Wojciech Marczewski

Comparison of surface soil moisture from SMOS satellite and ground measurements

Abstract Soil moisture datasets at various scales are needed for sustainable land use and water management. The aim of this study was to compare soil moisture ocean salinity satellite and in situ soil moisture data for the Podlasie and Polesie regions in Eastern Poland. Both regions have similar climatic and topographic conditions but are different in land use, vegetation, and soil cover. The test sites were located on agricultural fields on sandy soils and natural vegetation on marshy soils that prevail in the Podlasie and Polesie regions, respectively. The soil moisture ocean salinity soil moisture data were obtained from radiometric measurements (1.4 GHz) and the ground soil moisture from sensors at a depth of 5 cm during the years 2010-2011. In general, temporal patterns of soil moisture from both satellite and ground measurements followed the rainfall trend. The regression coefficients, Bland-Altman analysis, concordance correlation coefficient, and total deviation index showed that the agreement between ground and soil moisture ocean salinity derived soil moisture data is better for the Podlasie than the Polesie region. The lower agreement in Polesie was attributed mostly to the presence of the widespread natural vegetation on the wetter marsh soil along with minor contribution of agriculturally used drier coarse-textured soils.

The Overlapped Microstrip for MICs and MMICs

The overlapped microstrip-like lines and their applications feasible by means of MIC and MMIC technology have been presented. Several 3dB coupler designs and a microstrip representation of the Marchand balun are suggested as good alternatives to the well known devices. The coupler results are used to prove the balun feasibility. The brief discussion on the quasi-TEM analysis results is stressing the significance of asymmetric structures. The experimental results are limited to the MIC technology using alumina substrate.

Ring of Four Overlapped Microstrip Hybrid Couplers

The ring of couplers known from Butler matrix, correlators and direction finding systems has been discussed in the paper. The ring of four hybrid couplers is a regular pattern of a fundamental eight-port forming a set of four output responses. The responses can be excited in two orthogonal modes. The eight port with ring of five hybrid couplers has been included as an extension of the basic ring of four couplers. The pentagonal ring enables four way distribution in three modes. All available modes have been discussed on the base of perfect scattering matrix. Both the rings were embodied using broadside coupled Overlapped Microstrip lines with PTFE substrates and were measured in frequency ranges 2-16GHz and 10-20GHz. The presented results prove existence of recognized modes in real imperfect embodiments within approximate bandwidth of an octave. The rings are devoted for widely meant analog signal processing.