Error budget and expected performance of the VLT unit telescopes

1994 ◽  
Author(s):  
Philippe Dierickx
Keyword(s):  
Error Budget ◽  
Expected Performance

The Gran Telescopio Canarias laser guide star AO system: error budget and expected performance

2018 ◽  
Author(s):  
Iciar Montilla Garcia ◽  
Alastair G. Basden ◽  
Marcos Reyes Garcia-Talavera ◽  
Roberto Simoes ◽  
Jorge Sánchez-Capuchino ◽  
...  
Keyword(s):  
Laser Guide Star ◽  
System Error ◽  
Error Budget ◽  
Expected Performance ◽  
Guide Star ◽  
Laser Guide

The miR-21 potential of serving as a biomarker for liver diseases in clinical practice

2020 ◽  
Vol 48 (5) ◽  
pp. 2295-2305
Author(s):  
Jiawei Zhang ◽  
Dandan Li ◽  
Rui Zhang ◽  
Peng Gao ◽  
Rongxue Peng ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Liver Diseases ◽  
Hepatic Disease ◽  
Noninvasive Detection ◽  
Diagnosis And Prognosis ◽  
Expected Performance ◽  
Potential Biomarker ◽  
Disease Condition ◽  
Complex Regulatory Network

The role of miR-21 in the pathogenesis of various liver diseases, together with the possibility of detecting microRNA in the circulation, makes miR-21 a potential biomarker for noninvasive detection. In this review, we summarize the potential utility of extracellular miR-21 in the clinical management of hepatic disease patients and compared it with the current clinical practice. MiR-21 shows screening and prognostic value for liver cancer. In liver cirrhosis, miR-21 may serve as a biomarker for the differentiating diagnosis and prognosis. MiR-21 is also a potential biomarker for the severity of hepatitis. We elucidate the disease condition under which miR-21 testing can reach the expected performance. Though miR-21 is a key regulator of liver diseases, microRNAs coordinate with each other in the complex regulatory network. As a result, the performance of miR-21 is better when combined with other microRNAs or classical biomarkers under certain clinical circumstances.

scholarly journals An Analytical Method for Dynamic Wave-Related Errors of Interferometric SAR Ocean Altimetry under Multiple Sea States

2021 ◽  
Vol 13 (5) ◽  
pp. 986
Author(s):  
Yao Chen ◽  
Mo Huang ◽  
Yuanyuan Zhang ◽  
Changyuan Wang ◽  
Tao Duan
Keyword(s):  
Electromagnetic Scattering ◽  
Analytical Method ◽  
Wave Spectrum ◽  
High Accuracy ◽  
Sea State ◽  
Error Budget ◽  
Ocean Topography ◽  
Mean Square Errors ◽  
Dynamic Wave ◽  
Wide Swath

The spaceborne interferometric synthetic aperture radar (InSAR) is expected to measure the sea surface height (SSH) with high accuracy over a wide swath. Since centimeter-level accuracy is required to monitor the ocean sub-mesoscale dynamics, the high accuracy implies that the altimetric errors should be totally understood and strictly controlled. However, for the dynamic waves, they move randomly all the time, and this will lead to significant altimetric errors. This study proposes an analytical method for the dynamic wave-related errors of InSAR SSH measurement based on the wave spectrum and electromagnetic scattering model. Additionally, the mechanisms of the dynamic wave-related errors of InSAR altimetry are analyzed, and the detailed numerical model is derived. The proposed analytical method is validated with NASA’s Surface Water and Ocean Topography (SWOT) project error budget, and the Root-Mean-Square Errors (RMSEs) are in good agreement (0.2486 and 0.2470 cm on a 0.5 km2 grid, respectively). Instead of analysis for a typical project, the proposed method can be applied to different radar parameters under multiple sea states. The RMSEs of Ka-band under low sea state, moderate sea state, and high sea state are 0.2670, 1.3154, and 6.6361 cm, respectively. Moreover, the RMSEs of X-band and Ku-band are also simulated and presented. The experimental results demonstrate that the dynamic wave-related errors of InSAR altimetry are not sensitive to the frequencies but are sensitive to the sea states. The error compensation method is necessary for moderate and higher sea states for centimetric accuracy requirements. This can provide feasible suggestions on system design and error budget for the future interferometric wide-swath altimeter.

scholarly journals Long-Term Observations of Microwave Brightness Temperatures over a Metropolitan Area: Comparison of Radiometric Data and Spectra Simulated with the Use of Radiosonde Measurements

2021 ◽  
Vol 13 (11) ◽  
pp. 2061
Author(s):  
Mikhail V. Belikovich ◽  
Mikhail Yu. Kulikov ◽  
Dmitry S. Makarov ◽  
Natalya K. Skalyga ◽  
Vitaly G. Ryskin ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Elevation Angle ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Systematic Bias ◽  
Tropospheric Temperature ◽  
Absorption Model ◽  
60 Ghz ◽  
Error Budget ◽  
The Difference

Ground-based microwave radiometers are increasingly used in operational meteorology and nowcasting. These instruments continuously measure the spectra of downwelling atmospheric radiation in the range 20–60 GHz used for the retrieval of tropospheric temperature and water vapor profiles. Spectroscopic uncertainty is an important part of the retrieval error budget, as it leads to systematic bias. In this study, we analyze the difference between observed and simulated microwave spectra obtained from more than four years of microwave and radiosonde observations over Nizhny Novgorod (56.2° N, 44° E). We focus on zenith-measured and elevation-scanning data in clear-sky conditions. The simulated spectra are calculated by a radiative transfer model with the use of radiosonde profiles and different absorption models, corresponding to the latest spectroscopy research. In the case of zenith-measurements, we found a systematic bias (up to ~2 K) of simulated spectra at 51–54 GHz. The sign of bias depends on the absorption model. A thorough investigation of the error budget points to a spectroscopic nature of the observed differences. The dependence of the results on the elevation angle and absorption model can be explained by the basic properties of radiative transfer and by cloud contamination at elevation angles.

Optical engineering requirements for the LISA wavefront error budget

1998 ◽  
Author(s):  
Martin Caldwell ◽  
Paul McNamara ◽  
Anna Glennmar
Keyword(s):  
Error Budget ◽  
Optical Engineering ◽  
Wavefront Error

scholarly journals M&m's: an error budget and performance simulator code for polarimetric systems

2011 ◽  
Author(s):  
Maria de Juan Ovelar ◽  
Frans Snik ◽  
Christoph U. Keller
Keyword(s):  
Error Budget ◽  
And Performance

A CdTe Position Sensitive Detector for a Hard X-and Gamma-Ray Wide Field Camera

1997 ◽  
Vol 487 ◽  
Author(s):  
E. Caroli ◽  
G. Bertuccio ◽  
G. De Cesare ◽  
A. Donati ◽  
W. Dusi ◽  
...  
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Basic Element ◽  
Medium Size ◽  
Electromagnetic Spectrum ◽  
Wide Field ◽  
Cdte Detector ◽  
Important Region ◽  
Expected Performance ◽  
Position Sensitive

AbstractAn important region of the electromagnetic spectrum for astrophysics is the hard X- and gamma ray band between 10 keV and a few MeV, where several processes occur in a wide variety of objects and with different spatial distribution and time scales. In order to fulfill the observational requirements in this energy range and taking into account the opportunities given by small/medium size missions (e.g. on the ISS), we have proposed a compact, wide field camera based on a thick (1 cm) position sensitive CdTe detector (PSD). The detector is made of an array of 128×96 CdTe microspectrometers with a pixel size of 2×2 mm2. The basic element of the PSD is the linear module that is an independent detection unit with 32 CdTe crystals and monolithic front-electronics (ASIC) supported by a thin (300 μm) ceramic layer. The expected performance of the PSD over the operative energy range and some of the required ASIC functionality are presented and discussed.

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