SCAR-B Airborne Visible/InfraRed Imaging Spectrometer [AVIRIS]
                                    Readme

1.0 Introduction:

This file contains information about the SCAR-B AVIRIS data products and
about how to use the hyperspectral imaging package.  For much of
the past decade, hyperspectral imaging has been an area of active
research and development.  With the recent appearance of commercial
airborne hyperspectral imaging systems, hyperspectral imaging is 
poised to enter the mainstream of remote sensing.  This document
aims to provide a working knowledge about how to use the hyperspectral
imaging tool with this data set.

This document also includes the following sections:

2.0 Provides information on the data set.
3.0 Describes the format and/or packaging of the data.
4.0 Provides information on the "Hyperspectral Imaging" package.

    If users have questions, please contact the Langley DAAC Science, Users
    and Data Services Office at:

    EOSDIS Langley DAAC
    Science, Users and Data Services Office
    NASA Langley Research Center
    Mail Stop 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
    URL:      http://eosweb.larc.nasa.gov

2.0 Data Set description.

    The AVIRIS instrument contains 224 different detectors, each with a 
    wavelength sensitive range [also know as spectral bandwidth] of
    approximately 10 nanometers[nm], allowing it to cover the entire
    range between 380nm and 2500nm.  When the data from each detector 
    is plotted on a graph, it yields a spectrum.  Comparing the
    resulting spectrum with those of known substances reveals information
    about the composition of the area being viewed by the instrument.

2.1 Data Characteristics
    
    Units:   (W/cm^2/nm/sr)

    Spectral:
            Wavelength range                 400 to 2500 nm
            Sampling                         <10 nm
            Spectral response (fwhm)         10 nm nominal
            Calibration                      <1nm

    Radiometric:
            Radiometric Range                0 to maximum lambertion radiance
            Sampling                         ~ 1 dn noise rms
            Absolute calibration             >= 96%
            Interflight stability            >= 98%
            Noise                            Exceeding nedl/snr requirement
            Polarization Sensitivity         <= 1%

    Geometric:
            Field of view                    30 degrees (11 km)
            Instantaneous FOV                1.0 mrad (20 m)
            Calibration                      <=0.1 mrad
            Flight line length               10*80 km

2.2 Operational Characteristics

    Sensor:
            Imager type                      Whiskbroom scanner (12 hz)
            Dispersion                       Four grating spectrometers (A,B,C,D)
            Detection                        224 detectors (32, 64, 64, 64) Si&InSb
            Digitization                     12 bits
            Data rate                        20.4 mbits/second
            Spectrum rate                    7300 spectra/second
            Data capacity                    >10 gigabytes (>8,000 km^2)
            Launches                         >40 per year

2.3 Instrumentation description.

    "AVIRIS" is an acronym for the "Airborne Visible/InfraRed Imaging
    Spectrometer".  "AVIRIS" is a world class instrument in the realm
    of Earth Remote Sensing.  It is a unique optical sensor that delivers
    calibrated images of the upwelling spectral radiance in 224 contiguous 
    spectral channels [also called bands] with wavelengths from 400 to
    2500 nanometers[nm].

3.0 Format and packaging.

    The files have been tarred into files such as "scar_b_aviris_8m0048_1.tar".
    The portion of the name which starts with "8m0048_1.tar" was the
    tape number that contained the raw data file.  These files hold the flight
    numbers that were obtained from the original flight tapes.  This tar
    file contains all of the 15 different files generated for each flight.
    They are:
    flightrun.ext
    [where the *.ext is described as]
    *.avhdr, *.gain, *.occ, *.post, *.pre, *.rcc, *.spc, *.brz, *.geo, *,log,
    *.drk1, *.drk2, *.eng, *.nav, *img

    To list the files on a particular tar file type in this command:
       tar tvf "tar file name"
    To extract the files on a particular tar file type in this command:
       tar xvf "tar file name"

    Here below is the tarfile name and the associated flight that is on it.
    To order the data you must determine which flight you want and then order
    the tarfile name that holds it.
TAR_FILE                         FLIGHT NUMBER
--------------------------------------------------
 scar_b_aviris_8m0048_1.tar  - f950816t01p02_r02
 scar_b_aviris_8m0049_1.tar  - f950816t01p02_r03a
 scar_b_aviris_8m0050_1.tar  - f950816t01p02_r03b
 scar_b_aviris_8m0051_1.tar  - f950816t01p02_r04
 scar_b_aviris_8m0052_1.tar  - f950818t01p02_r01a
 scar_b_aviris_8m0053_1.tar  - f950818t01p02_r01b
 scar_b_aviris_8m0054_1.tar  - f950818t01p02_r02a
 scar_b_aviris_8m0055_1.tar  - f950818t01p02_r02b
 scar_b_aviris_8m0056_1.tar  - f950818t01p02_r03a
 scar_b_aviris_8m0057_1.tar  - f950818t01p02_r03b
 scar_b_aviris_8m0218_1.tar  - f950818t01p02_r04a   this tar file was redone.
 scar_b_aviris_8m0219_1.tar  - f950818t01p02_r04b   this tar file was redone.
 scar_b_aviris_8m0220_1.tar  - f950820t01p02_r03
 scar_b_aviris_8m0060_1.tar  - f950820t01p02_r01
 scar_b_aviris_8m0061_1.tar  - f950820t01p02_r02
 scar_b_aviris_8m0220_1.tar  - f950820t01p02_r03    this tar file was redone.
 scar_b_aviris_8m0063_1.tar  - f950820t01p02_r04
 scar_b_aviris_8m0064_1.tar  - f950820t01p02_r05
 scar_b_aviris_8m0065_1.tar  - f950823t01p02_r01
 scar_b_aviris_8m0066_1.tar  - f950823t01p02_r02a
 scar_b_aviris_8m0067_1.tar  - f950823t01p02_r02b
 scar_b_aviris_8m0068_1.tar  - f950823t01p02_r03a
 scar_b_aviris_8m0069_1.tar  - f950823t01p02_r03b
 scar_b_aviris_8m0070_1.tar  - f950823t01p02_r04a
 scar_b_aviris_8m0071_1.tar  - f950823t01p02_r04b
 scar_b_aviris_8m0072_1.tar  - f950823t01p02_r05
 scar_b_aviris_8m0073_1.tar  - f950823t01p02_r06
 scar_b_aviris_8m0074_1.tar  - f950825t01p02_r02
 scar_b_aviris_8m0075_1.tar  - f950825t01p02_r03
 scar_b_aviris_8m0076_1.tar  - f950825t01p02_r04a
 scar_b_aviris_8m0077_1.tar  - f950825t01p02_r04b
 scar_b_aviris_8m0078_1.tar  - f950825t01p02_r05
 scar_b_aviris_8m0221_1.tar  - f950825t01p02_r06    this tar file was redone.
 scar_b_aviris_8m0081_1.tar  - f950825t01p02_r08a
 scar_b_aviris_8m0082_1.tar  - f950825t01p02_r08b
 scar_b_aviris_8m0083_1.tar  - f950825t01p02_r09
 scar_b_aviris_8m0084_1.tar  - f950827t01p02_r01
 scar_b_aviris_8m0085_1.tar  - f950827t01p02_r02
 scar_b_aviris_8m0086_1.tar  - f950827t01p02_r03
 scar_b_aviris_8m0222_1.tar  - f950827t01p02_r04    this tar file was redone.
 scar_b_aviris_8m0088_1.tar  - f950827t01p02_r05
 scar_b_aviris_8m0089_1.tar  - f950827t01p02_r06
 scar_b_aviris_8m0090_1.tar  - f950827t01p02_r07
 scar_b_aviris_8m0224_1.tar  - f950827t01p02_r08a   this tar file was redone.
 scar_b_aviris_8m0092_1.tar  - f950827t01p02_r08b
 scar_b_aviris_8m0093_1.tar  - f950830t01p02_r01a
 scar_b_aviris_8m0094_1.tar  - f950830t01p02_r01b
 scar_b_aviris_8m0095_1.tar  - f950830t01p02_r02a
 scar_b_aviris_8m0096_1.tar  - f950830t01p02_r02b
 scar_b_aviris_8m0097_1.tar  - f950830t01p02_r03a
 scar_b_aviris_8m0098_1.tar  - f950830t01p02_r03b
 scar_b_aviris_8m0099_1.tar  - f950830t01p02_r04a
 scar_b_aviris_8m0100_1.tar  - f950830t01p02_r04b
 scar_b_aviris_8m0101_1.tar  - f950830t01p02_r05
 scar_b_aviris_8m0102_1.tar  - f950901t02p01_r06
 scar_b_aviris_8m0103_1.tar  - f950901t02p01_r07
 scar_b_aviris_8m0104_1.tar  - f950901t02p01_r08
 scar_b_aviris_8m0105_1.tar  - f950901t02p01_r09
 scar_b_aviris_8m0106_1.tar  - f950901t02p01_r10
 scar_b_aviris_8m0107_1.tar  - f950904t01p03_r01
 scar_b_aviris_8m0108_1.tar  - f950904t01p03_r02a
 scar_b_aviris_8m0109_1.tar  - f950904t01p03_r03a
 scar_b_aviris_8m0110_1.tar  - f950904t01p03_r04a
 scar_b_aviris_8m0111_1.tar  - f950904t01p03_r05
 scar_b_aviris_8m0112_1.tar  - f950904t01p03_r06
 scar_b_aviris_8m0113_1.tar  - f950904t01p03_r07a
 scar_b_aviris_8m0114_1.tar  - f950904t01p03_r07b
 scar_b_aviris_8m0115_1.tar  - f950907t01p02_r01
 scar_b_aviris_8m0116_1.tar  - f950907t01p02_r02
 scar_b_aviris_8m0117_1.tar  - f950907t01p02_r03
 scar_b_aviris_8m0118_1.tar  - f950907t01p02_r05a
 scar_b_aviris_8m0223_1.tar  - f950907t01p02_r06a   this tar file was redone.
 scar_b_aviris_8m0120_1.tar  - f950907t01p02_r06b
 scar_b_aviris_8m0121_1.tar  - f950907t01p02_r07a
 scar_b_aviris_8m0122_1.tar  - f950907t01p02_r08
 scar_b_aviris_8m0123_1.tar  - f950911t01p02_r01
 scar_b_aviris_8m0124_1.tar  - f950911t01p02_r03
 scar_b_aviris_8m0125_1.tar  - f950911t01p02_r04
 scar_b_aviris_8m0126_1.tar  - f950911t01p02_r05
 scar_b_aviris_8m0127_1.tar  - f950911t01p02_r06
 scar_b_aviris_8m0128_1.tar  - f950911t01p02_r07
 scar_b_aviris_8m0129_1.tar  - f950911t01p02_r08
 scar_b_aviris_8m0130_1.tar  - f950911t01p02_r09
 scar_b_aviris_8m0131_1.tar  - f950911t01p02_r10
 scar_b_aviris_8m0132_1.tar  - f950911t01p02_r11
 scar_b_aviris_8m0133_1.tar  - f950911t01p02_r12
 scar_b_aviris_8m0134_1.tar  - f950911t01p02_r13
 scar_b_aviris_8m0135_1.tar  - f950911t01p02_r14
 scar_b_aviris_8m0136_1.tar  - f950911t01p02_r15
 scar_b_aviris_8m0137_1.tar  - f950911t01p02_r16
 scar_b_aviris_8m0138_1.tar  - f950911t01p02_r17
 scar_b_aviris_8m0139_1.tar  - f950911t01p02_r18
 scar_b_aviris_8m0140_1.tar  - f950911t01p02_r19



4.0 Provides information on the "Hyperspectral Imaging" package.

    There are several commercial packages available for plotting Hyperspectral
    data, such as the Interactive Data Language [IDL] "ENVI" package.  We used
    a free copy of the "TNTlite" package obtained from MicroImages, Inc.
    If you do use The "TNTlite Geospatial Analysis" Tool to plot image [*.img]
    and browse [*.brz] files, the navigation [*.nav] file must also be available.
    Once you have obtained your copy of the "TNTlite Geospatial Analysis" Tool
    install it according to instructions by the vendor.  The "TNTlite" package
    can be ordered from the following address:

    MicroImages, Inc.
    201 N. 8th Street
    Lincoln, NE. 68508-1347 - USA

    http://www.microimages.com


    Here enclosed are some notes that we compiled about how to import and plot
    the "AVIRIS" "*img" and "*.brz" data files when we ran the "TNTlite" package.
    The following instructions will describe how to run the software after the
    installation of the "MicroImages, Inc." package:

    You need to create a file in the directory were you installed the software.
    This file will hold the data files that you will import into the "TNTlite"
    package.  This is part of the procedure for getting your data "*.img"
    files into the package.
    Make a file such as "file.rvc".  The "rvc" extension is necessary for this
    to work.  Now to begin the program type in the name "tntmips".  This will
    start the program running.  You then see a menu bar that displays the title
    "TNTlite 6.1 Serial # ......." from this menu select the "Process bar".
    Then from this menu select the "Import/Export (old)" option.  This will
    send you to the next bar menu "Import/Export." from here select the
    "AVIRIS" data set.  The next bar menu is the "Import Raster" option select
    97 from the "AVIRIS" type button then from the top select the "Input File"
    option. This takes you to the next bar menu "File Selection" select a
    "*.img" file then [ok]. From the next bar menu double click on the "*.nav"
    file then [ok], then back to the "Import Raster" menu select the "Import"
    bar on the bottom.  Then you will double click "<newfile>" and get a menu
    for "New Project File". Next in the name box type in your "filename" but
    leave off the ".rvc" extension, then enter [ok].  Next select the =>>
    arrow buttons for the data you wish written to the file and then hit [ok]
    to select it. Do the next =>> button until you have selected all the data
    you want, once you are done hit the cancel button. The Process Status
    window will then load data into your "file.rvc".  Then close out all menu
    windows except the first one and return to it "TNTlite 6.1 Serial 
    # ......." and select the following:
    "Process/Raster/Hyperspectral"
    Then from the "Hyperspectral Analysis" window select the "File" button to
    select the open "Hyperspectral Image" window and from here select the file
    with the ".rvc" extension then [ok], from this point on you should be able
    to plot the data.