on the vision of an international altimeter service (ias) invitation to discuss the ias wolfgang...

On the vision of an

International Altimeter Service (IAS)

Invitation to discuss the IAS

Wolfgang Bosch,

[email protected]

On the vision of an

International Altimeter Service (IAS)

Invitation to discuss the IAS

Wolfgang Bosch,

[email protected]

OST Science Team Meeting, Hobart, March 12-15, 2007 2

Rationale for IAS (top-down)Rationale for IAS (top-down)Rationale for IAS (top-down)Rationale for IAS (top-down)

• Focus on Global Earth Observing Systems (GEOS) to be coordinated by GEOSS, a system of systems

• G4OS:– GOOS for the Ocean– GCOS for Climate– GTOS for the terrestrial Component, and– GGOS for the geodetic component

• Due to its many interdisciplinary applications for oceanography, marine geophysics, the Earth gravity field, the Earth rotation, … satellite altimetry has to be a mandatory element of GEOS


Rationale for IAS (bottom-up)Rationale for IAS (bottom-up)Rationale for IAS (bottom-up)Rationale for IAS (bottom-up)

• There are already (many and excellent) services for satellite altimetry, but in spite of that users are sometimes lost in hyperspace– Differences between MGDR-C (CNES) and MGB

(NASA) known?– Where can users find the most reliable estimate of

range biases of Jason1 or ENVISAT?– Why are all users forced to perform their own

upgrade for new orbits (due to improved gravity fields) and new correction models (tides, SSB, wet tropo)?

– Should a user take KMS04 or CLS01 or DSNC07? – Why are there different formats for the marine

gravity data ( S&S and DNSC)? – Where to get informed about different estimates of

the Mean Dynamic Ocean Topography?


IGS – a model for IAS ?IGS – a model for IAS ?IGS – a model for IAS ?IGS – a model for IAS ?

• Motivation for IAS derived from IGS (International Global Navigation Satellite Systems Service), successfully realised– By voluntary cooperation of many organisations using– Standards for observation (RINEX) and solutions

(SINEX)

• Acknowledge! Without IGS (ILRS, IVS) we would miss– Precise orbits of altimeter satellites– Definition and maintenance of International

Terrestrial Reference Frame (ITRF) – crucial for investigating any long-term evolution of the sea level


Experiences from IGS and other servicesExperiences from IGS and other servicesExperiences from IGS and other servicesExperiences from IGS and other services

• Once a Service is established it gets its own dynamic

• To contribute to a service may help to request external funds

• Existence and impact of services did help to avoid reduction of space techniques


IAS Planning Group (IAS-PG)IAS Planning Group (IAS-PG)IAS Planning Group (IAS-PG)IAS Planning Group (IAS-PG)

• Initiated in 2003 by a Call of C.K. Shum, Ph. Woodworth, G. Mitchum, and W.Bosch

• hosted by IAG, Commission1 „Reference Systems“ == COSPAR Subcommission „Coordination of Space Techniques“

• Official endorsements by – Global Sea Level Observing System GLOSS(IOC)– International Association of Geodesy, IAG– International Association of the Physical Sciences

of the Oceans, IAPSO


IAS-PG ConclusionsIAS-PG ConclusionsIAS-PG ConclusionsIAS-PG Conclusions

• General agreement: an Altimetry Service is useful and should be created

• IAS shall be built upon voluntary contributions and integrate (and extend) existing services

• IAS shall coordinate, leaving processing and data storage at different institutions/centres

• IAS shall provide a single point-of-contact , a „one-stop-shop“ for users

• IAS shall cover the entire spectrum of altimetry applications, including all surface types (ice, lakes, land)


First attempt towards an IASFirst attempt towards an IASFirst attempt towards an IASFirst attempt towards an IAS

• Drafting IAS Terms of References 1) with structure and organisation similar to other services

• IAS splinter in Venice 2006: No consensus on this ToR– organisational overhead (Governing Board) not

accepted– no organisation ready to operate a Central Bureau– IAS objectives too imprecise (what data what

products?)

• New attempt (one step back): – The IAS organisation needs to be reviewed– focus should be on pilot projects demonstrating

value adding to existing services1) http://www.dgfi.badw.de/wiki/Documents/IAS-TOR-06-02-14.doc

http://www.dgfi.badw.de/wiki/Documents/IAS-TOR-06-02-14.doc


Call for an IAS- Integrating Office (IAS-IO)Call for an IAS- Integrating Office (IAS-IO)Call for an IAS- Integrating Office (IAS-IO)Call for an IAS- Integrating Office (IAS-IO)

• Submitted on January, 15, 2007

• seeking proposals for the establishment of an IAS-Integrating Office with the general objectives– to provide a single point of contact for

information on satellite altimetry and its applications;

– to communicate with, and interface to, mission data providers, centres which process, archive, and analyse altimeter data, and other related services/organizations;

– to promote satellite altimetry as a core element of Global Earth Observing Systems


IAS-IO shall accomplish its mission byIAS-IO shall accomplish its mission byIAS-IO shall accomplish its mission byIAS-IO shall accomplish its mission by

• Collaborating with space agencies, processing centres, research institutes, altimeter experts

• Establishing a collaborative Web site (Wiki or Content Management System) (a single point-of-contact)

• Directing user requests to the appropriate organizations (IAS a mediator)

• Establishing pilot projects to enhance and expand its activities (may evolve to permanent components of IAS)

• Reporting to IAG, IAPSO, GLOSS, GEOSS, G4OS and other bodies


The roadmap for IAS-IOThe roadmap for IAS-IOThe roadmap for IAS-IOThe roadmap for IAS-IO

• Proposals will be reviewed by the Nomination Committee (NC, representatives of IAG, IAPSO, GLOSS, related services)

• One of the applicants shall be recommended to take the lead of the IAS-IO

• The NC may suggest a list of intial tasks and value-adding activities of the IAS-IO.


Suggestions for IAS-Pilot projectsSuggestions for IAS-Pilot projectsSuggestions for IAS-Pilot projectsSuggestions for IAS-Pilot projects

• Distributed (on-request) upgrade of GDR data by retracked data, new orbits and/or correction models– Can take advantage of high granularity of GDRs– Decomposition and re-merging of GDRs easy– Sharing distributed resources e.g. by GRID

technology,

• Harmonisation or common user interface for marine gravity data

• New compilation of global ocean tides models. If possible complete this collection by regional tide models and provide uniform interfaces

• Improvements of tides in shallow water (empirically and/or by assimilation into regional models)


IAS in the context of CAGS and ICSUIAS in the context of CAGS and ICSUIAS in the context of CAGS and ICSUIAS in the context of CAGS and ICSU

• At present, services are operating under the umbrella of the Committee on Astronomical and Geophysical Services, CAGS (formerly FAGS)

• Future role of CAGS unclear, to be reviewed in 2 years by the International Council of Scientific Unions, ICSU)

• ICSU Priority Area Assessment (PAA) focuses on Scientific Data and Information (SciDIF). Integration of IGS, ILRS, IVS, IAS, … ?


Possible funding of IAS-IO activitiesPossible funding of IAS-IO activitiesPossible funding of IAS-IO activitiesPossible funding of IAS-IO activities

• U.S. funding situation not known.

• In the European context there are Open Call’s for financing networking, meetings, conferences, and scientific exchange for Earth System Science

• COST action of the European Science Foundation

• Participation of at least five COST member states required

• Clould be CLS, NOC, DNSC, DEOS + German Group.

• Two stage procedure with preliminary/final proposals. Deadline for preliminary proposals is March 30! Interested?