Receiver Bandwidth

2020 ◽  
Author(s):  
Keyword(s):  
2012 ◽  
Vol 5 (6) ◽  
pp. 8085-8130
Author(s):  
V. Meunier ◽  
U. Löhnert ◽  
P. Kollias ◽  
S. Crewell

Abstract. More so than the traditional fixed radiometers, the scanning radiometer requires a careful design to ensure high quality measurements. Here the impact of the radiometer characteristics (e.g. antenna beam width, receiver bandwidth) and atmospheric propagation (e.g. curvature of the earth and refractivity) on the scanning radiometer measurements are presented. A forward radiative transfer model that includes all these effects to represent the instrument measurements is used to estimate the biases as differences between the measurement with and without these characteristics for three commonly used frequency bands: K, V and W-band. The receiver channel bandwidth errors are not so important in K-band and W-band. Thus, the use of a wider bandwidth to improve detection at low signal-to-noise conditions is acceptable. The impact of the antenna beam width is higher than the receiver bandwidth, but, for V-band where they are of similar importance. Using simple regression algorithms, the effects of the bandwidth and beam width biases in liquid water path, integrated water vapor, and temperature are also examined. The largest errors in liquid water path and integrated water vapor are associated with the beam width errors.


2018 ◽  
Vol 7 (1) ◽  
pp. 66-70
Author(s):  
Abhinav Singh Andotra ◽  
Sandeep Sharma

Segmentation plays an important role in separating data from medicinal images and also helps in clinical findings. Segmentation is the way toward apportioning the image into different regions. MRI is utilized to extract images of delicate tissues of human body. It is utilized in analyzing the human organs without the requirement of surgery. For the most part MRI images contain a lot of noise caused by operator performance, equipment and the environment, which prompts genuine errors. MRI is a productive way in giving data in regards to the area of tumors and even the volume. The noise present in the MRI image can be evacuated by utilizing different de-noising procedures whichever is most appropriate method depending on the type of image obtained and afterward can be handled by any of the segmentation techniques. The noise in MRI images might be because of field strength, RF pulses, RF coil, voxel volume, or receiver bandwidth. In our proposed paper a review of different noise handling and filtering mechanism is conducted in order to enhance the quality of image. In this paper we modify the adaptive median filter by applying redundancy handling mechanism and enhance the contrast of image by applying histogram equivalence method.


2018 ◽  
Vol 60 (10) ◽  
pp. 1089-1092 ◽  
Author(s):  
Max Scheffler ◽  
Enrique Maturana ◽  
Rares Salomir ◽  
Sven Haller ◽  
Enikö Kövari

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