A model for sim~ating the measured radar backscattering coefficient of vegetation-covered soil surfaces is presented in this study. The model consists of two parts: the first is a soft surface model to describe the backscattered radar pulses from a rough soil surface, and the second part takes into account the effect of vegetation cover. The soil surface is characterized by two parameters, the ...

This paper discusses the sensitivity of scatterometric and radiometric sensors to the surface characteristics of canopy-covered soils, and compares their performances in separating crops and in measuring soil moisture and vegetation biomass.

In preparation for new satellite sensors, such as VEGEciated with vegetation, and as an input to ecosystem proTATION on SPOT-4 and the MODerate Resolution Imductivity models (Sellers et al., 1986; Bonan, 1993; Liu aging Spectrometer (MODIS), we investigate the potenet al., 1997). The need for LAI information over large tial of the shortwave infrared (SWIR) signal to improve areas has prompted i...

Photosynthesis provides plants with their main building material, carbohydrates, and with the energy necessary to thrive and prosper in their environment. We expect, therefore, that natural vegetation would evolve optimally to maximize its net carbon profit (NCP), the difference between carbon acquired by photosynthesis and carbon spent on maintenance of the organs involved in its uptake. We mo...

While ecological succession shapes contemporary forest structure and dynamics, other factors like forest structure (dense vs. sparse canopies) and climate may alter structural trajectories. To assess potential sources of variation in structural trajectories, we examined proportional biomass change for a regionally dominant tree species, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), across...

The e€ects of landscape changes on winter and spring snow-related processes, and on regional weather and climate are not thoroughly understood. In this study, a climate version of the Regional Atmospheric Modelling System (ClimRAMS) is used to investigate the e€ects of landscape change on seasonal snow depletion and its corresponding e€ects on atmospheric and hydrologic processes. Two simulatio...

Optical remote sensing provides us with a two dimensional representation of land-surface vegetation and its reflectance properties which can be indirectly related to biophysical parameters (e.g. NDVI, LAI, fAPAR, and vegetation cover fraction). However, in our interpretation of the world around us, we use a three-dimensional perspective. The addition of a vertical dimension allows us to gain in...

The fraction of absorbed photosynthetically active radiation (FPAR) is a key parameter in describing the exchange of fluxes of energy, mass and momentum between the surface and atmosphere. In this study, we present a method to measure FPAR using a digital camera and a reference panel. A digital camera was used to capture color images of low canopy vegetation, which contained a reference panel i...

Ground penetrating radar (GPR) with a suspended 1 GHz horn antenna was deployed for measurement of soil water contents and dwatj wheat canopy reflections over bare and electrically terminating sutjaces. Sutjace reflection (SR) magnitudes and propagation times (PI) were used to independently calculate bulk soil dielectric constant and soil water contents. Measurements over wheat canopy shows tha...

.......................................................................................................................................... 1 Acknowledgements ......................................................................................................................... 2 Introduction .........................................................................................................