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Estimation of Soil Surface Roughness Parameters Under Simulated Rainfall Using Spectral Reflectance in Optical Domain
AbstractThe purpose of the study was to evaluate the possibility of parameterizing the state of soil surface roughness (SSR) based on proximal measurements of spectral reflectance in the VIS‐NIR range, which is important for the needs of monitoring the state of soil surfaces. SSR should be constantly monitored as it provides an insight into a range of hydrological and erosive soil processes and improves the interpretation of remote sensing data. SSR and the spectral reflectance of three texturally different soils were measured under simulated rainfall in laboratory condition. The relationship between the SSR parameters and soil spectra was determined using regression random forest models. Various spectral data processing methods were tested and the best wavelengths for SSR description after rainfall were found. Two roughness indices were used to describe the SSR: Height Standard Deviation (HSD) and T3D (Tortuosity index). Although both shared a significant correlation with SSR, the T3D index demonstrated a more pronounced rainfall effect and a closer correlation with spectral data than HSD. The best determination of T3D was obtained with the raw spectra (RAW) (R2 = 0.71), as well as with spectra transformed with the baseline alignment first derivative (BA1d) method (R2 = 0.71) or the Savitzky‐Golay (SG) method (R2 = 0.69). Different wavelengths were the best SSR predictors depending on the spectral transformation method (VIPs ‐ Variable Importance in Projection). For both roughness indices, the NIR wavelengths (725–820 nm) yielded the highest VIP Score in models based on RAW spectra, while those in the VIS region (450–772 nm) were most important in models based on transformed spectra.
Multidimensional discriminant analysis of species, strains and culture age of closely related entomopathogenic fungi using reflectance spectroscopy
Reflectance spectroscopy and machine learning as a tool for the categorization of twin species based on the example of the Diachrysia genus
Ocena użyteczności metody Bikermana do wyznaczania kątów zwilżania liści
The physico-chemical properties of the spray liquid affect the efficiency and effectiveness of crop protection treatments. A measure of leaf wettability is the wetting angle, the testing of which is neglected in routinely performed spraying. In the search for a method useful for determining leaf wetting angle for crop protection treatments, the method that Bikerman (1941) applied to the surface of the object observed from above was evaluated. The assumptions of the method and the resulting opportunities and constraints in its application are presented in this paper. The influence of leaf, liquid and droplet properties on the wetting angle was discussed. It was concluded that Bikerman’s method is suitable for determining leaf wetting angles over a wide range of physical properties of liquids used in crop protection treatments.