Two solutions for UHF RFID tags for soil moisture sensing were designed and are described in this paper. In the first, two conventional tags (standard transponders) are employed: one, placed close to the soil surface, is the sensor tag, while the other, separated from the soil, is the reference for system calibration. By transmission power ramps, the tag's turn-on power levels are measured and ...

The objective of this study was to use the process-oriented precision farming crop growth model APOLLO to identify problem grids for crop production within a field. The model was calibrated for a wheat and a corn field. During the calibration process soil parameters were adjusted iteratively for each grid within the fields, using a simulated annealing algorithm. This procedure gave good yield e...

Land-sea contamination observed in SMOS (Soil Moisture and Ocean Salinity) brightness temperature images is found to have two main contributions: the floor error inherent of image reconstruction and a multiplicative error either in the antenna temperature or in the visibility samples measured by the correlator. The origin of this last one is traced down to SMOS calibration parameters to yield a...

The authors made calibration of an end-window Geiger Müller (GM) survey meter in terms of the beta dose rate and applied it to measurements of the beta dose rate in the environments contaminated by the Fukushima Daiichi nuclear accident. The range of validity of the calibration factors to be applied to the GM probe was verified (1) by the measurement of contaminated soil samples removed from th...

The Soil and Water Assessment Tool version 2000 (SWAT2000) watershed model was utilized to simulate the transport of flow, sediments and phosphorus to the Cannonsville Reservoir in Upstate, New York. The available datasets for model development , particularly the phosphorus input and water quality calibration data, in this case study are unique because of the large amount of watershed specific,...

This paper describes an automated calibration procedure applied to the GIS-based distributed WetSpa (Water and Energy Transfer between Soil, Plant and Atmosphere) model by incorporating a modelindependent parameter estimator PEST (Parameter ESTimation). This calibration approach is applied to estimate the most sensitive parameters of the model with observed flow hydrographs as the calibration t...

The Soil Water Assessment Tool (SWAT) was implemented in the 281,000 ha St. Joseph River Watershed (SJRW) to investigate the influence of multiple scales on stream flow model calibration parameters (Fig.1). The relationship between model calibration parameters and associated hydrological response units (HRU) between different scales is not well understood. In this investigation, two scales were...

[1] Accounting for small‐scale spatial heterogeneity of soil moisture ( ) is required to enhance the predictive skill of land surface models. In this paper, we present the results of the development, calibration, and performance evaluation of a downscaling model based on multifractal theory using aircraft‐based (800 m) estimates collected during the southern Great Plains experiment in 1997 (SGP...

Soil CO2 efflux is a major component of net ecosystem productivity (NEP) of forest systems. Combining data from multiple researchers for larger-scale modeling and assessment will only be valid if their methodologies provide directly comparable results. We conducted a series of laboratory and field tests to assess the presence and magnitude of soil CO2 efflux measurement system · environment int...