========================================================================= AVIRIS Distribution Document 20160614 SEND COMMENTS TO sarah.r.lundeen@jpl.nasa.gov or robert.o.green@jpl.nasa.gov Additional information may be found on http://aviris.jpl.nasa.gov -------------------------------------------------------------------------- This document describes the data products and contents of an AVIRIS delivery. All downloaded files are in a tar.gz file. Windows Users: ============= Download the GZIP and TAR executables from the AVIRIS Flight Locator Tool Web Page (http://aviris.jpl.nasa.gov/alt_gulf/) into the same directory as the AVIRIS tar file. The following commands must be executed from a Windows Command Prompt window. - To decompress the AVIRIS tar file, type gzip -d "gzip file name (i.e. f100506t01p00r07.tar.gz)" - To list files (table-of-contents), type tar tvf "tar file name (i.e. f100506t01p00r07.tar)" - To extract files, in a command prompt window type tar xvf "tar file name" "extract file name (i.e. f100506t01p00r07.tar)" Mac/UNIX/LINUX Users: ==================== The following commands must be executed from a Terminal Window. - To decompress the AVIRIS tar file, type gzip -d "gzip file name (i.e. f100506t01p00r07.tar.gz)" - To list files (table-of-contents), type tar tvf "tar file name (i.e. f100506t01p00r07.tar)" - To extract files, in a command prompt window type tar xvf "tar file name" "extract file name (i.e. f100506t01p00r07.tar)" Each AVIRIS data product uses the following base name for naming convention (file name extensions are explained later in the document: fyymmddtnnpnnrnn ---------------- f: Airborne Flight. yy: The year of the airborne flight run (i.e. 10 represents 2010). mm: The month of the airborne flight run (i.e. 05 represents May). dd: The day of the airborne flight run (i.e. 22 represents 22nd day of the month). tnn: Legacy naming convention when AVIRIS used to record data onto VLDS tapes. pnn: Power cycle number (static number of 00). rnn: Airborne flight run number. v: Radiance software version number The AVIRIS L1 data products for a particular airborne flight run are organized in the following directory structure: /fyymmddtnnpnnrnnrdn_v | | *ortho.readme | AVIRIS_OrthoProcessing_Info.txt | fmmyyddtnnpnnrnnrdn_v_*gain | fmmyyddtnnpnnrnnrdn_v_*rcc | fmmyyddtnnpnnrnnrdn_v_*spc | fmmyyddtnnpnnrnnrdn_v_*eph | fmmyyddtnnpnnrnnrdn_v_*lonlat_eph | fmmyyddtnnpnnrnnrdn_v_*obs | fmmyyddtnnpnnrnnrdn_v_*obs.hdr | fmmyyddtnnpnnrnnrdn_v_*obs_ort | fmmyyddtnnpnnrnnrdn_v_*obs_ort.hdr | fmmyyddtnnpnnrnnrdn_v_*ort.plog | fmmyyddtnnpnnrnnrdn_v_*ort_glt | fmmyyddtnnpnnrnnrdn_v_*ort_glt.hdr | fmmyyddtnnpnnrnnrdn_v_*ort_igm | fmmyyddtnnpnnrnnrdn_v_*ort_igm.hdr | fmmyyddtnnpnnrnnrdn_v_*ort_img | fmmyyddtnnpnnrnnrdn_v_*ort_img.hdr The following types of files should be found: PER FLIGHT RUN: *gain multiplication factors, radiance to 16-bit integer, *rcc radiometric calibration coefficients, *spc spectral calibration file, *eph position data in a WGS-84/NAD83 UTM x,y,z coordinate system, *lonlat_eph position in WGS-84 longitude, latitude and elevation, *obs parameters relating to the geometry of the observation and illumination conditions in raw spatial format, *obs.hdr OBS image header file *obs_ort parameters relating to the geometry of the observation and illumination conditions rendered using the *_ort_glt lookup table, *obs_ort.hdr OBS_ORT image header file, *ort.plog generic data processing info *ortho.readme this file, *ort_glt geometric look-up table, *ort_glt.hdr GLT image header file, *ort_igm input geometry file, *ort_igm.hdr IGM image header file, *ort_img orthocorrected, scaled radiance image file, *ort_img.hdr ORT_IMG image header file. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- The AVIRIS L2 data products for a particular airborne flight run are organized in the following directory structure: /fyymmddtnnpnnrnn_rfl | | fmmyyddtnnpnnrnnrdn_corr_vn | fmmyyddtnnpnnrnnrdn_corr_vn.hdr | fmmyyddtnnpnnrnnrdn_h2o_v1 | fmmyyddtnnpnnrnnrdn_h2o_v1.hdr | *README_vn.txt The following types of files should be found: PER FLIGHT RUN: *README_vn.txt README file containing detailed description of L2 data products *corr_vn orthocorrected and atmospherically corrected reflectance data *corr_vn.hdr CORR image header file, *h2o_vn retrieved column water vapor and optical absorption paths for liquid h2o and ice, *h2o_vn.hdr H2O image header file. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- The AVIRIS CH4 data products for a particular airborne flight run are organized in the following directory structure: /fyymmddtnnpnnrnn_rfl | | fmmyyddtnnpnnrnnrdn_*cmfv | fmmyyddtnnpnnrnnrdn_*cmfv.hdr | fmmyyddtnnpnnrnnrdn_*cmfv_k=5* | fmmyyddtnnpnnrnnrdn_*cmfv_k=5.hdr | *readme.txt The following types of files should be found: PER FLIGHT RUN: *readme.txt README file containing detailed description of L2 data products, *cmfv retrieved methane mixing ratio lengths, *cmfv.hdr CMFV image header file, *cmfv_k=5 single band image of the retrieved methane mixing ration lengths, *cmfv_k=5.hdr CMFV_k=5 image header file. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- Contents of Files located in L1 directory ---------------------------------------------------------------------------- AVIRIS_OrthoProcessing_Info.txt Contents: Detailed description of AVIRIS orthorectification process. File type: ASCII. ---------------------------------------------------------------------------- *gain MULTIPLICATION FACTORS, RADIANCE TO 16-BIT INTEGER Contents: Multiplication factors to store radiance as 16-bit integers. File type: ASCII. Units: none. Format: Two columns: - Multiplication factor, - Channel number. Use: When each spectrum is divided by the factors in this file the 16-bit integers are converted to radiance in units of (micro- watts/cm^2/nm/sr). ---------------------------------------------------------------------------- *rcc RADIOMETRIC CALIBRATION COEFFICIENTS Contents: AVIRIS radiometric calibration coefficients and laboratory calibration uncertainty. File type: ASCII. Units: microwatts per centimeter_squared per nanometer per steradian per digitized_number. Format: Three columns: - Radiometric calibration coefficent, - Uncertainty in radiometric calibration coeff., - Channel number. ---------------------------------------------------------------------------- *spc SPECTRAL CALIBRATION FILE Contents: AVIRIS spectral calibration. File type: ASCII. Units: nanometers. Format: Five columns: - Wavelength center position, - Full width at half maximum for equivalent gaussian, - Uncertainty in wavelength center position, - Uncertainty in FWHM for equivalent gaussian, - Channel number. ---------------------------------------------------------------------------- *eph POSITION DATA (WGS-84/NAD83 UTM x,y,z coordinate system) Contents: The position data stored in a WGS-84/NAD83 UTM x,y,z coordinate system. The six values store the attitude (roll, pitch and heading) and position (x,y,z) for the sensor at the mid-point in each scan line. File type: BINARY double precision, floating point IEEE. ---------------------------------------------------------------------------- *lonlat_eph POSITION DATA (WGS-84 longitude, latitude and elevation) Contents: The position data stored in a WGS-84/NAD83 UTM x,y,z coordinate system. File type: BINARY double precision, floating point IEEE. ---------------------------------------------------------------------------- *ort_glt GEOMETRIC LOOKUP TABLE (GLT) Contents: Orthocorrected product with a fixed pixel size projected into a rotated UTM system that contains the information about which original pixel occupies which output pixel in the final product. Additionally, it is sign-coded to indicate if a certain output pixel is real (indicated by a positive value) or a nearest-neighbor infill pixel (indicated by a negative value). The GLT file contains two parameters: 1) sample number 2) original line number File type: BINARY 16-bit, integer, IEEE. Format: Band interleaved by line with dimensions (2 bands, N samples, N number of lines). ---------------------------------------------------------------------------- *ort_glt.hdr HEADER FILE FOR GEOMETRIC LOOKUP TABLE (GLT.HDR) DATA Contents: Format of each *ort_glt file. This file contains the number of lines, samples, channel, integer format, pixel size, scene elevation, UTM zone number and rotation angle information, etc. File type: ASCII ---------------------------------------------------------------------------- *ort_igm INPUT GEOMETRY FILE (IGM) Contents: Pixel location data for each radiance image cube. The IGM file data contain three parameters: 1) WGS-84 longitude (reported in decimal degrees) 2) WGS-84 latitude (reported in decimal degrees) 3) Estimated ground elevation at each pixel center (reported in meters) No map correction or resampling is applied to the radiance image cube; the IGM file only reports the surface location of the unadjusted pixel centers. File type: BINARY 64-bit double precision, floating point IEEE. Units: Band 1 - decimal degrees Band 2 - decimal degrees Band 3 - meters Format: Band interleaved by line with dimensions (3 bands, 677 samples, N number of lines). ---------------------------------------------------------------------------- *ort_igm.hdr HEADER FILE FOR INPUT GEOMETRY FILE (IGM) DATA Contents: Format of each *ort_igm file. This file contains the number of lines, samples, channel, integer format, etc. File type: ASCII ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- *obs OBSERVATION PARAMTER FILE (OBS) Contents: Observation parameter files in the raw spatial format; matches the corresponding unorthocorrected radiance image. The OBS file data contain eleven parameters: 1) path length (sensor-to-ground in meters) 2) to-sensor-azimuth (0 to 360 degrees clockwise from N) 3) to-sensor-zenith (0 to 90 degrees from zenith) 4) to-sun-azimuth (0 to 360 degrees clockwise from N) 5) to-sun-zenith (0 to 90 degrees from zenith) 6) solar phase (degrees between to-sensor and to-sun vectors in principal plane) 7) slope (local surface slope as derived from DEM in degrees) 8) aspect (local surface aspect 0 to 360 degrees clockwise from N) 9) cosine i (apparent local illumination factor based on DEM slope and aspect and to sun vector, -1 to 1) 10) UTC time (decimal hours for mid-line pixels) File type: BINARY 64-bit double-precision, floating point. Format: Band interleaved by pixel -------------------------------------------------------------------------------- *obs.hdr OBSERVATION PARAMETER FILE (OBS) Contents: Format of each AVIRIS *obs file. This file contains the number of lines, samples, channel, etc. File type: ASCII ---------------------------------------------------------------------------- *obs_ort ORTHOCORRECTED OBSERVATION PARAMTER FILE (OBS ORT) Contents: Observation parameter file that has been rendered using the GLT lookup table and matches the orthocorrected imagery. The OBS ORT file data contain eleven parameters: 1) path length (sensor-to-ground in meters) 2) to-sensor-azimuth (0 to 360 degrees clockwise from N) 3) to-sensor-zenith (0 to 90 degrees from zenith) 4) to-sun-azimuth (0 to 360 degrees clockwise from N) 5) to-sun-zenith (0 to 90 degrees from zenith) 6) solar phase (degrees between to-sensor and to-sun vectors in principal plane) 7) slope (local surface slope as derived from DEM in degrees) 8) aspect (local surface aspect 0 to 360 degrees clockwise from N) 9) cosine i (apparent local illumination factor based on DEM slope and aspect and to sun vector, -1 to 1) 10) UTC time (decimal hours for mid-line pixels) File type: BINARY 64-bit double-precision, floating point. Format: Band interleaved by pixel -------------------------------------------------------------------------------- *ort.hdr ORTHOCORRECTED OBSERVATION PARAMETER FILE (OBS ORT) Contents: Format of each AVIRIS *obs_ort file. This file contains the number of lines, samples, channel, etc. File type: ASCII ---------------------------------------------------------------------------- *ort_img CALIBRATED AVIRIS RADIANCE (IMAGE) DATA Contents: AVIRIS calibrated radiance multipled by the gain and stored as 16-bit integers. File type: BINARY 16-bit signed integer IEEE. Units: gain times (microwatts per centimeter_squared per nanometer per steradian). Format: Band interleaved by pixel (channel, sample, line) with dimensions (224, ns,nl). ------------------------------------------------------------------------------- *ort_img.hdr HEADER FILE FOR CALIBRATED AVIRIS RADIANCE (IMAGE) DATA Contents: Format of each AVIRIS calibrated radiance flight run. This file contains the number of lines, samples, channel, integer format, etc. File type: ASCII ---------------------------------------------------------------------------- Contents of Files located in L2 directory ---------------------------------------------------------------------------- *corr_vn ATMOSPHERICALLY CORRECTED REFLECTANCE (IMAGE) DATA Contents: AVIRIS apparent surface reflectance. File type: BINARY 16-bit signed integer IEEE. Units: unitless quantities from 0 to 1, scaled by a factor of 10000. Format: Band interleaved by pixel (BIP) ----------------------------------------------------------------------------- *corr_vn.hdr HEADER FILE FOR ATMOSPHERICALLY CORRECTED REFLECTANCE (IMAGE) DATA Contents: Format of each AVIRIS reflectance flight run. This file contains the number of lines, samples, channel, integer format, etc. File type: ASCII ---------------------------------------------------------------------------- *h2o_vn WATER ABSORPTION PATH (IMAGE) DATA Contents: Retrieved column water vapor and optical absorption paths for liquid h2o and ice. File type: BINARY 16-bit signed integer IEEE. Units: Band 1 - Column water vapor (cm) Band 2 - Liquid Absorption path (cm) Band 3 - Ice absorption path (cm) Format: Band interleaved by line (BIL) ------------------------------------------------------------------------------ *h2o_vn.hdr HEADER FILE FOR WATER ABSORPTION PATH (IMAGE) DATA Contents: Format of each *h2o_vn file. This file contains the number of lines, samples, channel, integer format, etc. File type: ASCII ------------------------------------------------------------------------------ Contents of Files located in Methane directory ------------------------------------------------------------------------------ *cmfv RETRIEVED METHANE MIXING RATIO LENGTHS (IMAGE) DATA Contents: Retrieved methane mixing ratio lengths in ppm m units estimated from a matched filter detection of the 2300nm absorption feature. File type: BINARY 32-bit signed integer IEEE. Units: Band 1 - CH4 estimated mixing ratio length (ppm m) Band 2 - Mean radiance (uW/sr/cm2/sr) of all channels Format: Band interleaved by line (BIL) ------------------------------------------------------------------------------- *cmfv.hdr HEADER FILE FOR RETRIEVED METHANE MIXING RATIO LENGTHS (IMAGE) DATA Contents: Format of each *cmfv file. This file contains the number of lines, samples, channel, integer format, etc. File type: ASCII ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- ========================================================================= KNOWN ARTIFACTS 1) There is a slew effect in the AVIRIS detector array readout. Slew expresses itself as a slight shift in the IFOV when moving from regions of very different brightnesses. 2) In 2002, the bad detector at channel 77 has been interpolated. =========================================================================