| Reference Frame in Practice Technical Seminar 
				4-5 May 2012 Rome Italy The IAG, (International Association of Geodesy), FIG and ICG 
	(International Committee on GNSS) held a technical seminar prior to the 
	Working Week, on 4-5 May 2012. This event was held at the Cassa Geometri 
	(Cassa Italiana Di Previdenza Ed Assistenza Dei Geometri Liberi 
	Professionisti). 42 delegates were present on both days to listen and 
	discuss presentations on -  
					The Role of Geodesy–GGOS and Future Trends by Prof. Chris Rizos 
		President IAG – This presentation provided an overview of the transition 
		from traditional to modern geodesy, describing the evolution of roles, 
		impact of services, central importance of reference frame definition, 
		contributions to geoscience and GGOS. 
Global Terrestrial Reference Systems and Frames by Dr Zuheir 
		Altamimi, who discussed theory relating to ITRS / ITRF / WGS-84; 
		associated transformations; how ITRF is determined; and how geodetic 
		techniques (VLBI, GNSS, DORIS, SLR) contribute to ITRF. 
Regional and National reference systems by Eng. Joao Torres and Dr 
		John Dawson. This session described the mathematical relationship 
		between the ITRF and regional or national reference frames using EUREF 
		and APREF as case studies. The topics covered included the definition, 
		realisations, GNSS CORS infrastructure and campaigns, transformations, 
		and monitoring of such regional reference frames. 
Worked examples of Terrestrial Reference Frame Realisations by Dr 
		John Dawson, Prof Volker Schwieger, and Mr Nic Donnelly. In this session 
		delegates were provided additional case studies from countries 
		describing how their geodetic datum has been realised in relationship to 
		a regional reference frame or ITRF and any local problems and issues. It 
		also included the discussion of issues for an intra-plate country as 
		opposed to one across a plate boundary.  
					IGS Services and Other Initiatives by Ms Ruth Neilan. In this 
		presentation, an overview on how these services and other initiatives 
		contribute to global reference systems; regional and national reference 
		systems; organisational benefits; and how do agencies participate i.e. 
		requirements was provided. 
Gravity and WHS by Dr Dan Roman. In this session, the presenter 
		focused on the relationship between various aspects of the Earth's 
		gravity field such as the geoid, geopotentials, gravity, deflections of 
		the vertical, and physical heights (e.g., above mean sea level). It also 
		covered the different means of observing the gravity field and how they 
		are combined to produce models for height determination both at global 
		scales, such as the World Height System, and locally for National 
		Vertical Datums. 
Multi GNSS Environment by Ms Sharafat Gadimova, Dr Lawrence Lau, and 
		Mr Larry Hothem. The presenters provided an overview of the ICG work 
		plan, its activities, and the Providers Forum. There were also 
		presentations on the’ state of play’ and ‘emerging issues’ relating to a 
		multi GNSS environment. This included information relating to signals, 
		augmentation and space; the technical effects of a multi GNSS 
		environment on reference frame infrastructure, positioning applications 
		and techniques. 
Standards and Traceability of a Terrestrial Reference Frame / GNSS 
		by Dr David Martin and Mr Larry Hothem. This session provided an 
		overview of the standards, best practice and traceability respect to 
		reference frames, GNSS measurements, GUM, the ISO 9000 series of 
		standards, the ISO 17123 series and TC211. It also included the status 
		of Geodetic Network Registry. 
Four dimensional deformation models for Terrestrial Reference Frames 
		by Mr Graeme Blick and Mr Richard Stanaway. The presentations examined 
		the concepts of 4 dimensional datums; the pros and cons of static, 
		semi-dynamic datum and dynamic datums; and the development of 
		Deformation Models which incorporate the effects of events such as 
		earthquakes. The information was explained through case studies from 
		Australia and New Zealand.  The organizers of this seminar would like to thank Cassa Geometri, 
	Trimble Navigation, ESRI and the hosts CNGeGL for their support and 
	assistance to make this event a success. We would also like to thank UNOOSA 
	(United Nations Office for Outer Space Affairs) for their generosity as they 
	sponsored 4 delegates to attend this seminar.  Rob Sarib and Mikael LiljeMay 2012
 06 June 2012 |