NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Using endmembers in AVIRIS images to estimate changes in vegetative biomassField techniques for estimating vegetative biomass are labor intensive, and rarely are used to monitor changes in biomass over time. Remote-sensing offers an attractive alternative to field measurements; however, because there is no simple correspondence between encoded radiance in multispectral images and biomass, it is not possible to measure vegetative biomass directly from AVIRIS images. Ways to estimate vegetative biomass by identifying community types and then applying biomass scalars derived from field measurements are investigated. Field measurements of community-scale vegetative biomass can be made, at least for local areas, but it is not always possible to identify vegetation communities unambiguously using remote measurements and conventional image-processing techniques. Furthermore, even when communities are well characterized in a single image, it typically is difficult to assess the extent and nature of changes in a time series of images, owing to uncertainties introduced by variations in illumination geometry, atmospheric attenuation, and instrumental responses. Our objective is to develop an improved method based on spectral mixture analysis to characterize and identify vegetative communities, that can be applied to multi-temporal AVIRIS and other types of images. In previous studies, multi-temporal data sets (AVIRIS and TM) of Owens Valley, CA were analyzed and vegetation communities were defined in terms of fractions of reference (laboratory and field) endmember spectra. An advantage of converting an image to fractions of reference endmembers is that, although fractions in a given pixel may vary from image to image in a time series, the endmembers themselves typically are constant, thus providing a consistent frame of reference.
Document ID
19940012216
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Smith, Milton O. (Washington Univ. Seattle, WA, United States)
Adams, John B. (Washington Univ. Seattle, WA, United States)
Ustin, Susan L. (California Univ. Davis., United States)
Roberts, Dar A. (Washington Univ. Seattle, WA, United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1992
Publication Information
Publication: JPL, Summaries of the Third Annual JPL Airborne Geoscience Workshop. Volume 1: AVIRIS Workshop
Subject Category
Earth Resources And Remote Sensing
Accession Number
94N16689
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

IDRelationTitle19940011700Collected WorksTwenty-Fourth Lunar and Planetary Science Conference. Part 2: G-M
No Preview Available