of the parameters. The output
            will be written to the output file.
            

                   Customized Output Menu
                   ======================                           
  1...DUMP ALL PARAMETERS
  2...REFERENCE DATA
      Event Date, Time, Type, Earth-Reference Event Type,
      Subtangent Latitude and Longitude,
      Spacecraft Beta Angle, Coded Time of Year
  3...NMC METEOROLOGICAL DATA
      Temp., Temp. Error, Geom. Alt., Air Density, Air Density
      Error, Correc. Values, Data Flag, Data Index Ptr
      Model Met Sel. Code, Revision Date of LaRc Met. Model
  4...NASA/LARC PROCESSING INFORMATION
      LaRC Processing Revision Level, Trans. Revision Level,
      Inversion Revision Level,Event Tag, Date, Time
      Mean Subtangent Altitude for Event Limb Calibration
  5...EVENT GROUND-TRACK SLEW DATA
      Subtangent Altitude, Corresponding Latitude,
      Corresp.Longitude, Time span of Data for Levels 1-70
  6...ALTITUDE AND METEOROLOGICAL DATA FOR PROFILE ARRAYS
      Geometric Altitude, Corresponding Pressure, Temperature,
     Scan Mirror Calibration Code
  7...CHANNEL OPTICAL DEPTH PROFILE QUALITY ESTIMATIONS
      1020, 525, 453 and 385 nm Wavelength Quality Factors
  8...RAYLEIGH EXTINCTION PROFILES
      1020, 525, 453, 385 nm Extinction Profiles
  9...AEROSOL PROFILES
      1020, 525, 453 and 385 Extinction Values
      1020, 525, 453 and 385 Extinction Errors
  0...To Exit
                  

OZONE PROFILES:
   
          A custom menu will be displayed from which
          you may select all or some of the parameters. The output
          will be written to the output file.
  
           
                    Customized Output Menu
                    ======================
  1...DUMP ALL PARAMETERS
  2...REFERENCE DATA
      Event Date, Time, Type, Earth-Reference Event Type,
      Subtangent Latitude and Longitude,
      Spacecraft Beta Angle, Coded Time of Year
  3...NMC METEOROLOGICAL DATA
      NMC Temperature, Error, Correction Values, Altitude,
      Air Density, Density Error, Met Array Model Data Pointer,
      Model Met Selection Code, Revision Date of LaRc Met Model
  4...NASA/LARC PROCESSING INFORMATION
      LaRC Processing Revision Level, Date, Time,
      Mean Subtangent Altitude for Event Limb Calibration,
      Scan Mirror Calibration Code Date, Quality Factor,
      Float-point Data Fill Number
  5...EVENT GROUND-TRACK SLEW DATA
      Latitude, Longitude Corresponding to Altitude,
      Time Span of Data from Level 1 through 70
  6...ALTITUDE AND METEOROLOGICAL DATA FOR PROFILE ARRAYS
      Geometric Altitude, Corresponding Pressure, Temperature
  7...OZONE PROFILES
      Number Density, Error, Volumetric Mixing Ratio, Error,
      Number Density Quality Bit Flag,
      Volumetric Mixing Ratio Quality Bit Flag,
      Integer Data Fill Number

  0...To Exit
        

NO2 PROFILES:    

        A custom menu will be displayed from which
        you may select all or some of the parameters. The output
        will be written to the output file.

                   Customized Output Menu
                   ======================
  1...DUMP ALL PARAMETERS
  2...REFERENCE DATA
      Event Date, Time, Type, Earth-Reference Event Type,
      Subtangent Latitude and Longitude,
      Spacecraft Beta Angle, Coded Time of Year
  3...NMC METEOROLOGICAL DATA
      NMC Temperature, Error, Correction Values, Altitude,
      Air Density, Density Error, Met Array Model Data Pointer,
      Model Met Selection Code, Revision Date of LaRc Met Model
  4...NASA/LARC PROCESSING INFORMATION
      LaRC Processing Revision Level, Date, Time,
      Mean Subtangent Altitude for Event Limb Calibration,
      Scan Mirror Calibration Code Date, 453 nm Quality Factor
      448 nm Quality Factor
  5...EVENT GROUND-TRACK SLEW DATA
      Latitude, Longitude Corresponding to Altitude,
      Time Span of Data from Level 1 through 60
  6...ALTITUDE AND METEOROLOGICAL DATA FOR PROFILE ARRAYS
      Geometric Altitude, Corresponding Pressure, Temperature
  7...NO2 PROFILES
      Number Density, Error, Volumetric Mixing Ratio, Error,
      Number Density Quality Bit Flag,
      Volumetric Mixing Ratio Quality Bit Flag

  0...To Exit          
      

6.3 BINARY IMPLEMENTATION

Once the IDL software has been executed, the user will be prompted for the 
name of the data file.


AEROSOL PROFILES:

A customized menu has been provided to enable the user to select parameters. 


                    Customized Output Menu
                   ========================

This data contains 58 parameters.

To output all parameters enter a

To select parameters enter s

: s
       1  Event Date(yymmdd.0)
       2  Event Time(hhmmss.0)
       3  Subtangent Latitude
       4  Subtangent Longitude
       5  Spacecraft-Referenced Event Type(0.0 = sunrise, 1.0 = sunset)
       6  Earth-Referenced Event Type(0.0 = sunrise, 1.0 = sunset)
       7  Spacecraft Beta Angle
       8  Coded Time of Year(ddd.fract)
       9  NMC Temperature
      10  NMC Temperature Error
      11  Geometric Altitude
      12  Air Density
      13  Air Density Error
      14  NMC Temp. Correction Values for 5.0 Millibar Levels
      15  NMC Temp. Correction Values for 2.0 Millibar Levels
      16  NMC Temp. Correction Values for 1.0 Millibar Levels
      17  NMC Temp. Correction Values for 0.4 Millibar Levels
      18  Met. Data not Complete Flag(0=complete,1=incomplete)
      19  Data Array Index Pointer

Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):

To begin processing enter p
To continue to next list enter c
: c
      20  Model Met. Data Selection Code
      21  Revision Date of LaRC Met. Model
      22  LaRC Driver Revision Level
      23  LaRC Transmission Revision Level
      24  LaRC Inversion Revision Level
      25  LaRC Event Tag
      26  LaRC Processing Date
      27  LaRC Processing Time
      28  Mean Subtangent Altitude for Event Limb Calibration(km)
      29  Subtangent Altitude
      30  Latitude Corresponding to Altitude
      31  Longitude Corresponding to Altitude
      32  Time Span of Data from Level 1 through 70
      33  Geometric Altitude(km)
      34  Corresponding Pressure(millibars)
      35  Corresponding Temperature
      36  Scan Mirror Calibration Code
      37  1020 nm Wavelength Quality Factor
      38  525 nm Wavelength Quality Factor
      39  453 nm Wavelength Quality Factor

Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):

To begin processing enter p
To continue to next list enter c
: c
      40  385 nm Wavelength Quality Factor
      41  1020 nm Rayleigh Extinction
      42  1020 nm Rayleigh Extinction Error
      43  525 nm Rayleigh Extinction
      44  525 nm Rayleigh Extinction Error
      45  453 nm Rayleigh Extinction
      46  453 nm Rayleigh Extinction Error
      47  385 nm Rayleigh Extinction
      48  385 nm Rayleigh Extinction Error
      49  1020 nm  Extinction
      50  1020 nm Extinction Error
      51  525 nm Extinction
      52  525 nm Extinction Error
      53  453 nm Extinction
      54  453 nm Extinction Error
      55  385 nm Extinction
      56  385 nm Extinction Error
      57  1020 nm Extinction Ratio
      58  1020 nm Extinction Ratio Error

Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):


OZONE PROFILES:

A customized menu has been provided to enable the user to select parameters.

                   Customized Output Menu
                   =======================

To output all parameters enter a
To select parameters enter s
: s
       1  Event Date (yymmdd.0)
       2  Event Time (hhmmss.0)
       3  Subtangent Latitude
       4  Subtangent Longitude
       5  Spacecraft-Referenced Event Type
       6  Earth-Referenced Event Type
       7  Spacecraft Beta Angle
       8  Coded Time of Year
       9  NMC Temperature
      10  NMC Temperature Error
      11  Geometric Altitude(meters)
      12  Air Density
      13  Air Density Error
      14  Temp. Correction Values for 5,2,1, & 0.4 Millibar Levels
      15  Data Array Index Pointer
      16  Model Met. Data Selection Code
      17  Revision Date of LaRC Met. Model
Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):

To begin processing enter p
To continue to next list enter c
: c
      18  LaRC Processing Revision Level
      19  LaRC Processing Date
      20  LaRC Processing Time
      21  Mean Subtangent Altitude for Event Limb Calibration(km)
      22  Scan Mirror Calibration Code Date
      23  600 nm Wavelength Processing Quality Factor
      24  Latitude
      25  Longitude
      26  Time Span of Data from Level 1 through 70(secs.)
      27  Geometric Altitude(km)
      28  Corresponding Pressure(millibars)
      29  Corresponding Temperature
      30  Number Density
      31  Volumetric Mixing Ratio
      32  Number Density Error
      33  Volumetric Mixing Ratio Error
      34  Number Density Quality Bit Flag
      35  Volumetric Mixing Ratio Quality Bit Flag
Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):


NO2 PROFILES:

A customized menu has been provided to enable the user to select parameters.

                   Customized Output Menu
                   =======================

To output all parameters enter a
To select parameters enter s
: s
       1  Event Date(yymmdd.0)
       2  Event Time(hhmmss.0)
       3  Subtangent Latitude
       4  Subtangent Longitude
       5  Spacecraft-Referenced Event Type
       6  Earth-Referenced Event Type
       7  Spacecraft Beta Angle
       8  Coded Time of Year
       9  NMC Temperature
      10  NMC Temperature Error
      11  Geometric Altitude(meters)
      12  Air Density
      13  Air Density Error
      14  Temp. Correction Values for 5,2,1, & 0.4 Millibar Levels
      15  Data Array Index Pointer
      16  Model Met. Data Selection Code
      17  Revision Date of LaRC Met. Model
Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):

To begin processing enter p
To continue to next list enter c
: c
      18  LaRC Processing Revision Level
      19  LaRC Processing Date
      20  LaRC Processing Time
      21  Mean Subtangent Altitude for Event Limb Calibration(km)
      22  Scan Mirror Calibration Code Date
      23  453 nm Wavelength Quality Factor
      24  448 nm Wavelength Quality Factor
      25  Latitude
      26  Longitude
      27  Time Span of Data from Level 1 through 70(secs.)
      28  Geometric Altitude(km)
      29  Corresponding Pressure(millibars)
      30  Corresponding Temperature
      31  Number Density
      32  Volumetric Mixing Ratio
      33  Number Density Error
      34  Volumetric Mixing Ratio Error
      35  Number Density Quality Bit Flag
      36  Volumetric Mixing Ratio Quality Bit Flag
Please choose the numbers of the data items you wish to output.
Enter -1 when selection is completed
Enter selection number (each number followed by <CR>):

           

Updated April 07, 1999        LD_008_021_004_00_00_0_19990407