Global Navigation Satellite Systems (GNSS) have revolutionised the way we navigate and locate ourselves on the surface of the Earth. However, GNSS signals are prone to interference and one of the most significant sources of interference is increased ionospheric activity.
Information Notes
IMCA produces a range of materials for its members as information notes, covering safety, technical, regulatory, commercial and various other issues relevant to its members.
Members can access all of these materials by logging in to this site. Non-members can view titles, for information, and a small number of individual articles deemed of wider public interest.
Browse our most recent information notes below, or use the filters to view our archives by subject and/or year.
Select some filters
Information Notes
GPS systems – Warning of interference
The United States Department of Transportation Maritime Administration (MARAD) has issued revised advisory notice 2020-016-Various-GPS Interference on multiple instances of significant GPS interference that have been reported worldwide. This interference is resulting […]
Common industry technical specification for USBL Positioning systems
The IOGP Geomatics Committee has released Report 624-01 – Common Industry Technical Specification for the Calibration and Verification of Ultra Short Baseline (USBL) Positioning Systems. The Report has been produced by the Surveying and Positioning Subcommittee’s Ultra Short Base Line (USBL) Task Force, which consisted of professionals from oil and
This content is only available to members.
Shallow water survey operations
Members in certain areas, notably, parts of the Middle East, have suggested the possibility of IMCA guidance on shallow water surveying being developed. The Offshore Survey Division Management Committee (OSDMC) notes that there are existing resources available on this topic, which will be of use and interest to members. This
This content is only available to members.
GNSS interference, jamming and spoofing
This briefing provides a brief overview of global navigation satellite system (GNSS) interference, jamming and spoofing.Interference is the unintentional transmission of signals stopping the reception of the GNSS signals.Jamming is the intentional interference of the GNSS signal reception to deny the receiver GNSS signals.Spoofing is the practice of tricking a
This content is only available to members.
Sustained load cracking in aluminium manufactured from aluminium alloys HE30/AA6082 and AA6351
This information note is to make members aware of IMCA Safety Flash 07/18, which is copied below. A susceptibility to sustained load cracking (SLC) has been identified in cylinders manufactured […]
IOGP Report 373-24, Geomatics Guidance Note 24 – Vertical data in oil and gas applications
The International Association of Oil & Gas Producers (IOGP) has released Geomatics Guidance Note 24 on Vertical data in oil and gas applications. This guidance note discusses issues associated with vertical Coordinate Reference Systems (CRSs), in particular those related to coordinate operations (coordinate conversions and coordinate transformations) and metadata. It is
This content is only available to members.
IOGP publishes SSDM V2 and V1.1 of P6/11 Seismic bin grid data exchange format
The International Association of Oil & Gas Producers (IOGP) has made new and recent releases of SSDM V2 and P6/11 V1.1. Please see these two news items (also published via IOGP pages: www.iogp.org/blog/category/press-releases/geomatics-press-releases), which are aimed at its stakeholders and the wider oil & gas industry, notifying us of: First,
This content is only available to members.
IOGP Report 373-23, Geomatics Guidance Note 23 – Web Mercator
The International Oil & Gas Producers Association (IOGP) has published Report 373-23, Geomatics Guidance Note 23 – Web Mercator. This guidance note aims to clarify the main issues associated with the usage of the Web Mercator Coordinate Reference System (CRS), clear up misunderstandings about what it is, and warn against
This content is only available to members.
IOGP Technical Notes on Guidelines for the conduct of offshore drilling hazard site surveys
In 2013, the International Association of Oil & Gas Producers (IOGP) published Guidelines for the conduct of offshore drilling hazard site surveys (IOGP No. 373-18-1). This describes oilfield good practice for conducting geophysical and hydrographic site surveys of proposed offshore drilling locations. IOGP’s new Technical Notes publication (IOGP No. 373-18-2)
This content is only available to members.
IOGP releases version 1.1 of P1 and P2 formats for Geophysical Position Data Exchange
The International Association of Oil and Gas Producers (IOGP) has released version 1.1 of its P1 and P2 geophysical position data exchange formats. Originally released in 2012 to replace the UKOOA P1/90 and P2/94 formats, the revised versions incorporate industry feedback from the first release and provide greater flexibility –
This content is only available to members.
Exports of certain equipment and technology to Russia
On 31 July the Council of the European Union agreed adoption of agreed restrictive measures in view of Russia’s actions destabilising the situation in eastern Ukraine. This decision gives legal value to an agreement reached at the Committee of Permanent Representatives on Tuesday 29 July and announced by European Council President
This content is only available to members.
OGP publishes revised versions of geophysical position data exchange formats – the ‘P’-formats
Originally issued with the following reference(s): IMCA S 02/13
This content is only available to members.
Major new addition to the EPSG Geodetic Parameter Dataset
Originally issued with the following reference(s): IMCA S 02/12
This content is only available to members.
Lithium-thionyl chloride (Li/SOCL₂) batteries
Originally issued with the following reference(s): IMCA S 07/11
This content is only available to members.
Heightened ionospheric activity in equatorial/polar regions
Originally issued with the following reference(s): IMCA M 21/11, IMCA S 05/11
This content is only available to members.
Possible GPS interference – LightSquared
Originally issued with the following reference(s): IMCA S 04/11
This content is only available to members.
Seabed Survey Data Model (SSDM) – Version 1
Originally issued with the following reference(s): IMCA S 02/11
This content is only available to members.
OGP and SEG Revise Their P1 and P2 Positioning Exchange Formats, and Set a Common Standard
Originally issued with the following reference(s): IMCA S 03/10
This content is only available to members.
Global navigation satellite system (GNSS) receiver interference
Originally issued with the following reference(s): IMCA M 12/09, IMCA S 04/09
This content is only available to members.
25 post(s)