A practical microwave correlation radiometer was built and tested. Feedback was used to ensure stability and make it unnecessary to match receiver channels. The rms temperature deviation was derived and found to be square root of 2 times that of a total power radiometer. Two separate systems to provide an ac multiplier output were built and evaluated. In one, the receiver channels were tuned to a slightly different frequency while in the other, phase reversal in one channel at an ac rate provided the modulation. The latter method proved easier to instrument. (Author).
A practical microwave correlation radiometer was built and tested. Feedback was used to ensure stability and make it unnecessary to match receiver channels. The rms temperature deviation was derived and found to be square root of 2 times that of a total power radiometer. Two separate systems to provide an ac multiplier output were built and evaluated. In one, the receiver channels were tuned to a slightly different frequency while in the other, phase reversal in one channel at an ac rate provided the modulation. The latter method proved easier to instrument. (Author)
A practical microwave correlation radiometer was built and tested. Feedback was used to ensure stability and make it unnecessary to match receiver channels. The rms temperature deviation was derived and found to be square root of 2 times that of a total power radiometer. Two separate systems to provide an ac multiplier output were built and evaluated. In one, the receiver channels were tuned to a slightly different frequency while in the other, phase reversal in one channel at an ac rate provided the modulation. The latter method proved easier to instrument. (Author).
Thoroughly revising and updating an Artech House classic from 1989, this authoritative resource offers you a comprehensive and current understanding of radiometer systems and shows you how to design a system based on given specifications, taking into account both technical aspects and geophysical realities. The second edition contains a wealth of new material, including coverage of two of today's hottest microwave radiometry topics - polarimetric measurements and aperture synthesis. The book provides you with a complete explanation of radiometer sensitivity, and describes the concept of absolute accuracy and it's associated problems. The four major radiometer principles - total power, Dicke, noise-injection, and correlation - are presented in detail and their sensitivities are derived from the basic sensitivity formula provided in the book. Additionally, you find detailed review of the DTU noise-injection radiometer system.
This volume contains a collection of refereed papers which were presented at the Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 14--17 February 1994, Rome, Italy. The last decade has marked a period of steady advancement and new developments in the observation of the terrestrial environment by passive microwave sensors. Both ground-based and satellite-borne systems have improved their accuracy, stability and spatial resolution and are providing a wealth of quantitative data, which are increasingly being employed in application-oriented projects. The contributions in this volume cover different fields of applications of microwave radiometry, the various observation and retrieval techniques and the recent technological developments. The articles are divided into four sections: measurement of atmospheric water vapor and cloud liquid, measurement of rain, observation of the surface, and new radiometric systems.
This book contains a selection of refereed papers presented at the 6 Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment held in Florence, Italy on March 15-18, 1999. Over the last two decades, passive microwave remote sensing has made considerable progress, and has achieved significant results in the study of the Earth's surface and atmosphere. Many years of observations with ground-based and satellite-borne sensors have made an important contribution to improving our knowledge of many geophysical processes of the Earth's environment and of global changes. The evolution in microwave radiometers aboard satellites has increased steadily over recent years. At the same time, many investigations have been carried out both to improve the algorithms for the retrieval of geophysical parameters and to develop new technologies. The book is divided into four main sections: three of these are devoted to the observation of the Earth's surface and atmosphere, and the fourth, to future missions and new technologies. The first section deals with the study of sea and land surfaces, and reports recent advances in remote sensing of ocean wind, sea ice, soil moisture and vegetation biomass, including electromagnetic modelling and the assimilation of radiometric data in models of land surface processes. The following two sections are devoted to the measurement of atmospheric quantities which are of fundamental importance in climatology and meteorology, and, since they influence radio-wave propagation, they also impact on several other fields, including geodesy, navigational satellite and radioastronomy. The last section presents an overview of new technologies and plans for future missions.
This book contains papers by well renowned scientists from all over world --- including Eastern Europe --- which were presented during a specialist meeting on microwave radiometry and its applications to remote sensing of the atmosphere and the surface of the earth held in Florence, Italy, in March 1988. The book is divided into five sections, some of which contain review papers which summarize the most recent advances in the field. The sections are: -- Microwave radiometry of the earth's surface -- Dielectric properties of natural materials -- Microwave radiometry of the atmosphere -- Synergism of passive and active microwave remote sensors -- Technology of passive microwave systems
