Calibration of forest chemistry for hyperspectral analysis

Abstract

Abstract-A primary advantage of hyperspectral sensors is the ability to provide measurements of canopy chemistry. Canopy chemistry can be used to estimate new and old foliage, detect damage, identify trees under stress, and map chemical distributions in the forests. We have begun a new EO-1 project, Evaluation and Validation of EO-1 for Sustainable Development of forests (EVEOSD). NASA's EO-1 satellite was successfully launched on November 21, 2000. In preparation for airborne and spaceborne data collection and calibration, we collected in September 2000 foliar canopy and ground cover chemistry samples from 54 plots distributed across the Greater Victoria Watershed (GVWD) test site. Treetop samples were collected from helicopters. Differential GPS was used to provide sample positioning to within 1 m. The foliar samples were divided into new and old foliage. Organic and inorganic chemistry analyses were done. Spectral calibration samples were collected over ground targets, over stacks of foliar samples, and over ground vegetation. Landsat-7 and Radarsat data were collected at the same time. The chemistry samples were placed into a database and integrated with GIS files of topography and forest cover. We obtained 1 m aerial orthophotography that allowed us to investigate the spectral components making up the Landsat-7 and EO-1 pixels. This paper describes the experimental design and the ground and canopy chemistry. Examples of unique concentrations, such as high levels of arsenic in foliar samples, are shown spatially. Recommendations are made for experimental design for ground reference collection for hyperspectral calibration.

Forest information products from hyperspectral data — Victoria and Hoquiam test sites

“…Both test sites are representative of temperate coastal rainforest dominated by Douglas-fir and Western Hemlock tree species. A more detailed description of the GVWD study site can be found in [5].…”

“…A summary of the hyperspectral data collected is given in Table I. Extensive field work on 54 plots (10 trees per plot) was conducted at GVWD [5] in 2000. Additional sampling of one tree from each plot was performed in 2001 to confirm the stability of the measured chemistry from year to year.…”

Hyperspectral sensing of forests

“…Both test sites are representative of temperate coastal rainforest dominated by Douglas-fir and Western Hemlock tree species. A more detailed description of the GVWD study site can be found in (1).…”

Hyperspectral remote sensing of conifer chemistry and moisture

“…During the growing seasons of 2000 and 2001, airborne hyperspectral remotely sensed imagery, as well as foliar chemistry samples, were collected from the GVWD by the Pacific Forestry Centre (PFC), Natural Resources Canada (NRCAN), under the Evaluation and Validation of EO-1 for Sustainable Development (EVEOSD) Project [6].…”