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Current state of art of satellite altimetry

Łyszkowicz A. B., Bernatowicz A.

Geodesy and Cartography

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2017

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Vol. 66, no. 2

259--270

EN

One of the fundamental problems of modern geodesy is precise defi nition of the gravitational fi eld and its changes in time. This is essential in positioning and navigation, geophysics, geodynamics, oceanography and other sciences related to the climate and Earth’s environment. One of the major sources of gravity data is satellite altimetry that provides gravity data with almost 75% surface of the Earth. Satellite altimetry also provides data to study local, regional and global geophysical processes, the geoid model in the areas of oceans and seas. This technique can be successfully used to study the ocean mean dynamic topography. The results of the investigations and possible products of altimetry will provide a good material for the GGOS (Global Geodetic Observing System) and institutions of IAS (International Altimetry Service). This paper presents the achievements in satellite altimetry in all the above disciplines obtained in the last years. First very shorly basic concept of satellite altimetry is given. In order to obtain the highest accuracy on range measurements over the ocean improved of altimetry waveforms performed on the ground is described. Next, signifi cant improvements of sea and ocean gravity anomalies models developed presently is shown. Study of sea level and its extremes examined, around European and Australian coasts using tide gauges data and satellite altimetry measurements were described. Then investigations of the phenomenon of the ocean tides, calibration of altimeters, studies of rivers and ice-sheets in the last years are given.

2

Current State of Art of Satellite Altimetry

Łyszkowicz A., Bernatowicz A.

Annual of Navigation

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2017

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No. 24

31--47

EN

One of the fundamental problems of modern geodesy is precise definition of the gravitational field and its changes in time. This is essential in positioning and navigation, geophysics, geodynamics, oceanography and other sciences related to the climate and Earth’s environment. One of the major sources of gravity data is satellite altimetry that provides gravity data with almost 75% surface of the Earth. Satellite altimetry also provides data to study local, regional and global geophysical processes, the geoid model in the areas of oceans and seas. This technique can be successfully used to study the ocean mean dynamic topography. The results of the investigations and possible products of altimetry will provide a good material for the GGOS (Global Geodetic Observing System) and institutions of IAS (International Altimetry Service). This paper presents the achievements in satellite altimetry in all the above disciplines obtained in the last years.

PL

Jednym z podstawowych problemów współczesnej geodezji jest dokładne określenie pola grawitacyjnego i jego zmian w czasie. Ma to zasadnicze znaczenie dla zastosowań w pozycjonowaniu i nawigacji, w geofizyce, geodynamice, oceanografii i innych naukach związanych z klimatem i środowiskiem Ziemi. Jednym z głównych źródeł danych grawimetrycznych jest altimetria satelitarna, która dostarcza dane grawimetryczne z prawie 75% powierzchni globu ziemskiego. Altimetria satelitarna dostarcza również dane do badania lokalnych, regionalnych i globalnych procesów geofizycznych, modelu geoidy na obszarach mórz i oceanów oraz średniej dynamicznej topografii oceanów. Wyniki badań i potencjalne produkty danych altimetrycznych mają stanowić materiał dla Globalnego Geodezyjnego Systemu Obserwacji GGOS (Global Geodetic Observing System) i instytucji IAS (International Altimetry Service).

3

LAGEOS Sensitivity to Ocean Tides

Sośnica K.

Acta Geophysica

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2015

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Vol. 63, no. 4

1181--1203

EN

Satellite Laser Ranging (SLR) to LAGEOS has a remarkable contribution to high-precise geodesy and geodynamics through deriving and validating various global geophysical models. This paper validates ocean tide models based on the analysis of satellite altimetry data, coastal tide gauges, and hydrodynamic data, i.e., CSR3.0, TOPEX4.0, CSR4.0A, FES2004, GOT00.2, and the CSRC Schwiderski model. LAGEOS orbits and SLR observation residuals from solutions based on different ocean tide models are compared and examined. It is found that LAGEOS orbits are sensitive to tidal waves larger than 5 mm. The analysis of the aliasing periods of LAGEOS orbits and tidal waves reveals that, in particular, the tidal constituent S2 is not well established in the recent ocean tide models. Some of the models introduce spurious peaks to empirical orbit parameters, which can be associated with S2, Sa, and K2 tidal constituents, and, as a consequence, can be propagated to fundamental parameters derived from LAGEOS observations.