Fluctuation component of atmospheric noise temperature

1963 ◽  
Vol 51 (3) ◽  
pp. 477-477 ◽  
Author(s):  
T. Orhaug
Keyword(s):  
Noise Temperature ◽  
Atmospheric Noise ◽  
Fluctuation Component

The influence of unintentional radio interference on the equipment operation quality of satellite radio navigation systems consumers

2020 ◽  
pp. 165-170
Keyword(s):  
Underlying Surface ◽  
Navigation Systems ◽  
Signal Attenuation ◽  
Radio Navigation ◽  
Equipment Operation ◽  
Atmospheric Noise ◽  
Detection Mode ◽  
Signal Mode ◽  
Cosmic Noise

The analysis an influence of reflections from the underlying surface, atmospheric noise, the Earth’s surface, cosmic noise and signal attenuation of the signal the atmosphere, as well as the flight dynamics of the aircraft (AC) on the signal/noise ratio and, accordingly, on the accuracy of AC navigation definitions by using consumer equipment of the satellite radio navigation systems. The analysis an influence of reflections from the underlying surface on the equipment operation quality of the satellite radio navigation systems consumers is carried out by using the Beckman model, in accordance with the earth’s surface appears to consist of flat faces with an arbitrary slope. It is noted that reflections from the underlying surface have a greater effect on the quality of functioning of the consumer equipment of the satellite radio navigation systems in the tracking signal mode than in the detection mode. In this case, the influence of reflections increases with decreasing flight altitude and an increase in the angle of heel of the AC in the direction of the navigation spacecraft.

Noise temperature distribution of superconducting hot electron bolometer mixers

2020 ◽  
Vol 29 (5) ◽  
pp. 058505
Author(s):  
Kang-Min Zhou ◽  
Wei Miao ◽  
Yue Geng ◽  
Yan Delorme ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Noise Temperature ◽  
Hot Electron ◽  
Hot Electron Bolometer

scholarly journals A New 21-cm Line Survey of the LMC

1984 ◽  
Vol 108 ◽  
pp. 395-396
Author(s):  
K. Rohlfs ◽  
J. Kreitschmann ◽  
J. V. Feitzinger
Keyword(s):  
Noise Temperature ◽  
Beam Width ◽  
Main Beam ◽  
Corrugated Waveguide ◽  
Line Survey ◽  
Single Polarization ◽  
Switching Mode ◽  
Half Power ◽  
Channel Separation ◽  
Made In

The measurements were made in Feb. 1982 with the Parkes 64 m telescope using a corrugated waveguide horn with total half-power beam width of 15′, the first sidelobes being 19 dB down, resulting in an aperture efficiency ηA=0.53±0.007, a main beam efficiency of ηmb=0.80±0.005 and a ratio of source flux to antenna temperature of Γ=0.62±0.1 K/Jy (Murray, priv. comm.). A cooled two channel FET frontend used in the frequency switching mode with Δν = 2 MHz resulted in a system noise temperature at zenith of Tsyst = 40 K for one channel and Tsyst = 50 K for the other. Each frontend channel received a single polarization mode, and this radiation was then further analysed in a 2 × 512 channel autocorrelation spectrometer set at a channel separation of 3.906 KHz corresponding to a velocity resolution of V = 0.824 km s−1. Hanning smoothed this resulted in a σT = 0.05 K for the average of both polarization.

scholarly journals Analysis of noise temperature sensitivity for the design of a broadband thermal noise primary standard

Metrologia ◽  
2012 ◽  
Vol 49 (4) ◽  
pp. 538-551 ◽  
Author(s):  
Alejandro Díaz-Morcillo ◽  
Antonio Lozano-Guerrero ◽  
Jaime Fornet-Ruiz ◽  
Juan Monzó-Cabrera
Keyword(s):  
Temperature Sensitivity ◽  
Thermal Noise ◽  
Primary Standard ◽  
Noise Temperature

scholarly journals ARIS-Campaign: intercomparison of three ground based 22 GHz radiometers for middle atmospheric water vapor at the Zugspitze in winter 2009

2011 ◽  
Vol 4 (9) ◽  
pp. 1979-1994 ◽  
Author(s):  
C. Straub ◽  
A. Murk ◽  
N. Kämpfer ◽  
S. H. W. Golchert ◽  
G. Hochschild ◽  
...  
Keyword(s):  
Water Vapor ◽  
Noise Temperature ◽  
Rotational Transition ◽  
Atmospheric Water Vapor ◽  
Transition Line ◽  
Applied Physics ◽  
Atmospheric Water ◽  
Max Planck ◽  
Institute Of Technology ◽  
University Of Bern

Abstract. This paper presents the Alpine Radiometer Intercomparison at the Schneefernerhaus (ARIS), which took place in winter 2009 at the high altitude station at the Zugspitze, Germany (47.42° N, 10.98° E, 2650 m). This campaign was the first direct intercomparison between three new ground based 22 GHz water vapor radiometers for middle atmospheric profiling with the following instruments participating: MIRA 5 (Karlsruhe Institute of Technology), cWASPAM3 (Max Planck Institute for Solar System Research, Katlenburg-Lindau) and MIAWARA-C (Institute of Applied Physics, University of Bern). Even though the three radiometers all measure middle atmospheric water vapor using the same rotational transition line and similar fundamental set-ups, there are major differences between the front ends, the back ends, the calibration concepts and the profile retrieval. The spectrum comparison shows that all three radiometers measure spectra without severe baseline artifacts and that the measurements are in good general agreement. The measurement noise shows good agreement to the values theoretically expected from the radiometer noise formula. At the same time the comparison of the noise levels shows that there is room for instrumental and calibration improvement, emphasizing the importance of low elevation angles for the observation, a low receiver noise temperature and an efficient calibration scheme. The comparisons of the retrieved profiles show that the agreement between the profiles of MIAWARA-C and cWASPAM3 with the ones of MLS is better than 0.3 ppmv (6%) at all altitudes. MIRA 5 has a dry bias of approximately 0.5 ppm (8%) below 0.1 hPa with respect to all other instruments. The profiles of cWASPAM3 and MIAWARA-C could not be directly compared because the vertical region of overlap was too small. The comparison of the time series at different altitude levels show a similar evolution of the H2O volume mixing ratio (VMR) for the ground based instruments as well as the space borne sensor MLS.

A W-band low-noise amplifier with 22K noise temperature

2009 ◽  
Author(s):  
Eric W. Bryerton ◽  
Xiaobing Mei ◽  
Young-Min Kim ◽  
William Deal ◽  
Wayne Yoshida ◽  
...  
Keyword(s):  
Noise Temperature ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
W Band ◽  
Noise Amplifier
Sign in / Sign up

Export Citation Format

Share Document