Luciana Da Silva | Universidade Estadual de Campinas (original) (raw)

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Thesis Chapters by Luciana Da Silva

Nowadays, the most central themes of Geodesy are linked to the provision of a unique Global Refer... more Nowadays, the most central themes of Geodesy are linked to the provision of a
unique Global Reference System, to which can be tied of unique form and with
accurately the geometrical and physical global changes. In this sense, the bases of
the future Global Geodetic Reference Frame (GGRF) have been established by the
United Nations on February 26, 2015 with the Resolution (A/RES/69/266). The
GGRF aims at better structuring Earth Observation Systems currently with prospects
of the global changes determination at the level of one part per billion, considering
several geometric and physical parameters. In the Global Geodetic Observing
System (GGOS) of the International Association of Geodesy (IAG) the referred
accuracy presuppose is estimated that to be achieved by 2020. In July 2015 IAG
established the International Height Reference System (IHRS). In this context, it is
intended that the International Height Reference Frame (IHRF), realization of the
IHRS, has an overall consistency of at least one centimeter in its realization and
space/temporal control in the order of millimeter per year. The GRRF is, now,
understood as the association of the traditional International Terrestrial Reference
Frame with the IHRF. National Vertical Data worldwide must be linked to the IHRF.
Considering these aspects, it was analyzed the temporal evolution of the Imbituba
Brazilian Vertical Datum utilizing tide gauge data from the Sea Level of the
databases: Permanent Service for Mean Sea Level (1948 to 1968), University of
Hawaii Sea Level Center (2001 to 2007) and Permanent Tide Gauge Network for
Geodesy (2006 to 2016), as well as data from different altimetry missions from 1991
to 2015 obtained from the database of the Deutsches Geodätisches
Forschungsinstitut - Open Altimeter Database. Additionally, the temporal series
obtained from GNSS continuous positioning from the period 2007 to 2016 were used,
which were used to modeling the local movements of the crust. The velocity models
for South America indicated by SIRGAS were used, as well as geological and
geophysical models. These were used for validation of GNSS processing and for
comparison of the up component of Imbituba. The results allowed discriminating the
crust movements in relation to the sea level. To achieve it, the trend of sea level
variation evidenced by the tide gauge was used, as well as the variation of the
vertical component obtained with the GNSS processing and the Sea Surface Height
(SSH) obtained from the altimeter satellite data. After that the analyzing of the trend
for the estimation of the geocentric positioning of the Imbituba Brazilian Vertical
Datum, the following results were obtained: 5.26 mm/year the trend of the tide gauge;
-3.02 mm/year the subsidence of the up component; and 2.23 mm/year the trend of
the SSH. There is a trend of MSL elevation in the region of Imbituba Brazilian Vertical
Datum by the determination the resulting temporal variation approximately + 2.24
mm/year ± 0.4 mm / year.