https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1037&context=nasapub

First operational BRDF, albedo nadir reflectance products from MODIS

https://sites.bu.edu/cliveg/files/2013/09/myneni.modis_1.pdf

Global products of vegetation leaf area and fraction absorbed PAR from year one of MODIS data

SUMMARY A one-dimensional model is adopted to describe the energy partition of sparse crops. Theoretical development of this model yields a combination equation which describes evaporation in terms of controlling resistances associated with the plants, and with the soil or water in which they are growing. The equation provides a simple but physically plausible description of the transition between bare substrate and a closed canopy. Although the aerodynamic transfer resistances for incomplete canopies have, as yet, no experimental justification, typical values, appropriate to a specimen agricultural crop and soil, are shown to have limited sensitivity in the model. Processes which require further study if the equation is to be used to calculate evaporation throughout a crop season are also discussed. Previous steps in the development of a physically based model of the vegetationatmosphere interaction (e.g. Shuttleworth 1976, 1978) explicitly treat the vegetation as a closed, stable canopy of uniform structure. They emphasize the interaction of the vegetation, with fluxes arising at the soil surface introduced as an unspecified, and implicitly small, input to the model (Shuttleworth 1979). In this paper this theoretical work is reinterpreted and developed into the situation of sparse crops, where the use of a one-dimensional model has less obvious justification. In describing such crops the soil and plant components must carry equal status, since they can be of similar size and their relative importance can change significantly with crop cover. The philosophy of this paper is to make minimum concession to the more obvious three-dimensional structure of sparse and row crops. Accordingly a one-dimensional model of the interaction is adopted to derive a combination equation, which can provide a physically plausible transition between the bare substrate and closed canopy limits. The equation is expressed in terms of conceptual resistances now familiar to the micrometeorologist and plant physiologist: canopy resistance and boundary layer resistance etc; it also requires the less familiar concept of a surface resistance for bare soil (Monteith 1981). In the later sections of the paper typical values of these resistances are used to illustrate how energy partition varies between crops of the same height, but with different leaf areas.

Evaporation from sparse crops‐an energy combination theory

Source approach for estimating soil and vegetation energy fluxes in observations of directional radiometric surface temperature

The first Moderate Resolution Imaging Spectroradiometer (MODIS) instrument is planned for launch by NASA in 1998. This instrument will provide a new and improved capability for terrestrial satellite remote sensing aimed at meeting the needs of global change research. The MODIS standard products will provide new and improved tools for moderate resolution land surface monitoring. These higher order data products have been designed to remove the burden of certain common types of data processing from the user community and meet the more general needs of global-to-regional monitoring, modeling, and assessment. The near-daily coverage of moderate resolution data from MODIS, coupled with the planned increase in high-resolution sampling from Landsat 7, will provide a powerful combination of observations. The full potential of MODIS will be realized once a stable and well-calibrated time-series of multispectral data has been established. In this paper the proposed MODIS standard products for land applications are described along with the current plans for data quality assessment and product validation.

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The Moderate Resolution Imaging Spectroradiometer (MODIS): land remote sensing for global change research

one: Plant stand architecture.- 1.1 Role of Phytometric Investigations in The Studies of Plant Stand Architecture and Radiation Regime.- 1.2 Principal Phytometric Characteristics of Stands.- 1.2.1 Phytometric characteristics of leaf and other plant organs.- 1.2.2 Phytometric characteristics of an individual plant.- 1.2.3 Phytometric characteristics of a pure stand.- 1.2.4 Plant stand as a horizontal layer.- 1.3 Phytometrical Methods.- 1.3.1 Determination of leaf area.- 1.3.2 The measurement of leaf orientation.- 1.3.3 Inclined point quadrats method.- 1.3.4 Stratifying clip method.- 1.3.5 The methods of statistical measurements.- 1.3.6 Numerical methods for determination of foliage area vertical distribution.- 1.3.7 A rational method for determining phytometric characteristics of stand architecture and productivity.- 1.4 Statistical Characteristics of A Stand.- 1.4.1 Parameters of statistical characteristics.- 1.4.2 Correlation between statistical characteristics.- 1.5 Spatial Distribution of Phytoelements in Stands.- 1.5.1 General.- 1.5.2 Space-time variability of transition functions.- 1.5.3 Vertical distribution of phytomass and phytoarea.- 1.5.4 Horizontal distribution of phytomass and phytoarea.- 1.6 Foliage Area Orientation in Stands.- 1.6.1 General.- 1.6.2 Distribution functions of leaf inclination and azimuth orientation.- 1.6.3 G-function of leaf orientation.- 1.7 Plant Stand Architecture, Photosynthesis and Productivity.- two: Radiation regime in plant stand.- II.1 Radiation Field in a Plant Stand and The Problem of Its Mathematical Modelling.- II.1.1 General.- II. 1.2 Basic characteristics of the radiation field.- II. 1.3 Optical characteristics of phytoelements.- II. 1.4 Optical characteristics of plate medium.- II. 1.5 The radiation transfer equation for an optically anisotropic plate medium.- IL 1.6 Plant stand as a plate medium.- IL 1.7 The radiation transfer equation for a plant stand.- II. 1.8 Leaf and plant stand absorption functions.- II. 1.9 Statistical character of the radiation field in plant stands.- 11.2 Incident Radiation.- II.2.1 General.- IL2.2 Incoming direct solar radiation.- 11.2.3 Incoming diffuse sky radiation.- 11.2.4 Incoming total solar radiation.- 11.2.5 Incoming long-wave radiation of the atmosphere.- 11.2.6 Photosynthetically active radiation.- 11.3 Optical Properties of Phytoelements.- 11.3.1 General.- 11.3.2 Optical models of the leaf.- 11.3.3 Scattering phase function of the leaf.- 11.3.4 Spectral optical properties of phytoelements.- 11.3.5 Integral coefficients of leaf reflection, transmission and absorption for short-wave radiation and PAR.- 11.3.6 Optical properties of phytoelements in the long-wave spectral region.- 11.4 Penetration of Direct Solar Radiation into a Plant Stand.- 11.4.1 General.- 11.4.2 Statistical character of penetration of direct radiation in a plant stand. Penumbras.- 11.4.3 Theoretical expressions for direct solar radiation penetration.- 11.4.4 Penetration theory for direct solar radiation in horizontally inhomogeneous plant stands.- 11.4.5 Calculated penetration of direct solar radiation and its dependence on various factors.- 11.4.6 Methods of experimental investigation.- 11.4.7 Experimental data on penetration.- 11.5 Penetration of Diffuse Sky Radiation Into Plant Stand.- 11.5.1 General.- 11.5.2 Penetration formulae.- 11.5.3 Calculation of intensities and zonal radiation.- 11.5.4 Calculation of downward fluxes.- 11.5.5 Method of hemispherical photographs.- 11.5.6 Statistical character of the penetration of diffuse sky radiation.- 11.6 Scattering of Radiation Inside Plant Stands.- 11.6.1 General.- 11.6.2 Scattering and absorption coefficients for an elementary volume in a plant stand. Scattering phase function.- 11.6.3 Solution of radiation transfer equation for horizontal leaves.- 11.6.4 The Schwarzschild approximation for modified radiative transfer equation.- 11.6.5 Approximation for single scattering.- 11.6.6 Leaf scattering coefficient ?L and the complementary radiation field.- 11.6.7 Calculation of the complementary PAR field.- 11.6.8 Calculation of the complementary NIR field.- 11.7 Total Radiation Field in Plant Stands.- 11.7.1 General.- 11.7.2 Intensities of total radiation field.- 11.7.3 Total vertical fluxes.- 11.7.4 Angular distribution of total radiation flux.- 11.7.5 Leaf absorption in total radiation field.- 11.7.6 Radiation in a plant stand with horizontal leaves.- 11.7.7 Errors of the approximate methods of calculation.- 11.7.8 New theories.- 11.7.9 Monte Carlo simulation models.- 11.8 Semiempirical Formulae for Total Radiation Fluxes.- 11.8.1 General.- 11.8.2 Exponential and binomial semiempirical formulae.- 11.8.3 New semiempirical formulae.- 11.9 Albedo of Plant Stand.- 11.9.1 General.- 11.9.2 Formulae for the albedo and brightness coefficient.- 11.9.3 Albedo and its dependence on various factors.- 11.9.4 Comparison of calculated and experimental data.- 11.10 Calculation of Long-Wave Radiation in A Stand.- 11.11 Net Radtation in Plant Stands.- Conclusion.- Supplement. Description of Field Experiments.- References.- Author Index.

Juhan Ross

Papers

The radiation regime and architecture of plant stands