Contribution of Tide Gauges for the Determination of W0 in Canada

2014 ◽  
pp. 241-248 ◽  
Author(s):  
T. Hayden ◽  
E. Rangelova ◽  
M. G. Sideris ◽  
M. Véronneau
Keyword(s):  
Tide Gauges

scholarly journals Determination of geopotential value W 0 L at Polish tide gauges from GNSS data and geoid model

2016 ◽  
Vol 52 (4) ◽  
pp. 527-534 ◽  
Author(s):  
Joanna Kuczynska-Siehien ◽  
Adam Lyszkowicz ◽  
Katarzyna Stepniak ◽  
Marta Krukowska
Keyword(s):  
Tide Gauges ◽  
Geoid Model ◽  
Gnss Data

On the History of Recording Tide Gauges

1972 ◽  
Vol 73 ◽  
pp. 26-34 ◽  
Author(s):  
Wolfgang Matthäus
Keyword(s):  
Tide Gauge ◽  
The United States ◽  
Water Levels ◽  
Level Gauge ◽  
Tide Gauges ◽  
European Continent ◽  
Sea Levels ◽  
History Of ◽  
The Baltic

SynopsisRecords of water levels date from the first hydrospheric observations. The levels of inland and coastal waters are recorded with the use of tide gauges of various types and construction. The float-level gauge, however, is by far the most frequently used.The oldest self-recording tide gauge was constructed by Henry R. Palmer, civil engineer of the London Dock Company, in 1831. A float resting on the water is placed in a well communicating with the river. The motion of the water surface is transmitted to the recording machine by wheels and shafts which act on a pencil rack. As the water level rises and falls, by the combined motions of a clock and the tide the pencil produces a line as a function of time.Even today this principle is still used for float-level gauges. It represents the basis of the modern tide gauges for observing sea levels and their variations.In 1831 we find another construction by Mitchell, which was erected in the Sheerness dockyard. A few years later Thomas G. Bunt developed a tide gauge, which was used on the eastern bank of the river Avon near Bristol from 1837 to 1872.In 1834 the first self-recording gauge was erected in France, near Le Havre. On the other continents the first installations were established in Algiers (1834), in the United States and in India (1846), and in Australia (1858)An installation in Hamburg (1861), which was developed by F. H. Reitz the engineer, is identified as the first German construction.In 1870 fifteen tide gauges were known on the shores of the European continent (except the British Isles). By 1883 Carlos Ibañez was using information from approximately 67 tide gauge stations for the determination of the mean sea level around the European mainland. Today we find more than 300 installations in Europe, about three-quarters of which are working in north-western European waters and in the Baltic.

scholarly journals Overlapping sea level time series measured using different technologies: an example from the REDMAR Spanish network

2014 ◽  
Vol 14 (3) ◽  
pp. 589-610 ◽  
Author(s):  
B. Pérez ◽  
A. Payo ◽  
D. López ◽  
P. L. Woodworth ◽  
E. Alvarez Fanjul
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Tide Gauge ◽  
Sampling Strategies ◽  
Tide Gauges ◽  
Sea Levels ◽  
Tsunami Detection ◽  
The Impact

Abstract. This paper addresses the problems of overlapping sea level time series measured using different technologies and sometimes from different locations inside a harbour. The renovation of the Spanish REDMAR (RED de MAReógrafos) sea level network is taken here as an example of the difficulties encountered: up to seventeen old tide gauge stations have been replaced by radar tide gauges all around the Spanish coast, in order to fulfil the new international requirements on tsunami detection. Overlapping periods between old and new stations have allowed the comparison of records in different frequency ranges and the determination of the impact of this change of instrumentation on the long-term sea level products such as tides, surges and mean sea levels. The differences encountered are generally within the values expected, taking into account the characteristics of the different sensors, the different sampling strategies and sometimes the different locations inside the harbours. However, our analysis has also revealed in some cases the presence of significant scale errors that, overlapping with datum differences and uncertainties, as well as with hardware problems in many new radar gauges, may hinder the generation of coherent and continuous sea level time series. Comparisons with nearby stations have been combined with comparisons with altimetry time series close to each station in order to better determine the sources of error and to guarantee the precise relationships between the sea level time series from the old and the new tide gauges.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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