GO-ITS 544TES CGVD2013 official geodetic vertical datum for Ontario

1. Introduction

Government of Ontario Information Technology (GO-IT) Standards are the official publications on the IT standards adopted through the Office of the Corporate Chief Information Officer (OCCIO) and IT Executive Leadership Council (ITELC) for use across the government’s information and information technology (I&IT) infrastructure.

These publications support the responsibilities of the Treasury Board Secretariat for coordinating standardization of I& in the Government of Ontario. In particular, GO-IT Standards describe where the application of an IT standard is mandatory and specify any qualifications governing the implementation of the IT standards.

2. Summary

2.1 Standard name and description

This document defines the official geodetic vertical datum for Ontario as the Canadian Geodetic Vertical Datum of 2013 (CGVD2013) through this GO-IT Standard 544TES.

2.2 Background and rationale

This GO-IT Standard is established to define the Canadian Geodetic Vertical Datum of 2013 (CGVD2013) as the official vertical datum for Ontario Public Service (OPS) Ministries and Agencies and those agencies and authorities (e.g., municipalities, Conservation Authorities, and non-provincial government agencies) cooperating with or submitting data to OPS ministries. Presently, the Canadian Geodetic Vertical Datum of 1928 (CGVD28) is the de facto geodetic vertical datum for the province of Ontario.  Adopting CGVD2013 in Ontario will support the national “Height Modernization” initiative being undertaken by the federal government (Canadian Geodetic Survey (CGS) – Natural Resources Canada (NRCan)) and other provincial geodetic agencies across Canada. CGVD2013 elevations can be precisely determined using Global Navigation Satellite System/Global Positioning System (GNSS/GPS) technologies and are determined in combination with the use of a modern and accurate gravimetric geoid model.  CGVD28 primarily relied upon traditional leveling techniques to establish elevations (heights) on reference markers (benchmarks).  The nature of establishing elevations using traditional levelling techniques means existing vertical networks often follow roadways or railway lines.  The proliferation of GNSS/GPS technologies in geo-spatial positioning industries has allowed for this accurate method of establishing 3-D or vertical positions in a more cost-effective and efficient manner anywhere within the province or country to a high level of accuracy.

Once CGVD2013 is officially adopted, CGVD28 will still be accepted for use for existing/legacy projects or activities, or data sets as needed, but will transition to historical status (not accepted for use) five years after GO-IT Standard 544TES became official (see Document History section for official approval date). Prior to the end of the five-year transition period, CGVD28 legacy data, that will continue to be used, must be updated/transformed to CGVD2013.

The expected benefits and results of the GO-IT Standard 544TES are:

• GNSS/GPS is a more time and cost-effective method of establishing elevations (heights) on reference markers (benchmarks) compared to leveling.
• CGVD2013 will allow for easy expansion of vertical reference networks in Northern Ontario.
• Adopting CGVD2013 will bring Ontario in-line with moving towards full “Height Modernization” within Canada.

2.3 Target audience

The target audience for this document includes, but is not limited to:

• All Ontario Ministries/IT Clusters,
• Conservation Authorities,
• The Association of Ontario Land Surveyors (AOLS),
• Ontario Municipalities,
• GIS and GNSS/GPS service providers and users,
• Professional Surveyors and Engineers in Ontario, and
• the Geomatics Community of Ontario.

2.4 Scope

2.4.1 In scope

The scope of this document is to:

• Adopt CGVD2013 as the official geodetic vertical datum for OPS ministries and agencies through GO-IT Standard 544TES.

2.4.2 Out of scope

The out of scope of this document is to:

• Provide implementation support for non-OPS entities.
• Specify how CGVD2013 will be implemented.
• Updating the affected existing GO-IT Standard documents – 541TES, 542TES, and 543TES (previously 45.1, 45.2 and 45.3).

Note: The revisions proposed above to GO-IT Standards 541TES, 542TES, and 543TES (previously 45.1, 45.2 and 45.3) have been approved by ITELC on October 12, 2023, in support of adopting CGVD2013 as the official vertical datum of Ontario through GO-IT Standard 544TES.

2.5 Applicability statements

2.5.1 Organization

All Ministries and I&IT Clusters are subject to Government of Ontario IT Standards.

All adjudicative and advisory agencies are subject to Government of Ontario IT Standards.

All other agencies that are using OPS information and information technology products or services are required to comply with Government of Ontario IT standards if they are subject to either the Governance and Management of Information Technology Directive or Government of Ontario IT Standards by memorandum of understanding.

As new GO-IT Standards are approved, they are deemed mandatory on a go-forward basis (go-forward basis means at the next available project development or procurement opportunity).

When implementing or adopting any Government of Ontario IT standards or IT standards updates, Ministries, I&IT Clusters and applicable agencies must follow their organization’s pre-approved policies and practices for ensuring that adequate change control, change management, and risk mitigation mechanisms are in place and employed. For the purposes of this document, any reference to Ministries or the Government includes applicable agencies.

2.5.2 Other applicability

Municipalities, local or regional governments or agencies do not need to comply with this standard individually, unless they submit data to OPS ministries or enter into a joint/cooperative projects or initiatives with one or more OPS ministries.

Land Information Ontario (LIO) is a provincial initiative that supports the province-wide sharing of geographic data. LIO provides centralized access to data through a number of tools and services, including the LIO Warehouse, the Ontario Geospatial Data Exchange, the Ontario Land Information Directory, and LIO Internet Mapping.

LIO uses, supports, and maintains georeferencing standards and tools to ensure that public sector organizations are consistently referencing their geographic data holdings to a single modern referencing system that is GPS compatible and used by most GIS users.

2.5.3 Requirement levels

Within this document, certain wording conventions are followed. There are precise requirements and obligations associated with the following terms:

Must - This word, or the terms "required" or "shall", means that the statement is an absolute requirement.

Should - This word, or the adjective "recommended", means that there may exist valid reasons in particular circumstances to ignore the recommendation, but the full implications (for example, business functionality, security, cost) must be understood and carefully weighed before choosing a different course.

3. Technical specification

The following requirements apply to all I&IT assets and operations within the scope of the Governance and Management of Information Technology Directive.

3.1 Mandatory

CGVD2013 (Canadian Geodetic Vertical Datum of 2013)

The Canadian Geodetic Vertical Datum of 2013 (CGVD2013) was released and made available for use in Canada by the Canadian Geodetic Survey (CGS) – Natural Resources Canada (NRCan) in November of 2013.

Adopting CGVD2013 in Ontario will support the national “Height Modernization” initiative being undertaken by CGS-NRCan and other provincial geodetic agencies across Canada. CGVD2013 is defined by an equipotential surface which represents by convention the coastal mean sea level for North America. This definition comes from an agreement between the United States of America and Canada.

Orthometric heights (elevations) related to CGVD2013 are precisely determined using Global Navigation Satellite System/Global Positioning System (GNSS/GPS) technologies in combination with the accurate geoid model currently recommended by the Canadian Geodetic Survey (presently the Canadian Gravimetric Geoid – 2013 Version A (CGG2013a)). The proliferation of GNSS/GPS technologies in geo-spatial positioning industries has allowed for this accurate method of establishing 3-D or vertical positions in a more cost-effective and efficient manner anywhere within the province or country to a high level of accuracy.

Once CGVD2013 is officially adopted, CGVD28 will still be accepted for use for existing/legacy projects or activities, or data sets as needed, but will transition to historical status (not accepted for use) five years after GO-IT Standard 544TES became official. Prior to the end of the five-year transition period, CGVD28 legacy data, that will continue to be used, must be updated/transformed to CGVD2013 using the HTv2.0 methodology or tool.

3.2 Non-mandatory

The immediate transformation of existing CGVD28 data sets (including GIS data/layers) is not required. However, any CGVD28 data sets (including GIS data/layers) that continue to be used beyond the five-year transition period must be transformed to CGVD2013 prior to the end of the transition period.

4. Related standards and impacted infrastructure

4.1 Impacts to existing standards

Identify any standards that reference or are referenced by this standard and describe the impact.

Note: The revisions proposed above to GO-IT Standards 541TES, 542TES, and 543TES (previously 45.1, 45.2 and 45.3) have been approved by ITELC on October 12, 2023, in support of the implementation of CGVD2013 as the official geodetic vertical datum for Ontario through GO-IT Standard 544TES.

4.2 Impacts to existing infrastructure

Identify any applications, systems, solutions and technology platforms that could be affected by this standard and describe the impact.

5. Compliance requirements

In order to manage the effectiveness and implementation of this standard, Ministries, I&IT Clusters and applicable agencies are expected to adopt and monitor compliance.

6. Roles and responsibilities

Accountable Role (Standard Owner) Definition

The individual or committee ultimately accountable for the effectiveness of a standard and for its full life-cycle, including development, reviews, revisions, updates, evaluations, and rescindment. Where a committee owns the standard, the committee Chair is accountable for the standard. There must be exactly one accountable role identified.

Accountable Role

Name: Larissa Mathewson-Brake
Title: Director, Mapping and Information Resources Branch
Ministry/I&IT Cluster: Ministry of Natural Resources and Forestry/ Land and Resources I&IT Cluster
Division: Corporate Management and Information

Responsible Role Definition

The organization(s) responsible for the development of this standard. There may be more than one responsible organization identified if it is a partnership/joint effort. (Note: the responsible organization(s) provides the resource(s) to develop the standard).

Responsible Organization(s)

Ministry/I&IT Cluster: Ministry of Natural Resources and Forestry/ Land and Resources I&IT Cluster
Division: Corporate Management and Information
Branch: Mapping and Information Resources Branch

Support Role Definition

The support role is the resource(s) to whom the responsibility for maintaining this standard has been assigned. Inquiries, feedback, and suggestions should be sent to this resource.

Support Role (Editor)

Ministry/I&IT Cluster: Ministry of Natural Resources and Forestry/ Land and Resources I&IT Cluster
Division: Corporate Management and Information
Branch: Mapping and Information Resources Branch
Section: Office of the Surveyor General
Job Title: Provincial Geodesist
Name: Morgan Goadsby
Phone: (705) 313-2789
Email: morgan.goadsby@ontario.ca

2^nd Support Role

Section: Office of the Surveyor General 
Job Title: Geodetic Control Survey Specialist
Name: Hassan Ibrahim
Phone: (437) 881-3190
Email: hassan.ibrahim@ontario.ca

7. Consultations

Areas consulted as part of the development of this standard. Include individuals and committees, councils and/or working groups:

8. Document history

9. Glossary

GPS -

Global Positioning System (USA)

GLONASS -

GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (Russian)

Galileo -

The European Union Global Navigation Satellite System (EU)

GNSS -

Global Navigation Satellite Systems – (including GPS, GLONASS, Galileo, etc.)

GeoDMC -

OPS Geomatics Directors-Managers Committee

GeoTASC -

OPS Geomatics Technical Advisory Sub-Committee of GeoDMC

Geoid -

An equipotential surface representing Mean Sea Level below the Earth’s surface

CGG2013a -

Canadian Gravimetric Geoid 2013 Version A

Orthometric Height -

A height measured along the plumb line from the Geoid to a point on the Earth’s surface

NAD83-ORIG -

North American Datum 1983 – Original realization (Version 0)

NAD83-CSRS -

North American Datum 1983 – Canadian Spatial Reference System – a modern 3-D realization of NAD83

CGVD28 -

Canadian Geodetic Vertical Datum of 1928

CGVD2013-

Canadian Geodetic Vertical Datum of 2013

CGS -

Canadian Geodetic Survey

NRCan -

Natural Resources Canada

CCOG -

Canadian Council On Geomatics

CGRSC -

Canadian Geodetic Reference Sub-Committee – a Sub-Committee of CCOG

MIRB -

Mapping and Information Resources Branch

CMID -

Corporate Management and Information Division

10. Appendices

10.1 Normative references

• Governance and Management of Information Technology Directive (for OPS employees/internal users)
• GO-IT Standards

Specifically, other Geodetic/Geo-referencing GO-IT Standards: GO-ITS 541TES; 542TES; and 543TES.

Note: A normative reference specifies a supporting document or GO-IT Standard (in the case of the Government of Ontario's I&IT infrastructure, often another OPS I&IT authorized publication) that must be read to fully understand or implement the subject matter of the main GO-IT Standard. Such authoritative or de facto references may be external and may, or may not be, owned/controlled by the GO-IT Standard owner.

10.2 Informative references

• Height Reference System Modernization

This document provides details about Height Modernization in Canada

• The Canadian Geodetic Vertical Datum of 2013

This is a PowerPoint presentation provides an overview of Height Modernization and Geodetic Vertical Datums in Canada

• The Canadian Geodetic Vertical Datum of 2013 (CGVD2013)

This is a technical paper about the Canadian Geodetic Vertical Datum of 2013

Note: an informative reference is not normative; rather, it provides only additional background information.