Marine geodetic (surveying) advice and expertise

Learn about nautical geodesy, maritime limits and boundaries, calculations for charts, consultations and expert testimony.

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About nautical geodesy

Nautical geodesy is the science that deals with the measurement and representation of the earth. It uses 4 dimensions (x, y, z and time), and applies them to hydrographic surveying. This is used in the production of:

  • charts
  • tide tables
  • other nautical products and services

Nautical geodesists at the Canadian Hydrographic Services (CHS) provide technical advice and expertise in:

  • maritime limits and boundaries
  • survey, datum and geodetic calculations
  • consultations for government departments and other organizations
  • testimony in civil litigation or prosecution of individuals or organizations regarding violations and infractions in Canadian waters

Maritime limits and boundaries

The CHS calculates the limits of Canada's maritime zones from baselines. We're able to describe these baselines by using data we collect from hydrographic surveys.

Our hydrographers are technical experts on the geographic coordinates of the baselines. They address questions on the limits of Canada's maritime zones through our:

  • tools
  • marine geodetic knowledge

Electronic navigational charts

The CHS provides expert advice to assist in the creation of electronic navigational charts (ENCs). These charts depict maritime boundaries and limits.

Transboundary ENCs produced in collaboration with the other countries will include the maritime boundary claims of both nations. This is important as paper charts depict only Canada's position with respect to the maritime boundary line.

Boundary enforcement

CHS nautical geodesists act as technical experts in legal matters involving Canadian boundaries and limits enforcement. They use our charts when resolving international boundary disputes, such as those in the:

  • Lincoln Sea with Denmark
  • Beaufort Sea with the U.S.

Calculations for charts

CHS hydrographers and nautical geodesists perform calculations to assist in data acquisition and datum transformation phases of chart production. To do this they work with:

  • geospatial data
  • map projections
  • transformation and coordinate systems

The CHS applies nautical geodesy to:

  • hydrographic surveying
  • water levels publications
  • nautical chart production

CHS navigational charts are developed from data acquired during hydrographic surveys. Hydrographers use a variety of equipment to measure:

  • depths and heights
  • water levels and vertical datum
  • survey vessel positioning and orientation

Geodetic models of earth

Datum transformations of geographic coordinates to newer models are needed as geodetic models of the earth evolve. To properly operate these transformations, our hydrographers must have expert knowledge of:

  • hydrography
  • marine sciences
  • nautical geodesy

Datum transformation involves the shifting of a horizontal datum from an older model of the earth to the current horizontal datum. This datum is important because it's compatible with geographic positions obtained from the Global Navigation Satellite System.

Consultation services

CHS nautical geodesists provide technical advice and expertise to:

  • other government departments
  • licensees (private companies) who receive CHS intellectual property licences

CHS provides advice, data and expertise to other federal departments and agencies. This may regard nautical charts and maritime boundaries and limits that are needed for the exercise of Canadian jurisdiction in areas such as:

  • fish habitat
  • national security
  • marine navigation
  • resource management
  • environmental protection

CHS also assists in establishing national marine policies, regulations and standards by working with:

  • Transport Canada
  • Canadian Council on Geomatics

Expert testimony

CHS charts are used in legal actions or prosecutions of those who have broken Canadian law.

Our nautical geodesists provide expert advice and assistance to legal counsel and Crown prosecutors on:

  • surveys
  • nautical charts
  • maritime boundaries and limits

CHS experts may be requested to testify in cases involving the Crown or third parties. They may also be interviewed by the Transportation Safety Board of Canada on marine accident investigations.

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