This edition comprises four articles and one note. Two articles relate to positioning systems – one being the Global Navigation Satellite System (GNSS) and various techniques to obtain accurate positions to the ellipsoid to remove the need for accurate tidal benchmarks. The first article is from the US and discusses various field techniques and reports on their findings. The second paper from Portugal, published as the fourth article, describes the OMEGA positioning system used 30 years ago and describes an error in the broadcast position corrections. The paper describes how the error was verified using long line geodetic calculations. These two articles showcase the advances in positioning technology.
The second article from Brazil discusses the efforts of the Brazilian Hydrographic Service to update its survey platforms and the collaborative effort with other government agencies and the private sector that is required to secure the funding and ongoing practices to ensure the platforms are multi-use and maximised for operations. The paper describes the challenging Brazilian waterways and the impact these have on the construction of the platforms and the type of equipment required in these waters.
The third article outlines a detailed study of a seafloor basin structure using various seismic and gravity anomaly data and interpretation techniques to confirm the thickness of the continental crust in various parts of the Farallon Basin in the South California Gulf.
A final paper in the Notes section describes the activities of the General Commission for Survey (GCS) in the Kingdom of Saudi Arabia to establish and grow a national hydrographic survey and charting capability. It is exciting to see a relatively new organisation coming to terms with what it takes to establish this capability and to set forth an aggressive capacity building and survey and charting program to improve the existing scant coverage in such a critical navigation area.
It is very pleasing to see five high quality papers covering many different aspects of our industry submitted from all parts of the world. Our industry is global, yet it has in reality, a small but highly dedicated number of professionals. On behalf of the Editorial Board, I hope that this edition is of interest to you and may inspire you to submit a future paper on the work that you have done or are currently engaged in. Sharing knowledge is really worthwhile.
Thank you to the authors for your contributions and to my colleagues who provided peer reviews for the Articles in this edition.
Ian W. Halls
Editor