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GENERAL

The PhHS–IHRF2026 “International Symposium on Physical Height Systems and the International Height Reference Frame” will be held in Riyadh, Kingdom of Saudi Arabia from 7 to 9 April 2026. It focuses on methods for observing, estimating and interpreting the Earth’s gravity field and the geoid with special emphasis on height systems, physical height determination and the realization of the International Height Reference System (IHRS) into the International Height Reference Frame (IHRF).

PhHS–IHRF2026 is a Joint IAG Symposium co‑organized by IAG SC2.2 “Geoid, Physical Height Systems and vertical datum unification”, SC2.4 “Gravity and Geoid”, the International Gravity Field Service (IGFS) and the Global Geodetic Observing System (GGOS).

Topics

  • Vertical reference systems in physical geodesy
  • Global and regional realisation of the International Height Reference System (IHRS)
  • Definition and modern realisation of geopotential‑based height systems
  • Unification of height systems at regional and global scales
  • Advances in geopotential theory for geoid determination
  • National geoid models and GNSS/levelling approaches for geoid validation and height conversion
  • Height systems and geoid modelling as essential geodetic infrastructure
  • The geoid as reference surface for Earth system modelling and geodynamics
  • Temporal evolution of physical height systems and the IHRF
  • Mass redistribution and geodynamic effects on vertical datums
  • Geoid and gravity field modeling in Arab countries, Africa and Asia
  • Challenges in geoid, gravity and height data management, dissemination of results and networking of stakeholders
  • Communicating the importance of geodetic infrastructure to stakeholders
  • Regional contributions in Arab countries, Africa and Asia to the global geodesy supply chain
  • Interactions between the IHRF and the ITRF. Where are we and what can be done?
  • Integrated Temporal Spatial Reference Systems for Geodetic Earth Observations in the complex Earth’s Physical Continuum.

Scientific Organizing Team (SOT)

  • George Vergos (SC2.2 Chair, IHRF CC director, IGFS CB Director).
  • Rossen Grebenitcharsky (SC2.2 Vice‑Chair).
  • Riccardo Barzaghi (IGFS President).
  • Laura Sanchez (GGOS President).
  • Hussein Abd‑Elmoataal (SC2.4 Chair).
  • Rene Forsberg.
  • Zuheir Altamimi.

Local Organizing Team (LOT)

  • Sultan Falah AlShahrani (LOC Chair)
  • Mohammed AlArjani
  • Mashael AlHarbi
  • Saad AlQahtani
  • Abdulmohsen AlDosari
  • Saleh AlFaris
  • Eslam Abdulsamie

Contact

Conference Coordination Team: PHHS-IHRF2026@geosa.gov.sa

DATES

  • 25 Oct 2025 | Website launch, session description, call for abstracts.
  • 15 Nov 2025 | Abstract submission open.
  • 30 Nov 2025 | PhHS‑IHRF2026 Registration Open.
  • 30 Nov 2025 | Call for abstracts.
  • 15 Dec 2025 | Geoid School Registration Open.
  • 15 Jan 2026 | Abstract submission deadline.
  • 15 Feb 2026 | Draft schedule and abstract acceptance notifications.
  • 15 Mar 2026 | Registration deadline.
  • 15 Mar 2026 | Final scientific programmers for PhHS‑IHRF2026.
  • 7–9 Apr 2026 | PhHS‑IHRF2026
  • 12–16 Apr 2026 | Geoid School 2026

ABSTRACT SUBMISSION

All colleagues working on the topics of PhHS‑IHRF2026 or related themes are invited to submit an abstract by 15 January, 2026. Abstracts received after this deadline will not be accepted and will not be included in the final programme of the conference. Authors will be informed of the acceptance/rejection of their abstract by email by 15 February, 2026. By submitting an abstract, the author or one of the authors of a joint work is required to complete the online registration before 1 March, 2026. If no registration has been received by that date for one of the authors of the abstract, it will not be included in the meeting programme. If authors know that their presentation will not be presented, they are asked to withdraw their abstract as soon as possible (by contacting Abstracts email).

There is intention to have conference proceedings for the PhHS-IHRF2026 conference, in the IAG Symposia Series. During abstract submission, authors will be asked whether they intend to submit a full proceedings article, after the conclusion of the conference. The IAG Symposia Series is published Open Access, and free of charge to the authors. The cost of publication is borne by the IAG. All presentations, poster and oral, are eligible. All Symposia Series volumes are peer reviewed and submitted for indexing.

Submitting an abstract to the PhHS-IHRF2026 conference bears the obligation for at least one of the co-authors to register to the conference. If no registration for the conference is received, the respective abstracts will be removed from the conference scientific program.

Abstracts cannot be submitted by fax or email.

Authors can use the PhHS-IHRF2026 Abstract Template as a guide to draft their abstracts.

When submitting an abstract, authors are required to provide the following information:

  • Title
  • Author(s)
  • Affiliation(s)
  • Main body of the abstract (up to 500 words).
  • Abstract text (maximum 300 words)
  • Keywords (please include 3–5 keywords).

Submit Abstract

Licence and copyright

The following licence and copyright agreement are valid for any abstract submitted to the PhHS-IHRF2026 Symposium: In submitting the abstract, the authors certify that (1) they are authorised by their co-authors to submit the abstract; (2) they secure the right to reproduce any material that has already been published or copyrighted elsewhere; (3) they agree to the following license and copyright agreement:

  • Copyright on any abstracts is retained by the author(s).
  • Authors grant any third party the right to use the abstract freely if its original authors and citation details are identified.
  • The abstract is distributed under the Creative Commons Attribution 3.0 Unported Licence.

Please download the meeting handbook for more details

REGISTRATION

Welcome and Pre‑Registration Notice

Thank you for your interest in participating in the International Symposium on Physical Height Systems and the International Height Reference Frame (PhHS IHRF 2026), to be held in Riyadh, Kingdom of Saudi Arabia, from 7 to 9 April 2026.

We are delighted by the enthusiasm shown by professionals, researchers, and students from around the world who wish to join this event.

If you are interested in attending, please fill out the short Expression of Interest Form below. This will help us keep you informed about the registration process and key updates as they become available.

Formal registration for the symposium will open on 30 November 2025. Once registration is live, all pre‑registered participants will receive an email notification with instructions for completing their registration.

We look forward to welcoming you to Riyadh in 2026 and to your participation in this important IAG event.

Stay connected – register your interest today!

Travel Award

The IAG provides the opportunity for young scientists from developing countries to receive a travel award for the PhHS-IHRF2026 Symposium.

Please, refer to the IAG website https://geodesy.science/iag/awards/iag-travel-award/ for the detailed rules and procedures to apply for an IAG travel award.

Venue

Venue details will be announced soon.

Contact

Conference Coordination Team: PHHS-IHRF2026@geosa.gov.sa

GEOID SCHOOL 2026

Event Details

Date: April 12–16, 2026

Location: General Authority for Survey and Geospatial Information (GEOSA), Saudi Arabia

Language: English.

About the School

The intensive week‑long Geoid School is aimed at training students, early‑career scientists, and professionals from national agencies, universities, and research institutes by providing them with the knowledge and skills necessary for computing and applying gravimetric geoids in various scientific and technical geodetic applications. Participants will gain valuable insights into the latest advancements in geoid determination and have the opportunity to establish international collaboration and interaction with experts in gravity field modelling.

Moreover, the School emphasizes the importance of interaction between the scientific community and cartographic agencies responsible for the development and modernization of national geodetic infrastructure. This collaboration ensures the effective translation of scientific research into practical applications for the improvement of regional and local geodetic networks.

Attendees should have basic knowledge of the following topics:

Attendees should have basic knowledge of the following topics:

  • Concepts of Physical Geodesy
  • Concepts on gravimetric measurements
  • Altimetric data concepts
  • Concepts on calculation and use of Digital Elevation Models
  • Concepts on Global Geopotential Models

Prior to school it is suggested to consider reading on of these books:

  • Heiskanen, W.A. and Moritz, H. (1967) Physical Geodesy. W.H. Freeman and Company, San Francisco.
  • Torge, W., & Müller, J. (2012). Geodesy. In Geodesy. From Gruyter.

Lecturers

Lecturers will be announced soon.

Registration for GEOID School 2026

Thank you for your interest in participating in the GEOID School 2026 to be held in Riyadh from 12 to 16 April 2026.

Please note that the number of seats is limited (45 Seats), and early registration is highly encouraged to secure your spot. Registration will officially open on 15 December 2025.

Additional details including course content, Lecturers and participation requirements will be provided soon.

Once all available seats are reserved, the registration process will be closed.

Be tuned, follow-up the registration process and secure your place!

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