Performance of Earth Troposphere Calibration Measurements with the Advanced Water Vapor Radiometer for the Juno Gravity Science Investigation

The error in VLBI estimates of baseline length caused by unmodelled variations in the propagation path through the atmosphere is greater for longer baselines. We present and discuss series of estimates of baseline lengths obtained using different methods to correct for the propagation delay caused by atmospheric water vapor. The main methods are use of data from a water-vapor radiometer (WVR) and Kalman-filtering of the VLBI data themselves to estimate the propagation delay. Since the longest timespan of WVR data associated with geodetic VLBI experiments was obtained at the Onsala Space Observatory in Sweden, we present results for the following three baselines: (1) Onsala–Wettzell, FRG (920 km), (2) Onsala–Haystack/Westford, MA (5600 km), and (3) Onsala–Owens Valley (7914 km).

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MIAWARA-C, a new ground based water vapor radiometer for measurement campaigns

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-3-2389-2010 ◽

2010 ◽

Vol 3 (3) ◽

pp. 2389-2432

Author(s):

C. Straub ◽

A. Murk ◽

N. Kaempfer

Keyword(s):

Water Vapor ◽

Middle Atmosphere ◽

Horn Antenna ◽

Profile Measurement ◽

Correlation Receiver ◽

Water Vapor Radiometer ◽

Set Up ◽

Compact Design ◽

Crucial Parameter ◽

Measurement Campaigns

Abstract. In this paper a new 22 GHz water vapor spectro-radiometer which has been specifically designed for profile measurement campaigns of the middle atmosphere is presented. The instrument is of a compact design and has a simple set up procedure. It can be operated as a standalone instrument as it maintains its own weather station and a calibration scheme that does not rely on other instruments or the use of liquid nitrogen. The optical system of MIAWARA-C combines a choked gaussian horn antenna with a parabolic mirror which reduces the size of the instrument in comparison with currently existing radiometers. For the data acquisition a correlation receiver is used together with a digital cross correlating spectrometer. The complete backend section, including the computer, is located in the same housing as the instrument. The receiver section is temperature stabilized to avoid gain fluctuations. Calibration of the instrument is achieved through a balancing scheme with the sky used as the cold load and the tropospheric properties are determined by performing regular tipping curves. Since MIAWARA-C is used in measurement campaigns it is important to be able to determine the elevation pointing in a simple manner as this is a crucial parameter in the calibration process. Here we present two different methods; scanning the sky and the Sun. Finally, we report on the first spectra and retrieved water vapor profiles acquired during the Lapbiat campaign at Sodankylä Geophysical Observatory. The performance of MIAWARA-C is validated here by comparison of the presented profiles against the equivalent profiles from the Microwave Limb Sounder on the EOS/Aura satellite.

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Precipitable water vapor on the Tibetan Plateau estimated by GPS, water vapor radiometer, radiosonde, and numerical weather prediction analysis and its impact on the radiation budget

Journal of Geophysical Research Atmospheres ◽

10.1029/2004jd005715 ◽

2005 ◽

Vol 110 (D17) ◽

Cited By ~ 25

Author(s):

J. Liu

Keyword(s):

Water Vapor ◽

Tibetan Plateau ◽

Numerical Weather Prediction ◽

Weather Prediction ◽

Precipitable Water ◽

Radiation Budget ◽

The Tibetan Plateau ◽

Prediction Analysis ◽

Numerical Weather ◽

Water Vapor Radiometer

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GFO water vapor radiometer

10.2514/6.1993-4230 ◽

1993 ◽

Author(s):

Muhammad Malik

Keyword(s):

Water Vapor ◽

Water Vapor Radiometer

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Evaluation of Empirical Tropospheric Models Using Satellite-Tracking Tropospheric Wet Delays with Water Vapor Radiometer at Tongji, China

Sensors ◽

10.3390/s16020186 ◽

2016 ◽

Vol 16 (2) ◽

pp. 186 ◽

Cited By ~ 9

Author(s):

Miaomiao Wang ◽

Bofeng Li

Keyword(s):

Water Vapor ◽

Satellite Tracking ◽

Water Vapor Radiometer

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Long-term observation of midlatitude quasi 2-day waves by a water vapor radiometer

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-12061-2018 ◽

2018 ◽

Vol 18 (16) ◽

pp. 12061-12074 ◽

Cited By ~ 2

Author(s):

Martin Lainer ◽

Klemens Hocke ◽

Niklaus Kämpfer

Keyword(s):

Water Vapor ◽

Large Fraction ◽

Dynamical Behavior ◽

Measurement Data ◽

Data Set ◽

Water Vapor Radiometer ◽

Long Term Observation ◽

Scientific Value ◽

High Degree

Abstract. A mesospheric water vapor data set obtained by the middle atmospheric water vapor radiometer (MIAWARA) close to Bern, Switzerland (46.88∘ N, 7.46∘ E) during October 2010 to September 2017 is investigated to study the long-term evolution and variability of quasi 2-day waves (Q2DWs). We present a climatological overview and an insight on the dynamical behavior of these waves with the occurring spectrum of periods as seen from a midlatitude observation site. Such a large and nearly continuous measurement data set as ours is rare and of high scientific value. The core results of our investigation indicate that the activity of the Q2DW manifests in burst-like events and is higher during winter months (November–February) than during summer months (May–August) for the altitude region of the mesosphere (up to 0.02 hPa in winter and up to 0.05 hPa in summer) accessible for the instrument. Single Q2DW events reach at most about 0.8 ppm in the H2O amplitudes. Further, monthly mean Q2DW amplitude spectra are presented and reveal a high-frequency variability between different months. A large fraction of identified Q2DW events (20 %) develop periods between 38 and 40 h. Further, we show the temporal evolution of monthly mean Q2DW oscillations continuously for all months and separated for single months over 7 years. The analysis of autobicoherence spectra gives evidence that Q2DWs are sometimes phase coupled to diurnal oscillations to a high degree and to waves with a period close to 18 h.

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