ECOLOGICAL RESEARCH NEEDS FROM MULTIANGLE REMOTE-SENSING DATA

Remotely sensed land surface reflectance depends upon changing sun and sensor viewing geometry, and this dependence is governed by the bidir ectional reflectance distribution function (BRDF). Because the reflect ance distribution of vegetation is strongly anisotropic, multi-view an gle (MVA) observations of terrestrial ecosystems contain additional an d unique information beyond that acquired with nadir or single-angle s pectral measurements alone. With the NASA EOS instruments MODIS and MI SR and France's POLDER, new capabilities in MVA remote sensing will be come widely available or ecological, biogeochemical, and land-surface biophysical research. However, a communication gap exists between the remote sensing and ecological communities in terms of the capabilities of the former and the needs of the latter. In this article, we presen t a summary of ecological research needs for remotely sensed data. Bas ed on these needs, we present a review of some of the most promising M VA remote sensing methods for fulfilling these requirements. With this article, we hope to facilitate increased communication between the re mote sensing, ecological, and biogeochemical research communities. (C) Elsevier Science Inc., 1998.