SPECIAL STUDY GROUP 3.186:
ˇ§ALTIMETRY DATA PROCSESSING FOR GRAVITY, GEOID AND
SEA SURFACE TOPOGRAPHY DETERMINATIONˇ¨
C. Hwang
Introduction
Since the
Seasat mission of 1978, satellite altimetry has found its wide applications in
geodesy, geophysics and oceanography. As new satellite missions such as GFO-1,
ENVISAT JASON-1, and CRYOSAT continue to contribute to the existing data sets
of Seasat, Geosat, ERS-1/2, and TOPEX/POSEDION, more applications will be
exploited. We are in need of more sophisticated data processing techniques to
explore these applications. For example, coastal geoids, gravity anomalies tide
models and bathymetry models derived from satellite altimetry have important
engineering applications, which did not receive much attention in the past. But
exploiting satellite altimetry in coastal areas requires much more
sophisticated correction models and data processing techniques than in the open
oceans. For example, the data and coordinate systems of different satellite
missions should be properly weighted/corrected and unified in order to obtain
an optimal multi-satellite data set for subsequent analyses. Shipborne gravity
data are abundant in many areas of the oceans, and have high quality and good
spatial resolution. They should be combined with altimetry data for global
gravity and geoid computation and estimation of high-degree geopotential model.
Bathymetry model is an important element in, e.g., the general circulation
model of the world oceans and the hydrodynamic tide model, and should be
optimally derived with altimetry and other data. Eddies in coastal areas are
associated with coastal upwelling, which are extremely important for marine
production.
Because of
the need to tackle these problems, SSG3.186 was formed. The members of SSG3.186 are listed in the
following table.
|
Name (country) |
Email address |
|
V. D. Andritsanos (Greece) |
|
|
O. Andersen (Denmark) |
|
|
D. Chao (China) |
|
|
S. A. Chen (Taiwan) |
|
|
X. Deng (Australia) |
|
|
C. Hwang (Taiwan) |
|
|
Y. Fukuda (Japan) |
|
|
J. W. Kim (Korea) |
|
|
J. Klokocnik (Czech Republic) |
|
|
P. Knudsen (Denmark) |
|
|
J. Li (China) |
|
|
P. Hsu (Taiwan) |
|
|
P. Medevedev (Russia) |
|
|
P. Moore (UK) |
|
|
M. Rentsch (Germany) |
|
|
T. Schoene (Germany) |
|
|
C. K. Shum (USA) |
|
|
G. S. Vergos (Canada) |
|
|
G. Venuti (Italy) |
|
|
Y. Wang (USA) |
|
|
Y. Yi (USA) |
Subjects of study
The
selected aims and problems associated with IAG SSG 3.186 are:
1. improving the
quality of coastal altimeter data by improving geophysical corrections,
retracking waveforms and "tuning" altimeter measurements
- promoting engineering
applications of coastal altimetry with high quality coastal geoid, gravity
anomaly, bathymetry, ocean tide and sea surface topography
models from altimetry
- investigating the best method
and the best altimeter data type for computing gravity anomalies, mean sea
surface heights from multi-satellite altimeter data
- developing a best technique
to compute bathymetry from altimeter-derived geoids or gravity anomalies,
with emphasis on the downward continuation and filtering problems
- finding a best strategy and
data sources to combine shipborne gravity/airborne gravity and altimeter
data for generating global and regional gravity anomalies and geoids
- improving orbit accuracies of
altimetric satellites and accuracies of the long wavelength gravity field
by crossover and other methods
- unifying the coordinate
systems between two or more satellite missions for determining long-term
time series of oceanographic parameters
International altimetry workshop
As part of
the activities of SSG 3.186, the ˇ§International Workshop on Satellite
Altimetry for Geodesy, Geophysics and Oceanography: Summer Lecture Series and
Scientific Applicationsˇ¨ was held in Wuhan, China from September 8 to 13,
2002 (see http://space.cv.nctu.edu.tw/altimetryworkshop/altimetry.htm).
This is a joint workshop of
IAG SSG3.186 (chaired by C Hwang) and IAG
Section II (chaired by CK Shum of the Ohio State University), and was hosted by
Wuhan University with Dr JC Li as
the chair of the local organizing committee. The scientific program was organized
by the Scientific Committee chaired by C Hwang. The workshopˇ¦s aim is to offer
free lectures on various subjects of satellite altimetry for beginners and for
advanced researchers, and to provide a forum for presentations and discussions
of latest results in altimetric research. A total of 60 abstracts were received
and 65 people participated in this workshop. These participants are from
Austria (2), Australia (1), Canada (1), China (26), Czech Republic (1), Denmark
(2), France (1), Germany (2), Italy (2), Japan (1), Korean (2), Netherlands
(2), Taiwan (13), UK (1), and USA (7). On September 9 and 10, 2003, the
following five three-hours lectures were delivered:
Lecture 1: Principles of
satellite altimetry and application to sea level change studies, by CK Shum,
Ohio State University, USA
Lecture 2: Ocean tide modeling with altimetry and geodetic
applications, by Kato Matsumoto, National Astronomical Observatory,
Japan
Lecture 3: Marine gravity and
geoid from multi-satellite altimetry and applications, O.B. Andersen, National
Survey and Cadastre, Denmark
Lecture
4: Altimeter waveform retracking for land/ocean use, by P. Berry, De Montfort
University, UK
Lecture
5: Bathymetric estimation from altimetry, by D. T.
Sandwell, Scripps Inst. of Oceanography, USA
On
September 11-13, the following three keynote speeches were delivered:
Speech 1: Geodetic
application of satellite altimetry, W. Bosch, DGFI, Germany
Speech 2: Present-day
sea level change: observations from satellite altimetry and tide
gauges and causes, by A. Cazenave, CNES, France
Speech
3: Advances in Ocean Dynamics from Satellite Altimetry,
L.L. Fu, NASA/JPL, USA
On
September 11-13, 8 scientific Sessions were held, including G1 (chaired by C
Zhao), G2 (W Bosch), G3 (EL Mathers), GO1 (H Schuh), GO2 (J Klokocnik), GO3 (C
Hwang), O1 (C Zuffada) and O2 (HZ Xu). A total of 37 papers were presented.
A
proceedings volume, which will be included in the IAG symposium series and
published by Springer-Verlag, will be due out in the summer of 2003. This
volume contains 30 peer-reviewed papers conforming to the standard of Journal
of Geodesy.
Summary,
recommendation and future work
The
international altimetry workshop held in China, 2002, highlighted the
activities of SSG3.186. The five lectures delivered in this workshop cover a
wide range of applications and disciplines and also provide basic tools for the
attendees. The papers presented in the scientific sessions cover a large
portion of the proposed subjects of study in SSG 3.186. Overall speaking,
despite reported progress in data processing and theory, improvement in the
proposed subject areas is still needed. Detailed of the works carried by out
the members can be found in the publications listed in Section 5 below.
One focus
of SSG3.186 is on shallow-water altimetry for gravity and geoid computations,
for which new algorithm for data filtering and outlier detections have been
presented. In particular, a new altimetry data type, called differenced was
used. If it is not sea surface height, geoid gradient or differenced height,
what will be a better altimeter data type for marine gravity and geoid
determinations? It was shown that
use of retracked altimetry can improve the accuracy of predicted marine gravity
and geoid. Currently, only retracked ERS is used for marine geoid and gravity
determinations. It will still yet to use more retracked altimetry such as those
from Geosat/GM will contribute to the prediction accuracy. The application of
retracked altimetry data can be also extended to tidal prediction and SST
determination for oceanography.
Many
members and his colleagues have devoted time to tackling the problem of
bathymetric prediction from altimetry data. Two methodologies, one
stochastically based and the other FFT-based, have been used. However, from
their improved results, it seems there is room for gaining more prediction accuracy
in terms of theory and data processing technique. What is the best conversion
theory and procedure for deriving bathymetry from gravity or geoidal height?
Members in this SSG need to have a deeper understanding of geophysics in this
problem before a better method is devised.
Members in
this SSG study SST recovery from satellite altimetry and application to
oceanography mainly over deep oceans. Compared to shipborne methods,
significant results have been achieved, e.g., Hwang and Chen (2000a), Hwang and
Chen (2000b), and Hwang and Kao (2002). However, SST studies over shallow
waters were not carried out among the SSG members. It is not clear whether SST
can be used for deriving geostrophic currents over shallow waters because of
the complex ocean dynamics here. It is indeed very desired to see if coastal
oceanography can benefit from satellite altimetry.
Another
challenge is the combination of data from multi-sensors, such as
satellite/air-borne altimeters, ship/air-borne gravimeters, for marine
geoid/gravity determination.
Different sensors have different noise levels and spatial resolutions,
which make the combination a difficult task.
Many groups
have computed global sets of marine gravity and mean SSH, so it will be
necessary to perform an inter-comparison of these results and compute an
optimal set from these various sets using a weighted average method, something
like the method for combing the IGS orbit of GPS. SSG3.186 may then presents
this optimal set of marine gravity and mean SSH to the world scientific
community for various applications.
Publications of members related to SSG3.186 over 1999-2003
Andersen,
O. and Knudsen, P., The role of satellite altimetry in gravity field modelling
in coastal areas, Phys. Chem. Earth, 25, 17-24, Pergammon, Berlin, 2000.
Andersen,
O.B., and P. Knudsen, The role of satellite altimetry in gravity field modeling
in coastal areas, Phys. Chem. Earth, 25 (10), 17-24, 2000.
Andersen,
O.B., P. Knudsen and R. Trimmer, The KMS99 global gravity field from ERS and
Geosat altimetry, Proc. ERS-Envisat Symp. 2000, Göteborg, Sweden. 2000.
Andritsanos VD, Vergos GS, Tziavos IN, Pavlis EC and
Mertikas SP. A High Reososution Geoid for the Establishment of the Gavdos
Mulit-Satellite Calibration Site. International Association of Geodesy
Symposia, Vol. 123 Sideris (ed.), Gravity Geoid and Geodynamics 2000, Springer
- Verlag Berlin Heidelberg, pp. 347-354, 2001.
Andritsanos,
V.D., and I.N. Tziavos, Estimation of gravity field parameters by a multiple input/output
system. Phys. Chem. Earth (A), 25 (1), 39-46, 2000.
Andritsanos VD, Vergos GS, Tziavos IN and Pavlis EC, Alternative Geoid Solutions in the
Southern Aegean Sea: Comparisons and Results. Presented in the EGS Millennium
General Assembly, April 25-29,Nice, France, 2000.
Anzenhofer,
M., A. Braun, M. Rentsch, C. Reigber, and C. Shum, Coastal Altimetry and
Application, EGS, The Hague, Netherlands, April 1999.
Anzenhofer,
M., C. Shum, and M. Renstch, Coastal altimetry and applications, Ohio State University
Geodetic Science and Surveying Report #464, 2000.
Braun, A.,
S. Eickschen, A. Helm, M. Rentsch, T. Schöne: The ENVISAT RA-2 Value-Added
Ocean/Ice Processor at GFZ Potsdam, ESA - ERS/ENVISAT Symposium, Gothenburg,
Sweden, Oct 2000, Abstract volume.
Deng, X.
and W. Featherstone, Analysis of ERS-2 satellite altimeter waveform data around
Australian coasts, paper presented to the Annual Research Seminar, The
University of New South Wales, Sydney, Australia, 20-21 November, 2000.
Deng, X.,
Featherstone, W.E., Hwang, C. and Shum, C.K, Improved Coastal Marine Gravity
Anomalies at the Taiwan Strait from Altimeter Waveform Retracking, Proceedings
of International Workshop on Satellite Altimetry for Geodesy, Geophysics and
Oceanography: Summer Lecture Series and Scientific Applications, Wuhan, China,
September, 2002.
Deng,
X., Featherstone, W.E., Hwang, C. and Berry, P.A.M. Retracking ERS-2 Radar Altimeter Waveform Data in Australia's
Coastal Zone, Proceedings of IAG 2001 Scientific Assembly, Budapest, Hungary,
September, 2001.
Deng,
X. and Featherstone, W.E., Analysis of ERS-2 Satellite Radar Altimeter Waveform
Data around Australian Coasts, oral paper presented to the University of New
South Wales Annual Research Seminar, Sydney, Australia, November [abstract in:
Geomatics Research Australia, No.73], 2001.
Deng, X.
and Featherstone, W.E, Improved Determination of Sea Surface Heights Close to
the Australian Coast from ERS-2 Satellite Radar Altimetry, oral paper presented
to the XXIII General Assembly of the International Union of Geodesy and
Geophysics (IUGG2003), Sapporo, Japan, July, 2003.
Deng,
X., Featherstone, W.E., Hwang, C. and Berry, P.A.M., Estimation of
Contamination of ERS-2 and POSEIDON Satellite Radar Altimetry Close to the
Coasts of Australia, Marine Geodesy, Vol. 25, No. 4, pp. 249-271, 2002.
Deng,
X., Featherstone, W.E., Hwang, C. and Berry, P.A.M, Analysis of Poseidon and
ERS-2 Satellite Radar Altimeter Waveform Data around Australian Coasts, in:
Schwarz, K.P. and Adam, J. (eds), Vistas for Geodesy in the New Millennium,
Springer, Berlin, pp. 543-550,2002.
Deng, X.,
W. Featherstone, C. Hwang, and C. Shum, Improved coastal marine gravity
anomalies at the Taiwan Strait from altimeter waveform retracking, Wuhan
Altimeter Workshop, Springer-Verlage Berlin Heidelberg, submitted 2003.
Esselborn,
S., und C. Eden: Sea Surface Height changes in the North Atlantic Ocean Related
to the North Atlantic Oscillation, Geophys. Res. Letters, 28, 3473-3476, 2001.
Grebenitcharsky RS, Vergos GS and Sideris MG, Combination of gravity, altimetry and GPS/Leveling
data for the numerical solution of altimetry-gravimetry boundary value
problems. International Association of Geodesy Symposia, Vol. 125 J. Ádám and K.-P. Schwarz
(eds.), Vistas for Geodesy in the New Millennium, Springer ˇV Verlag Berlin
Heidelberg, pp. 150-155, 2002.
Helm, A.,
A. Braun, S. Eickschen and T. Schoene. "Calibration of the Shuttle Radar
Topography Mission X-SAR Instrument Using a Synthetic Altimetry Data
Model", Canadian Journal of Remote Sensing, Volume 28, Number 4, August
2002, 573-580, 2002.
Hwang, C,
and S.-A. Chen, Circulations and eddies over the South China Sea derived from TOPEX/Poseidon
altimetry, J. Geophys. Res.,105, 23,943-23,965, 2000a.
Hwang, C.,
and S.-A Chen, Fourier and wavelet analyses of TOPEX/Poseidon-derived sea level
anomaly over the South China Sea: A contribution to the South China Sea Monsoon
Experiment, J. Geophys. Res., 105, 28,785-28,804. 2000b.
Hwang, C,
and H.-Y. Hsu, 2001. A global mean sea surface grid from Seasat, Geosat, ERS-1,
and TOPEX/POSEIDON altimetry: application of deflection-geoid formula, IAG
Scientific Assembly, Budapest, 2-9 September, 2001.
Hwang, C.,
HY Hsu and RJ Jang, Global mean
sea surface and marine gravity anomaly from multi-satellite altimetry:
applications of deflection-geoid and inverse Vening Meinesz formula J. Geod., Vol.
76, pp. 407-418, 2002.
Hwang, C.
and R. Kao. TOPEX/POSEIDON-derived
space-time variations of Kuroshio Current: applications of a gravimetric geoid
and wavelet
analysis, Geophys. J. Int., 151, 835-847, 2002.
Hwang, C.,
R. Kao, and C-R. Wu, TOPEX/POSEIDON observations of eddies in the Subtropical
Counter Current area: kinematic characteristics of anticyclonic and cyclonic
eddies, paper submitted to J. of Geophys. Res., 2002.
Hwang, C., Hsu, H.Y. and Deng, X., Marine Gravity Anomaly from Satellite Altimetry: A
Comparison of Methods over Shallow Waters, Proceedings
of International Workshop on Satellite Altimetry for Geodesy, Geophysics and
Oceanography: Summer Lecture Series and Scientific Applications, Wuhan, China, September, 2002.
Klokocnik
J, Wagner CA, Combinations of Satellite Crossovers to Study Orbit and
Residual Errors in Altimetry, Celest. Mech. 74: 231-242. 1999.
Klokonick,
J., C.A. Wagner and J. Kostelecky, Residual errors in altimetry data detected
by combinations of single- and dual-satellite crossovers, J. Geod., 73,
671-683, 2000.
Klokocnik
J, Wagner CA, Kostelecky J 2000: Residual Errors in Altimetry Data Detected by
Combinations of Single- and Dual-Satellite Crossovers, J. Geod. 73: 671-683,
2000.
Klokocnik
J, Reigber Ch, Schwintzer P, Wagner CA, Kostelecky J, Evaluation of pre-CHAMP
Gravity Models GRIM5-S1 and GRIM5-C1 with Satellite Crossover Altimetry,
GFZ Sci. Techn. Rep. STR 00/22, Potsdam, J. Geod. 2002, 76: 189-198, 2000.
Medvedev,
P., The use of the satellite altimetry data for Sea of Okhotsk and Caspian Sea
studies and the plans of GPS and GLONASS applications, IAG Scientific Assembly,
Budapest, Sep 2-9, 2001.
Rentsch,
M., A. Braun, T. Schöne, T.
Gruber, and P. Schwintzer, Recent results and applications from GFZ marine
gravity grids, EGS XXV General Assembly, Nice, France, 26 April, 2000.
Rentsch,
M., A. Braun, A. Helm, T. Schöne: Operational Altimetry at GFZ- From ERS-2 to
Envisat. ESA - ERS/ENVISAT Symposium, Gothenburg, Sweden, October 2000.,
Abstract volume.
Schöne,
T., S. Eickschen: Wind Speed and SWH Calibration for Radar Altimetry in the
North Sea, ESA - ERS/ENVISAT Symposium, Gothenburg, Sweden, October, 2000,
Abstract volume.
Schöne,
T., M. Forberg, R. Galas, C. Reigber: GPS-buoys for lifetime RA drift
monitoring, AGU Fall Meeting 2002, EOS Trans. AGU, 83(47), Fall Meet. Suppl.,
Abstract OS52A-0189, 2002.
Shum, C.,
Y. Yi, C. Zhao, T. Urban, B. Berwin, R. Benada, and V. Zlotnicki, Improved
ERS-1 mission radar altimeter geophysical data record data product (DVD-ROM),
JPL/PODAAC, March 2000.
Shum, C.
Global gravity field modeling: geophysical applications, Invited lecture at the
Crustal Deformation Laboratory, Geography and Crustal Dynamics Research Center,
Geographical Survey Institute, Tsukuba, Japan, February 28, 2001.
Shum, C.,
Altimeter methods for satellite geodesy, Keynote speaker, International
Workshop on Satellite altimetry for Geodesy, Lecture 1: Principles of satellite
altimetry and application to sea level change studies, Wuhan, China, September
8-13, 2002.
Tocho C, Vergos GS, Sideris MG, Optimal Marine Geoid
Determination In The Atlantic Coastal Region Of Argentina. Presented at the
2003 General Assembly of the International Union of Geodesy and Geophysics
(IUGG2003), June 30 ˇV July 11, Sapporo, Japan, 2003.
Tziavos IN, Vergos GS and the GAVDOS Team, A Survey of
Marine Geoid Estimation Using Satellite and Shipborne Data in Gavdos. Presented
at the XXVII EGS General Assembly, April 21-26, Nice, France, 2002a.
Tziavos IN, Vergos GS and the GAVDOS Team, A Survey of Marine Geoid Estimation
Using Satelite and Shipborne Data in Gavdos II. Presented at the 3rd Meeting of
the International Gravity and Geoid Commission (IGGC), Gravity and Geoid 2002 -
GG2002, August 26-30, Thessaloniki, Greece, 2002b.
Urban, T.,
J. Ries, B. Tapley, and C. Shum, The integration of twenty-five years of
sea-level measurements from satellite altimetry, IUGG Symposia, JSG11,
Birmingham, UK, July, 1999.
Vergos,
G.S., and M.G. Sideris, Improving the estimation of bottom ocean topography
with satellite altimetry derived gravity data using the integrated inverse
method, IAG Scientific Assembly,
Budapest, 2-9 September, 2001.
Vergos GS, Bayoud FA, Sideris MG and Tziavos IN,
High-Resolution Geoid Computation by Combining shipborne and Multi-Satellite
altimetry Data in the Eastern Mediterranean Sea. IGeS Buletin Special Issue,
Vol. 13, Proceedings of the EGS 2001 - G7 Session "Regional and Local
Gravity Field Approximation", I.N. Tziavos and R. Barzaghi (eds.), pp.
85-99, March 25-30, Nice, France, 2002.
Vergos GS, Grebenicharsky RS and Sideris MG, Combination
of Multi-Satellite Altimetry and Shipborne Gravity Data for Geoid Determination
in a Coastal Region of Eastern Canada. IGeS Buletin Special Issue, Vol.
13, Proceedings of the EGS 2001 - G7 Session "Regional and Local Gravity
Field Approximation", I.N. Tziavos and R. Barzaghi (eds.), pp. 100-115,
March 25-30, Nice, France, 2002.
Vergos GS, Sideris MG, Improving the Estimation of Bottom Ocean Topography with
Altimetry-Derived Gravity Data Using the Integrated Inverse Method.
International Association of Geodesy Symposia, Vol. 125,J.
Ádám and K.-P. Schwarz (eds.), Vistas for
Geodesy in the New Millennium, Springer ˇV Verlag Berlin Heidelberg, pp.
529-534, 2001.
Vergos GS and Sideris MG, Estimation of High-Precision
Marine Geoid Models Offshore Newfoundland, Eastern Canada. 3rd Meeting of the
International Gravity and Geoid Commission (IGGC), Tziavos (ed.), Gravity and
Geoid 2002 - GG2002, pp. 126-131, 2003a.
Vergos GS and Sideris MG, Altimetry-Derived Marine Gravity Field Estimation Using
Single- and Multi-Satellite Data. 3rd Meeting of the International Gravity and
Geoid Commission (IGGC), Tziavos (ed.), Gravity and Geoid 2002 - GG2002, pp.
308-313, 2003b.
Vergos GS,
Grebenicharsky RS and Sideris MG, Sea Surface Topography and Geostrophic Flow
Estiamtion from Multi-Satellite Altimetry and Shipborne Gravity Data Using
Wavelet Decomposition. 3rd Meeting of the International Gravity and Geoid
Commission (IGGC), Tziavos (ed.), Gravity and Geoid 2002 - GG2002, 314-319,
2003.
Vergos GS, Andritsanos VD, Tziavos IN, On the
Determination of Marine Geoid Models by Least-Squares Collocation and Spectral
Methods Using Heterogeneous Data. Presented at the 2003 General Assembly of the
International Union of Geodesy and Geophysics (IUGG2003), June 30 ˇV July 11,
Sapporo, Japan, 2003.
Vergos GS, Grebenicharsky RS and Sideris MG, Improving
the Marine Geoid by Combining Satellite and Shipborne Data. Presented at the
3rd Annual Conference of the GEOIDe Network of Centers of Excellence (NCE),
June 21 ˇV 22, 2001, Fredericton, New Brunswick, Canada, 2001.
Vergos GS, Sideris MG, On Improving the Determination of the Gravity Field by
Estimating the Bottom Ocean Topography with Satellite Altimetry and Shipborne
Gravity Data. Presented at the Joint IAPSO/IABO Oceanographic Meeting, Mar del
Plata, Argentina, October 21-28, 2001.
Vergos GS and Sideris MG, Bottom Ocean Topography
Estimation Improvement Using Altimetry and Depth Soundings. Presented at the
XXVII EGS General Assembly, April 21-26, Nice, France, 2002a.
Vergos GS and Sideris MG, Marine Geoid
Estimation Using Satellite and Shipborne Data. Presented at the Annual
Scientific Meeting of the Canadian Geophysical Union, May 18-21, Banff, Canada,
2002b.
Vergos GS and Sideris MG, Gravity Field and
Quasi-stationary Sea Surface Topography Estimation Using Heterogeneous Data.
Presented at the Annual Scientific Meeting of the Canadian Geophysical Union,
May 18-21, Banff, Canada. 2002c.
Vergos GS, Sideris MG, Tziavos IN, High-Resolution and High-Accuracy Marine
Geoid Estimation in the Aegean Sea Using Satellite and Shipborne Data.
Presented at the 3rd Meeting of the International Gravity and Geoid Commission
(IGGC), Gravity and Geoid 2002 - GG2002, August 26-30, Thessaloniki, Greece,
2002.
Wagner CA,
Klokocnik J, Kostelecky , Improvement of Geopotential and Detection of
Interannual Oceanographic Signals from Inversion ofSingle and Dual Satellite
Altimetry, VUGTK Prague-Zdiby, ser. Vol. 46, # 26, 39 pages, 2000.
Wang, Y.,
The satellite altimeter data derived mean sea surface GSFC98, Geophys. Res.
Lett., 27 (5), 701-704, 2000.
Yi, Y., C.
Shum, H. Tseng, M. Anzenhofer, M. Rentsch, and C. Hwang. On the advances of
marine gravity anomaly models determined from GEOSAT, ERS-1 and TOPEX/POSEIDON
satellite radar altimetry, IUGG Symposia, G3, Birmingham, UK, July, 1999.
Yi, Y., A.
Braun, K. Cheng, C. Shum, and S. Calmant, Initial ENVISAT RA-2 Cal/Val results,
ENVISAT RA-MWR CCVT Fourth Plenary Meeting, ESA/ESRIN, Frascati, Italy, 3-4
December 2002.
Yi, Y., A.
Braun, C. Shum, K. Cheng and S. Calment, Envisat RA2 cal/val results, Envisat
RA-2/MWR CCVT Sixth Plenary Meeting, ESA/ESRIN, Frascati, Italy, March 25-27,
2003.
Yi, Y., K.
Cheng, C. Shum, A. Braun, and S. Calmant, ENVISAT RA-2 calibration/validation,
Proc. EGS-AGU-EUG Joint Assembly, Nice, France, April 6-11, 2003.
Zhao. C.,
C. Shum, Y. Yi, P. Luk, J. Finkelstein, J. Lillibridge, J. McMillan, and M.
Rau, GFO radar altimeter data product verifications and ocean circulation
studies, IAG Scientific Assembly, Vistas for Geodesy in the New Millennium,
Budapest, Hungary, September 2-7, 2001.
Zhao, C.,
C. Shum and Y. Yi, Ionosphere corrections of radar altimeters and calibration
results of GFO, Invited, International Workshop on Satellite altimetry for
Geodesy, Geophysics and Oceanography: Summer Lecture Series and Scientific
Applications, Wuhan, China, September 8-13, 2002.
List of
papers published in the proceedings of international altimetry workshop on
altimetry (available by order to Springer-Verlag in summer 2003)
Denis L.
Volkov and Hendrik M. van Aken, Low frequency change of sea level in the north
atlantic ocean as observed with satellite altimetry
Cinzia
Zuffada, Stephen Lowe, Yi Chao and Robert Treuhaft, Oceanography with GPS.
Zhang
Ruihua, Shi Pan, Peng Fuqing, Xia Zheren and Liu Guangming, Determination of 
marine gravity
anomalies from multisatellite altimetry.
X. Dong, C.
Huang, P. Woodworth,
P. Moore, R. Bingley, Absolute calibration of
the ers-2 altimeter using UK tide gauges.
S.
kahlouche, A. Rami, S.A Benahmed Daho, Topex altimetric mean sea level and
gravimetric geoid in the north of Algeria.
Cho-Teng
Liu, Ching-Hsi Nan, Chung-Ru Ho, Nan-Jung Kuo, Ming-Kuang Hsu, and Ruo-Shan Tseng, Application of satellite remote sensing on the tuna
fishery of eastern tropical Pacific.
Carla
Braitenberg, Elena Pagot, Yong
Wang, and Jian Fang, Bathymetry
and crustal thickness variations from gravity inversion and flexural isostasy.
Lifeng Bao
and Yang Lu, Recovering deflections of vertical from a tangent plane of gridded
geoidal heights from altimetry.
Guoqi Han,
Current Variability over the Scotian Slope in the 1990s.
Jingyng
Bao, Dingbo Chao, Jinping Zhao, Qi Wang and Yanchun Liu, harmonic tidal
analysis along T/P tracks in China Seas and vicinity.
Y. Yang,
C. T. Liu, T. N. Lee, and W. E. Johns, Geostrophic uncertainty and anomalous
current structure in association with mesoscale eddies delineated by altimeter
observations east of Taiwan.
Ole B. Andersen, The M4 Shallow water
tidal constituent from altimetry and tide gauges.
Gao
Jinyao, and Jin Xianglong, Joint application of altimeter
data and
egm96 to submarine
tectonic and geodynamic study in west pacific.
Jianguo
Hu, Zhengtao Wang, Jiancheng Li, and Dingbo
Chao, Sea level changes
detected by using satellite
altimeter data and comparing with
tide gauge records in China Sea.
Yang Lu,
and Hou-Tse Hsu, Pseudo-harmonic representation of gravity field over South
China Sea.
Jiang
Weiping Li Jiancheng,
Wang Zhengtao, Determination of global mean sea
surface using multi-satellite altimetric data.
Huang
Motao, Zhai Guojun, Bian Shaofeng, Ouyang Yongzhong,Liu Yanchun, and Liu
Chuanyong, Comparisons of three inversion approaches for recovering gravity anomalies
from altimeter data.
C Hwang, R
Kao and CR Wu, The kinematics of mesoscale eddies from TOPEX/POSEIDON altimetry
over the Subtropical Counter Current.
Gustavo
Acuna and Wolfgang Bosch, Absolute comparison of satellite altimeter
observations and tide gauge registrations in Venezuela.
J.
Benveniste, M.P. Milagro-Perez, M. Roca and G. Levrini, The Envisat Ra-2 radar altimeter
system.
C Hwang,
HY Hsu, Marine gravity anomaly from satellite altimetry: a comparison of
methods over shallow waters.
Jeong Woo
Kim, Daniel Roman and Ralph R.B. von Frese, Enhanced Free-air Gravity Anomalies
by Satellite Radar Altimetry.
Lucy
Mathers, An intercomparison of parametric models of sea state bias for the
TOPEX, Poseidon and Jason altimeters.
Sergey A. Lebedev, Oleg I.
Zilberstein, Sergey K.
Popov and Olga V.
Tikhonova, Analysis of temporal sea
level variation of the Barents and the White seas by satellite altimetry data,
results of hydrodynamic simulation and tide gauge data.
J. Klokočník, C.A. Wagner
and J. Kostelecký, Accuracy
assessment of the earth gravity field models by means of independent satellite
crossover altimetry,
Chen
Lu-Ying and Xu Hou-ze, Determination of sea level height variation by dynamics
crossovers adjustment.
Schuh, H. , G. Estermann, J.-F. Crétaux , and T. van
Dam, Investigation of hydrological and atmospheric loading by
space geodetic techniques.
Changyin
Zhao, C. K. Shum and Yuchan Yi, Calibration results of GFO.
C.K. Shum,
Yuchan Yi, Ole Andersen and Per Knudsen, Extreme southern ocean tide modeling
using radar altimeters