CLPX-Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data

Summary

This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). The AVIRIS has a spectral range of 400-2500 nm, a spectral resolution of 10 nm, instantaneous field of view of 1 mrad, and a scan angle of 15 degrees. Sampling is scene based (~ 815 samples, 512 lines).

The spectral resolution of AVIRIS provides hundreds of spectral bands versus the seven multispectral bands flown on traditional Landsat imaging missions. Through this large number of spectral bands, complex land ecosystems can be imaged and accurately classified.

This data set is part of the NASA Cold Land Processes Field Experiment (CLPX). The NASA CLPX is a multi-sensor, multi-scale experiment that focuses on extending a local-scale understanding of water fluxes, storage, and transformations to regional and global scales. Within a framework of nested study areas in the central Rocky Mountains of the western United States, ranging from 1-ha to 160,000 km2, intensive ground, airborne, and spaceborne observations are collected. Data collection focuses on two seasons: mid-winter, when conditions are generally frozen and dry, and early spring, a transitional period when both frozen and thawed, dry and wet conditions are widespread.

Data are available via FTP.

CAUTIONARY NOTE: These data have not been reviewed for quality. Known issues exist in the processing of these data. Until this disclaimer has been removed, users should send questions and comments about this data set to NSIDC User Services. NSIDC will forward these inquiries to the Principal Investigator for resolution.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation. For more information, see our Use and Copyright Web page.

Painter, T. 2006. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Overview Table

Category Description
Data format Apparent surface reflectance: binary, short integer
Fractional snow-covered area: binary, floating point (data range N [0.0,1.0])
Subpixel snow grain radius: binary, floating point (data range N [0, 1100 micrometers])
Spatial coverage and resolution Southernmost Latitude: 39.70 N
Northernmost Latitude: 41.00 N
Westernmost Longitude: 107.00 W
Easternmost Longitude: 105.50 W

Coverage is not continuous.

Spatial resolution is approximately 1.5 m.
Temporal coverage and resolution 4-8 April 2002; 19-20 Februrary 2003; 25 March-1 April 2003
File naming convention File names include location names.
Reflectance files include ".rfl" in the file name.
Radiance files include ".img" in the file name.
Grain size files include ".grnsz" in the file name.
Snow cover files include ".snow" in the file name.
File size File sizes range from 2 B to 242 MB. Total distribution volume: 1.1 GB
Parameter(s) Apparent surface reflectance, subpixel snow-covered area, and grain size
Procedures for obtaining data Data are available via FTP.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigator

Thomas H. Painter
CIRES/National Snow and Ice Data Center
University of Colorado
Boulder, Colorado USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Detailed Data Description

CAUTIONARY NOTE: These data have not been reviewed for quality. Known issues exist in the processing of these data. Until this disclaimer has been removed, users should send questions and comments about this data set to nsidc@nsidc.org. NSIDC will forward these inquiries to the PI for resolution.

AVIRIS data have the following characteristics:

Format

Apparent surface reflectance: binary, short integer
Subpixel snow-covered area: binary, floating point (data range N [0.0,1.0])
Subpixel snow grain radius: binary, floating point (data range N [0, 1100 micrometers])

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/CLP/data/airborne/nsidc0154_aviris/ directory. Within this directory, there are three folders and a ReadMe file. One folder contains data for the Intensive Observation Period 4 (IOP-4), one folder contains data for reflectances, and one folder contains data for radiances. Within the IOP folder, data files are organized by study area location.

File Naming Convention

The following codes are used in filenames:

File names include location names.
Reflectance files include ".rfl" in the file name.
Radiance files include ".img" in the file name.
Grain size files include ".grnsz" in the file name.
Snow cover files include ".snow" in the file name.
Vegitation cover files include ".veg" in the file name.

Each file is named by its location and then a date of the form yymmdd.

File Size

File sizes range from 2 B to 242 MB.

Spatial Coverage

Southernmost Latitude: 39.70 N
Northernmost Latitude: 41.00 N
Westernmost Longitude: 107.00 W
Easternmost Longitude: 105.50 W

Coverage is not continuous.

Spatial Resolution

Spatial resolution is approximately 1.5 m.

Temporal Coverage

AVIRIS measurements were made on 4-8 April 2002; 19-20 Februrary 2003; and 25 March-1 April 2003.

Parameters or Variables

Apparent surface reflectance

Subpixel snow-covered area

Grain size

Parameter Description

AVIRIS measures calibrated radiance. The data include apparent surface reflectance, subpixel snow-covered area, and grain size.

For a complete description of parameters and measurements, please refer to the Measurements section of the CLPX Plan.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

Total data volume is 1.1 GB.

Related Data Collections

4. Data Acquisition and Processing

For complete information about data acquisition and processing regarding CLPX, please see the Cold Land Processes Field Experiment (CLPX) Plan Web Site.

For complete information about data acquisition and processing, please see JPL's AVIRIS Data Facility Web site.

5. References and Related Publications

Please see the References section of the CLPX Plan.

6. Document Information

List of Acronyms

The following acronyms and abreviations are used in this document:

Acronym Description
AVIRIS Airborne Visible/Infrared Imaging Spectrometer
CLPX Cold Land Processes Field Experiment
FTP File Transfer Protocol
IOP Intensive Study Period
NASA National Aeronautics and Space Administration
NSIDC National Snow and Ice Data Center
URL Uniform Resource Locator

Document Creation Date

12 April 2006

Document Revision Date

20 August 2007

Document URL

http://nsidc.org/data/docs/daac/nsidc0154_clpx_aviris/index.html