Potential of land degradation index for soil salinity mapping in irrigated agricultural land in a semi-arid region using Landsat-OLI and Sentinel-MSI data.

Irrigated agricultural lands in arid and semi-arid regions are prone to soil degradation. Remote sensing technology has proven useful for mapping and monitoring the extent of this issue. To accurately discern soil salinity, it is essential to choose appropriate spectral wavelengths.

Improvement of diffuse solar irradiance measurements with noncosine instruments.

As a result of sky radiance anisotropy, significant errors spoil diffuse solar irradiance data obtained by means of noncosine-true instruments, which happens in spite of knowledge of the relative cosine response. To reduce these errors we recommend a method that involves an additional measurement of diffuse irradiance from a horizon band. The efficiency of the so-called double-measurement method is found to be optimum for a 25° horizon band elevation.