Difference between pages "IC SG3" and "IC SG5"

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<big>'''Configuration analysis of Earth oriented space techniques'''</big>
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<big>'''JSG 0.5: Multi-sensor combination for the separation of integral
 +
geodetic signals'''</big>
  
 
Chair: ''F. Seitz (Germany)''<br>
 
Chair: ''F. Seitz (Germany)''<br>
Affiliation: ''Comm. 3, 2, 1''
+
Affiliation: ''Comm. 2, 3 and GGOS''
  
 
__TOC__
 
__TOC__
===Introduction===
+
===Objectives===
 +
 
 +
A large part of the geodetic parameters derived from space geodetic observation techniques are integral quantities of the Earth system. Among the most prominent ones are parameters related to Earth rotation and the gravity field. Variations of those parameters reflect the superposed effect of a multitude of dynamical processes and interactions in various subsystems of the Earth. The integral geodetic quantities provide fundamental and unique information for different balances in the Earth system, in particular for the balances of mass and angular momentum that are directly related to (variations of) the gravity field and Earth rotation. In respective balance equations the geodetic parameters describe the integral effect of exchange processes of mass and angular momentum in the Earth system. In contrast to many other disciplines of geosciences, geodesy is characterized by a very long observation history. Partly, the previously mentioned parameters have been determined over many decades with continuously improved space observation techniques. Thus geodesy provides an excellent data base for the analysis of long term changes in the Earth system and contributes fundamentally to an improved understanding of large-scale processes.
 +
 
 +
However, in general the integral parameter time series cannot be separated into contributions of specific processes without further information. Their separation and therewith their geophysical interpretation requires complementary data from observation techniques that are unequally sensitive for individual effects and/or from numerical models. Activities of the study group are focussed on the development of strategies for the separation of the integral geodetic signals on the basis of modern space-based Earth observation systems. A multitude of simultaneously operating satellite systems with different objectives is available today. They offer a broad spectrum of information on global and regional-scale processes at different temporal resolutions. Within the study group it shall be investigated in which way the combination of heterogeneous data sets allows for the quantification of individual contributors to the balances of mass and angular momentum.
  
Activities of the study group are focussed on modern methods of Earth observation from space. Today a multitude of simultaneously operating satellite systems with different objectives are available. They offer a broad spectrum of information on global and regional-scale processes within and/or between individual components of the Earth system in different temporal resolutions.
+
The research activities shall be coordinated between the participating scientists and shall be conducted in interdisciplinary collaboration. At all times the group is open for new contacts and members in order to embed the activities in a wide context. The study group is primarily affiliated with the IAG commissions 2 (Gravity field) and 3 (Earth rotation and geodynamics).
  
The general objective of this study group is the development of strategies how complementary and redundant information from heterogeneous observation types can be combined and analysed with respect to physical processes in the Earth system.
+
===Objectives===
  
Most of the measurement techniques are restricted to the observation of integral effects of a multitude of underlying geophysical processes. It shall be investigated in which way the combination of heterogeneous data sets allows for the separation of processes and the identification of individual contributors.
+
The primary objective of the study group is the development of strategies for multi-sensor combinations with the aim of separating time series of integral geodetic parameters related to Earth rotation and gravity field. The separation of the parameter time series into contributions of individual underlying effects fosters the understanding of dynamical processes and interactions in the Earth system. This is of particular interest in the view of global change.
  
In particular the studies span geometrical observation techniques (e.g. point positioning systems, imaging radar systems), gravimetrical observation techniques (e.g. GRACE, GOCE) and sensors which allow for the direct observation of individual physical processes (e.g., IceSat, SMOS).
+
Individual contributions from various subsystems of the Earth shall be quantified and balanced. In particular our investigations focus on the separation of the Earth rotation parameters (polar motion and variations of length-of-day) into contributions of atmospheric and hydrospheric angular momentum variations, and on the separation of GRACE gravity field observations over continents into the contributions of individual hydrological storage compartments, such as groundwater, surface water, soil moisture and snow.
 +
Investigations in the frame of the study group will exploit the synergies of various observation systems (satellite altimetry, optical and radar remote sensing, SMOS, and others) for the separation of the signals and combine their output with numerical models. Among the most important steps are compilation and assessment of background information for individual observation systems and sensors (mode of operation, sensitivity, accuracy, deficiencies) as well as theoretical studies which (new) information on the Earth system can be gained from a combination of different observation methods.
  
The combination of complementary and redundant observation types fosters and improves the understanding of the Earth system. This implies more reliable information on processes and interactions in the subsystems of the Earth which is especially necessary with regard to studies of global change.
+
In particular the research comprises the following topics:
 +
* potential und usability of contemporary spaceborne and terrestrial sensors for an improved understanding of processes within atmosphere and hydrosphere,
 +
* analysis of accuracy, temporal and spatial resolution and coverage of different data sets,
 +
* theoretical and numerical studies on the combination of heterogeneous observation types; this comprehends investigations on appropriate methods for parameter estimation including error propagation, the analysis of linear dependencies between parameters and the solution of rank deficiency problems,
 +
* mathematical methods for the enhancement of the information content (e.g., filters),
 +
* quantification of variations of mass and angular momentum in different subsystems from multi-sensor analysis,
 +
* analysis of the consistencies of balances between individual effects and integral geodetic parameters on different spatial scales,
 +
* formulation of recommendations for future research and (if possible) for future satellite missions on the basis of balance inconsistencies.
  
Among the most important steps are compilation and assessment of background information for individual systems and sensors (mode of operation, sensitivity, accuracy, deficiencies) as well as theoretical studies which (new) information on the Earth system can be gained from a combination of different observation methods.
+
===Planned Activities===
  
===Objectives===
+
* Set-up of a JSG webpage for dissemination of information (activities and a bibliographic list of references) and for presentation and communication of research results.
 +
* Organization of conference sessions / workshops:
 +
** planned in 2013: Conference Session in the Hotine Marussi Symposium
 +
** planned in 2014: 2nd workshop on the Quality of Geodetic Observing and Monitoring Systems (QuGOMS’ 14)
 +
* Common publications of SG members
 +
* Common fund raising activities (e.g., for PhD. positions)
 +
 
 +
===Principal Scientific Outcome/Results===
 +
 
 +
By the end of the 4-year period 2011-2015 the following outcome shall be achieved:
 +
Mature experience in geodetic multi-sensor data combina-tion including data availability, formats, combination strategies and accuracy aspects.
 +
Numerical results for separated hydrological contributions to integral mass variations observed by GRACE for selected study areas.
 +
Numerical results for separated atmospheric/hydrospheric contributions Earth rotation parameters on seasonal to inter-annual time scales.
 +
Initiation of at least one common funded project with positions for PhD students working in the topical field of the study group.
  
* which processes in the Earth system are insufficiently known and which parameters are imprecisely determined?
+
===Members===
* can the understanding of individual processes be improved by common analysis of different observations types?
 
* which are the target parameters and how are the connections with other variables?
 
* which sensors are available and sensitive for the target parameters?
 
* which sensors can be used to reduce unwanted signals?
 
* which are the accuracies, temporal and spatial resolutions of the different data sets and which regions and time spans are covered?
 
* are the data publicly available or is their access restricted?
 
* which pre-processing steps are neccessary in order to extract the proper information from the raw observtion data?
 
* have the data already been pre-processed? Which methods, models and conventions have been applied? Are there possible error sources or inconsistencies?
 
* which methods can be applied in order to enhance the information content (e.g. filters)?
 
* how can the heterogeneous observation types can be combined expediently?
 
* how do the observation equations look like?
 
* which methods for parameter estimation can be applied? How can linear dependencies between parameters and rank deficiency problems be solved?
 
* how can balance equations be regarded in the combination process (e.g. mass and energy balance)?
 
* are ther additional information (models and terrestrial data) which can/must be considered?
 
* which of the desired parameters can be assessed with the available observation techniques?
 
* which further parameters are desired and how could appropriate missions for the future look like?
 
  
The research activities shall be coordinated between the participating scientists and shall be conducted in interdisciplinary collaboration. At all times the group is open for new contacts and members in order to embed the activities in a wide context.
+
'' '''Florian Seitz (Germany), chair''' <br /> Sarah Abelen (Germany) <br /> Rodrigo Abarca del Rio (Chile) <br /> Andreas Güntner (Germany) <br /> Karin Hedman (Germany) <br /> Franz Meyer (USA) <br /> Michael Schmidt (Germany) <br /> Manuela Seitz (Germany) <br /> Alka Singh (India) <br />''

Revision as of 10:49, 2 July 2012

JSG 0.5: Multi-sensor combination for the separation of integral geodetic signals

Chair: F. Seitz (Germany)
Affiliation: Comm. 2, 3 and GGOS

Objectives

A large part of the geodetic parameters derived from space geodetic observation techniques are integral quantities of the Earth system. Among the most prominent ones are parameters related to Earth rotation and the gravity field. Variations of those parameters reflect the superposed effect of a multitude of dynamical processes and interactions in various subsystems of the Earth. The integral geodetic quantities provide fundamental and unique information for different balances in the Earth system, in particular for the balances of mass and angular momentum that are directly related to (variations of) the gravity field and Earth rotation. In respective balance equations the geodetic parameters describe the integral effect of exchange processes of mass and angular momentum in the Earth system. In contrast to many other disciplines of geosciences, geodesy is characterized by a very long observation history. Partly, the previously mentioned parameters have been determined over many decades with continuously improved space observation techniques. Thus geodesy provides an excellent data base for the analysis of long term changes in the Earth system and contributes fundamentally to an improved understanding of large-scale processes.

However, in general the integral parameter time series cannot be separated into contributions of specific processes without further information. Their separation and therewith their geophysical interpretation requires complementary data from observation techniques that are unequally sensitive for individual effects and/or from numerical models. Activities of the study group are focussed on the development of strategies for the separation of the integral geodetic signals on the basis of modern space-based Earth observation systems. A multitude of simultaneously operating satellite systems with different objectives is available today. They offer a broad spectrum of information on global and regional-scale processes at different temporal resolutions. Within the study group it shall be investigated in which way the combination of heterogeneous data sets allows for the quantification of individual contributors to the balances of mass and angular momentum.

The research activities shall be coordinated between the participating scientists and shall be conducted in interdisciplinary collaboration. At all times the group is open for new contacts and members in order to embed the activities in a wide context. The study group is primarily affiliated with the IAG commissions 2 (Gravity field) and 3 (Earth rotation and geodynamics).

Objectives

The primary objective of the study group is the development of strategies for multi-sensor combinations with the aim of separating time series of integral geodetic parameters related to Earth rotation and gravity field. The separation of the parameter time series into contributions of individual underlying effects fosters the understanding of dynamical processes and interactions in the Earth system. This is of particular interest in the view of global change.

Individual contributions from various subsystems of the Earth shall be quantified and balanced. In particular our investigations focus on the separation of the Earth rotation parameters (polar motion and variations of length-of-day) into contributions of atmospheric and hydrospheric angular momentum variations, and on the separation of GRACE gravity field observations over continents into the contributions of individual hydrological storage compartments, such as groundwater, surface water, soil moisture and snow. Investigations in the frame of the study group will exploit the synergies of various observation systems (satellite altimetry, optical and radar remote sensing, SMOS, and others) for the separation of the signals and combine their output with numerical models. Among the most important steps are compilation and assessment of background information for individual observation systems and sensors (mode of operation, sensitivity, accuracy, deficiencies) as well as theoretical studies which (new) information on the Earth system can be gained from a combination of different observation methods.

In particular the research comprises the following topics:

  • potential und usability of contemporary spaceborne and terrestrial sensors for an improved understanding of processes within atmosphere and hydrosphere,
  • analysis of accuracy, temporal and spatial resolution and coverage of different data sets,
  • theoretical and numerical studies on the combination of heterogeneous observation types; this comprehends investigations on appropriate methods for parameter estimation including error propagation, the analysis of linear dependencies between parameters and the solution of rank deficiency problems,
  • mathematical methods for the enhancement of the information content (e.g., filters),
  • quantification of variations of mass and angular momentum in different subsystems from multi-sensor analysis,
  • analysis of the consistencies of balances between individual effects and integral geodetic parameters on different spatial scales,
  • formulation of recommendations for future research and (if possible) for future satellite missions on the basis of balance inconsistencies.

Planned Activities

  • Set-up of a JSG webpage for dissemination of information (activities and a bibliographic list of references) and for presentation and communication of research results.
  • Organization of conference sessions / workshops:
    • planned in 2013: Conference Session in the Hotine Marussi Symposium
    • planned in 2014: 2nd workshop on the Quality of Geodetic Observing and Monitoring Systems (QuGOMS’ 14)
  • Common publications of SG members
  • Common fund raising activities (e.g., for PhD. positions)

Principal Scientific Outcome/Results

By the end of the 4-year period 2011-2015 the following outcome shall be achieved: Mature experience in geodetic multi-sensor data combina-tion including data availability, formats, combination strategies and accuracy aspects. Numerical results for separated hydrological contributions to integral mass variations observed by GRACE for selected study areas. Numerical results for separated atmospheric/hydrospheric contributions Earth rotation parameters on seasonal to inter-annual time scales. Initiation of at least one common funded project with positions for PhD students working in the topical field of the study group.

Members

Florian Seitz (Germany), chair
Sarah Abelen (Germany)
Rodrigo Abarca del Rio (Chile)
Andreas Güntner (Germany)
Karin Hedman (Germany)
Franz Meyer (USA)
Michael Schmidt (Germany)
Manuela Seitz (Germany)
Alka Singh (India)