I zy A Review of Reflectance Nomenclature Used in Remote Sensing Carol J. Bruegge and John V. Martonchik zyxw Jet Propulsion Laboratory California Institute of Technology, Pasadena, zyxw CA Alan H. Strahler Department of Geography and Center for Remote Sensing Boston Universiy, Boston, MA Abstract Field and laboratory radiometers have long been used to characterize homogeneous surface targets for their multiangle reflectance properties. Within the last few years space-based multiangle imaging spectroradiometers have been deployed, including the Along-Track Scanning Radiometer-2 (ATSR), the Polarization and Directionality of the Earth’s Reflectances (POLDER) instrument, and the Multiangle Imaging SpectroRadiometer (MTSR). Other scanning instruments, such as the Moderate Resolution Imaging Spectrometer (MODIS) make use of successive passes to make multiangle observations. The synergistic approach of global monitoring from space, combined with localized detailed observations from the field, will allow greater exploitation of these multiangle data. As this science advances, results will likewise require additional preciseness of terminology in order to differentiate between parameters which may be reported in a variety of spectral and field-of-view integrations, as well as inherent versus observed properties. This paper reviews the reflectance terminology that is used by the remote sensing community. 1. Introduction The angular reflectance pattern of clouds, aerosol layers, vegetation canopies, soils, and snow and ice fields are now being measureh by the remote sensing community. Application of these data include studies of the Earth’s radiation balance, climate, and land use change. Of particular interest is the impact of varying cloud, aerosol, and surface cover type on the distribution of radiation within the atmosphere/surface system. Multiangle data is important in this regard since it allows another dimension of information to be exploited in the process of decoupling surface radiative effects from atmospheric effects. The ability to obtain multiangle data on a global basis has only been available within the last decade, starting with the Along-Track Scanning Radiometer (ATSR) launched in 1991 on ERS-1. The most recent instruments include the ATSR-2 [Stricker et al., 19951 on ERS-2, the Polarization and Directionality of the Earth’s Reflectances (POLDER) instrument [Deschamps et al., 19941 on ADEOS (operational from November 1996 to June 1997). and the Multiangle Imaging SpectroRadiometer (MISR) [Diner, et al., 19981 on EOS Terra. The Moderate Resolution Imaging Spectrometer (MODIS) [Barnes, et al., 19981, also on EOS Terra. is a traditional cross-track To be submitted to Journal Geophy. Res. Draft date January 7,2000.