Water Vapor Radiometry at the Onsala Space Observatory from 1980 to 1987

1988 ◽  
pp. 547-548
Author(s):  
J. M. Johansson ◽  
G. Elgered ◽  
B. O. Ronnang
Keyword(s):  
Water Vapor ◽  
Space Observatory ◽  
Onsala Space Observatory

scholarly journals Methods of Correction for the “Wet” Atmosphere in Estimating Baseline Lengths from VLBI

1988 ◽  
Vol 129 ◽  
pp. 543-544
Author(s):  
G. Elgered ◽  
J. L. Davis ◽  
T. A. Herring ◽  
I. I. Shapiro
Keyword(s):  
Water Vapor ◽  
Propagation Delay ◽  
Propagation Path ◽  
Baseline Length ◽  
Space Observatory ◽  
Owens Valley ◽  
Use Of Data ◽  
Onsala Space Observatory ◽  
Vlbi Data ◽  
Water Vapor Radiometer

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).

scholarly journals Water Vapor Radiometry at the Onsala Space Observatory from 1980 to 1987

1988 ◽  
Vol 129 ◽  
pp. 547-548 ◽  
Author(s):  
J. M. Johansson ◽  
G. Elgered ◽  
B. O. Rönnäng
Keyword(s):  
Water Vapor ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Space Observatory ◽  
Brightness Temperatures ◽  
Onsala Space Observatory ◽  
Water Vapor Radiometer ◽  
Sky Brightness

Variations in atmospheric water vapor are difficult to correct for in geodetic, astrometric, and mm-wave astronomy VLBI. The use of a water vapor radiometer (WVR) has given promising results. The algorithm which relates the sky brightness temperatures observed by the WVR to the delay caused by atmopheric water vapor is discussed. Examples of WVR measurements made at the Onsala Space Observatory from 1980 to 1987 are presented.

scholarly journals Sensing atmospheric structure: Tropospheric tomographic results of the small-scale GPS campaign at the Onsala Space Observatory

2000 ◽  
Vol 52 (11) ◽  
pp. 941-945 ◽  
Author(s):  
A. Flores ◽  
L. P. Gradinarsky ◽  
P. Elósegui ◽  
G. Elgered ◽  
J. L. Davis ◽  
...  
Keyword(s):  
Small Scale ◽  
Space Observatory ◽  
Atmospheric Structure ◽  
Onsala Space Observatory

scholarly journals Observing UT1-UTC with VGOS

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Rüdiger Haas ◽  
Eskil Varenius ◽  
Saho Matsumoto ◽  
Matthias Schartner
Keyword(s):  
Standard Deviation ◽  
Reference Frame ◽  
Earth Rotation ◽  
Space Observatory ◽  
International Earth Rotation ◽  
Onsala Space Observatory ◽  
X Band ◽  
First Results

AbstractWe present first results for the determination of UT1-UTC using the VLBI Global Observing System (VGOS). During December 2019 through February 2020, a series of 1 h long observing sessions were performed using the VGOS stations at Ishioka in Japan and the Onsala twin telescopes in Sweden. These VGOS-B sessions were observed simultaneously to standard legacy S/X-band Intensive sessions. The VGOS-B data were correlated, post-correlation processed, and analysed at the Onsala Space Observatory. The derived UT1-UTC results were compared to corresponding results from standard legacy S/X-band Intensive sessions (INT1/INT2), as well as to the final values of the International Earth Rotation and Reference Frame Service (IERS), provided in IERS Bulletin B. The VGOS-B series achieves 3–4 times lower formal uncertainties for the UT1-UTC results than standard legacy S/X-band INT series. The RMS agreement w.r.t. to IERS Bulletin B is slightly better for the VGOS-B results than for the simultaneously observed legacy S/X-band INT1 results, and the VGOS-B results have a small bias only with the smallest remaining standard deviation.

3.3 GHz Ground-State Transitions of CH towards Southern HII Regions–1. An Atlas of CH Profiles

1985 ◽  
Vol 6 (1) ◽  
pp. 6-33 ◽  
Author(s):  
J. B. Whiteoak ◽  
F. F. Gardner ◽  
Gwenyth A. Manefield ◽  
B. Höglund ◽  
L. E. B. Johansson
Keyword(s):  
Radio Telescope ◽  
Ground State ◽  
Hii Regions ◽  
State Transitions ◽  
Space Observatory ◽  
Onsala Space Observatory

SummaryThe Parkes 64-m radio telescope equipped with a 3 GHz maser on loan from the Onsala Space Observatory has been used to observe the three ground-state transitions of CH (at 3264, 3335 and 3349 MHz) towards a total of 74 HII regions, mostly at southern declinations. In this paper the regions and related characteristics are listed, and the CH spectra displayed.

Molecular Line Observations at Parkes with a 3 GHz Maser

1979 ◽  
Vol 3 (5) ◽  
pp. 321-323 ◽  
Author(s):  
B. Höglund ◽  
J. B. Whiteoak ◽  
F. F. Gardner
Keyword(s):  
Spectral Line ◽  
Radio Telescope ◽  
Ground State ◽  
State Transitions ◽  
Space Observatory ◽  
Molecular Line ◽  
System Sensitivity ◽  
Onsala Space Observatory

A 3 GHz maser from the Onsala Space Observatory, Sweden, is currently at Parkes on a long-term loan basis. So far, it has been used on the 64-m radio telescope for a two-week period of spectral-line observations in February 1979, providing a system sensitivity far superior to that previously available at the same frequency. The observed lines were the ground-state transitions of CH at 3264, 3335 and 3349 MHz, the 211 – 212 transition of H2CS at 3139 MHz, and the 211-212 transition of CH3CHO at 3195 MHz.

THE ANALYSIS OF THE STABILITY OF PERMANENT GPS STATION VILNIUS (VLNS) / NUOLAT VEIKIANČIOS VILNIAUS (VLNS) GPS STOTIES STABILUMO ANALIZĖ / АНАЛИЗ СТАБИЛЬНОСТИ ПОСТОЯННО ДЕЙСТВУЮЩЕЙ СТАНЦИИ ГПС VILNIUS (VLNS)

2011 ◽  
Vol 37 (3) ◽  
pp. 129-134 ◽  
Author(s):  
Eimuntas Paršeliūnas ◽  
Ričardas Kolosovskis ◽  
Raimundas Putrimas ◽  
Arūnas Būga
Keyword(s):  
Earth Rotation ◽  
Current Status ◽  
Main Task ◽  
Technical Equipment ◽  
Space Observatory ◽  
International Earth Rotation Service ◽  
Gps Satellites ◽  
Onsala Space Observatory ◽  
The Stability ◽  
Gps Station

Lithuania has been participating in the activities of the EUREF permanent network since 1996, when GPS station VILNIUS started regular continuous tracking of GPS satellites. The GPS station was established with a help of the Onsala Space Observatory (Sweden) and was mounted in the territory of Vilnius international airport (Lithuania). Four character identifier VLNS and DOMES number 10801M001 were assigned to VILNIUS GPS station by the International Earth Rotation Service in 1999. VILNIUS station is operated and maintained by the Institute of Geodesy of Vilnius Technical University. The main task of the permanent VLNS GPS station is to take part in EUREF activities and serve as reference to GPS campaigns in Lithuania. The aim of this paper is to describe the evolution and current status of the technical equipment of VILNIUS station. The paper also presents the analysis of data quality and a few years interval of coordinate determination at VLNS within the EUREF network. Santrauka EUREF nuolat veikiančių stočių tinklo veikloje Lietuva dalyvauja nuo 1996 m., kai GPS VILNIAUS stotis pradėjo reguliarius matavimus iš GPS palydovų. Stotis įsteigta padedant Onsalos kosmoso observatorijai (Švedija). GPS stotis įrengta Vilniaus tarptautinio oro uosto teritorijoje 1999 metais. Tarptautinė žemės sukimositarnyba stočiai suteikė keturių simbolių identifikatorių VLNS ir DOMES numerį 10801M001. GPS VILNIAUS stotį prižiūri ir valdo Vilniaus Gedimino technikos universiteto Geodezijos instituto specialistai. Pagrindinis stoties uždavinys yra dalyvauti EUREF veikloje, ir tai turi būti atraminis geodezinis punktas GPS kampanijoms Lietuvoje. Straipsnio tikslas – aprašyti dabartinę techninės įrangos būklę ir jos tobulinimo eigą. Pateikiama kelerių metų matavimo duomenų kokybės analizė ir nustatytos koordinatės EUREF tinkle. Резюме В проекте сети постоянно действующих станций ГПС EUREF Литва участвует с 1996 г., когда станция VILNIUS стала производить постоянные измерения со спутников ГПС. Станция была основана при помощи Онсольской космической oбсерватории (Швеция). Станция ГПС установлена на территории Вильнюсского международного аэропорта. В 1999 г. Международная служба вращения Земли присвоила станции код VLNS и DOMES номер 10801М001. Станцией управляют специалисты из Геодезического института Вильнюсского технического университета им. Гедиминаса. Главной задачей станции является участие в мероприятиях EUREF, а также быть основным геодезическим пунктом в кампаниях ГПС на территории Литвы. В статье преследовалась цель описать состояние технического оборудования станции и меры по его улучшению. Представлен анализ данных измерений ГПС за несколько лет и определены геодезические координаты в сети EUREF.

scholarly journals SEPIA – a new single pixel receiver at the APEX telescope

2018 ◽  
Vol 612 ◽  
pp. A23 ◽  
Author(s):  
V. Belitsky ◽  
I. Lapkin ◽  
M. Fredrixon ◽  
D. Meledin ◽  
E. Sundin ◽  
...  
Keyword(s):  
State Of The Art ◽  
Noise Temperature ◽  
Intermediate Frequency ◽  
Space Observatory ◽  
Frequency Channel ◽  
Current Frequency ◽  
Onsala Space Observatory ◽  
Hardware Description ◽  
And Performance ◽  
Single Pixel

Context. We describe the new Swedish-ESO PI Instrument for APEX (SEPIA) receiver, which was designed and built by the Group for Advanced Receiver Development (GARD), at Onsala Space Observatory (OSO) in collaboration with ESO. It was installed and commissioned at the APEX telescope during 2015 with an ALMA Band 5 receiver channel and updated with a new frequency channel (ALMA Band 9) in February 2016. Aim. This manuscript aims to provide, for observers who use the SEPIA receiver, a reference in terms of the hardware description, optics and performance as well as the commissioning results. Methods. Out of three available receiver cartridge positions in SEPIA, the two current frequency channels, corresponding to ALMA Band 5, the RF band 158–211 GHz, and Band 9, the RF band 600–722 GHz, provide state-of-the-art dual polarization receivers. The Band 5 frequency channel uses 2SB SIS mixers with an average SSB noise temperature around 45 K with IF (intermediate frequency) band 4–8 GHz for each sideband providing total 4 × 4 GHz IF band. The Band 9 frequency channel uses DSB SIS mixers with a noise temperature of 75–125 K with IF band 4–12 GHz for each polarization. Results. Both current SEPIA receiver channels are available to all APEX observers.

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