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

Canada contains 10% of the world´s forests, covering an area of 418 million ha. Remote sensing can provide rapid coverage of these forests. Forest information needs are moving from broad forest typing to mapping of major forest species. Hyperspectral sensing can be used to create products for forest inventory, forest health, biomass, and aboveground carbon. The challenge is to develop a process to extract from hyperspectral data the relevant forest information in a timely and reproducible manner with a high degree of confidence in the quality of the resultant products. To answer this challenge, experiments have been conducted on two test sites: the Greater Victoria Watershed District (GVWD) on Vancouver Island, BC, and the Hoquiam test site in Washington State. Three types of data were collected to perform the analysis. First, Hyperion and AVIRIS hyperspectral images were collected for both test sites. Secondly, ground truth reflectance data were acquired from locations within the GVWD test sites simultaneously with these image collections. Finally, foliar samples were taken and chemically analyzed from 30 Douglas fir plots in the GVWD test site and five plots in the Hoquiam test site to provide a sample set of known values to compare against the spectral imagery. This paper reports on the results for chlorophyll and nitrogen mapping for these sites. Difficulties associated with chemistry signature extension are discussed. For nitrogen, an r2 of 0.915 was obtained between ground measured nitrogen and nitrogen predicted from AVIRIS data.