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S
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
1 bi = |ReZ i |-1/2 (Vi - Z i Ii ) 2 where Z i is the reference impedance and the asterisk denotes the complex conjugate. It is also known as S-matrix. scattering parameters parameters that characterize a microwave network with an arbitrary number of ports by relating the voltage waves incident on the ports to those reflected from the ports. Also known as S-parameters. The scattering parameters are often represented in terms of a scattering matrix. See also scattering matrix. scattering resonance sharp increase (or decay) of the scattered energy as a function of either frequency or observation direction, as for the glory or the rainbow. scatterometer a device to measure the angular distribution of scattered intensity. Its main component contains a photodetector mounted over a goniometer.
Active Microwaves
Published in Iain H. Woodhouse, Introduction to Microwave Remote Sensing, 2006
Scatterometers are important instruments because they can provide well-calibrated cross-section measurements over a variety of targets that can be used to help provide insight into the way in which microwaves interact with natural objects, or as operational data for monitoring aspects of the environment. Chapter 5 described in some detail the backscattering properties of natural targets. Good quality scatterometer measurements should therefore help to provide information on properties such as sea surface roughness, soil moisture or vegetation cover. A great deal of important work has been done with ground-based scatterometers, both inside the lab and in the field to verify scattering models and generate databases of scattering properties. Scatterometers are also flown on aircraft or helicopters, and a scatterometer was flown on the NASA Skylab mission in the 1970s and made measurements across the globe.
Remote Sensing Sensors and Platforms
Published in Ni-Bin Chang, Kaixu Bai, Multisensor Data Fusion and Machine Learning for Environmental Remote Sensing, 2018
Microwave instruments that are designed for finer environmental monitoring and earth observation may include, but are not limited to: Scatterometer: A high-frequency microwave radar that is designed to measure backscattered radiation over ocean surfaces to derive maps of surface wind speed and direction.Sounder: An active sensor that specifically measures vertical distribution of atmospheric characteristics such as humidity, temperature, and cloud composition, as well as precipitation.
Information fusion approach for downscaling coarse resolution scatterometer data
Published in International Journal of Image and Data Fusion, 2023
Ajay Kumar Maurya, Anjana Naga Jyothi Kukunuri, Dharmendra Singh
Scatterometer provides the backscattering signal from the land surface in the form of σ° products. σ° is used for various applications such as soil moisture estimation (Bhimala and Goswami 2015, Lindell and Long 2016, Brocca et al. 2017, Murugan et al. 2019, Maurya et al. 2021), crop classification, crop phenology, crop parameter estimation (Chaube et al. 2019, Singh et al. 2020), and snow cover classification (Yackel et al. 2019). Unfortunately, due to its low spatial resolution, its applications are limited in regional studies. This limitation can be overcome by applying appropriate downscaling algorithms. The coarse-resolution backscattering signal obtained from the scatterometer is the contribution of various land cover classes present in a given pixel. Therefore, efficient downscaling requires information about various factors which are the major contributors.