Assessing the accuracy indicators of the ground-based spectral estimation of soil moisture

Abstract

Contact point field measurements of soil moisture are characterized by low productivity.  High efficiency of determining and monitoring soil moisture can be achieved remote sensing. The known microwave methods for remote determination of soil moisture have low spatial resolution, are expensive and hence unsuitable for the use in agriculture. For estimating soil moisture content, the article proposes the ground-based on-board complex, which includes an on-board passive meter of the optical signal reflected from the soil and a ground contact meter. Operation of the latter can be performed either by an automatic measuring network or by an operator conducting contact measurements. The authors formulated and solved the problem related to assessing the accuracy of validation of the on-board measurement of soil moisture content. As an on-board meter, a passive radiation spectroradiometer of the soil illuminated by the Sun is used, and as a ground meter, a contact meter is used for estimating soil moisture at different spatial increments. The accuracy indicators of ground measurements and their relationship with the estimated values were analyzed. Comparison of the results obtained by the ground and on-board measurements allowed to determine the relationship between the moisture content measured from the board and the error of ground measurements as a validation error.