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Part of Land surveys

Geodetic control unit

The Geodetic Control Unit manages the Alberta Survey Control network within the framework of the Canadian Spatial Reference System (CSRS).

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Land surveys

Overview

The Alberta Survey Control network consists of approximately 29,500 Alberta Survey Control Markers (ASCMs) throughout the province making up the provincial spatial referencing system. The markers are typically a 2.5 m steel post with a brass tablet attached stamped with an identifying number.

  • Positional data includes both horizontal and vertical co-ordinates as well as details about the marker’s relationship to other markers in a defined area.
  • Co-ordinates are published in geographical format (latitude and longitude) along with a height above sea level.
  • Co-ordinates are also available as Universal Transverse Mercator (UTM) and 3-degree Transverse Mercator (3TM) mapping plane values.

Alberta Survey Control products

The Geodetic Control Unit manages the survey control network as per the Surveys Act. The Unit uses specific products to publish the co-ordinates and other attributes of ASCMs.

The products come from the Multipurpose Alberta Survey Control Operations and Tasks (MASCOT) system.

ASCM identification cards

ASCM identification (ID) cards are referenced to the original derivation of the North American Datum 1983 (NAD83) and the Canadian Geodetic Vertical Datum of 1928 (CGVD28). They contain detailed information about individual ASCMs, including:

  • horizontal position
  • elevation
  • gravity field data
  • location description
  • adjacent marker information
  • revision history

To see what an ASCM ID card looks like, view this Sample ASCM ID Card.

For more information, see the Alberta Survey Control Products Manual.

ASCM condition report

When referencing to ASCMs, Alberta Land Surveyors must complete the following form:

The completed form can be mailed or emailed to the contact information found below in the Contacts section.

ASCM index maps

The Geodetic Control Unit has created digital ASCM index maps by scanning the original urban and rural mylar-format versions.

The rural versions provide a graphical representation of ASCMs on a 1:250,000 scale base map. There are fifty 1:250,000 scale maps available, based on the National Topographic System (NTS) map grid. They are identified by the latitude and longitude of the southeast corner (53112, 58118, etc.).

These maps show where ASCMs are in relation to various base mapping features, such as:

  • airports
  • the Alberta Township System
  • geo-administrative boundaries (municipal and Canada lands)
  • hydrography
  • railways
  • road networks

They also include street names and major facilities such as schools and hospitals.

How to get them

You can get all scanned rural index maps free of charge from the Geodetic Control Unit.

For more information, see ASCM Data Disclaimer.

Files available

Each file below contains a Readme text file and the associated scanned index map image. These are compressed files.

50112 rural index map

The canal rehabilitation (Canal Rehab) within the 50112 rural index map is a special case. The ASCMs associated with the canal rehabilitation on this map includes the following areas, all west of the 4th meridian:

  • Township 21
  • Township 22
  • Township 23
  • Range 26
  • Range 27

The detail of the canal rehabilitation area is available. (see 50112_CANAL_REHAB.zip). You will need special software to decompress the files in this map image.

Urban versions provide a graphical representation of ASCMs on a 1:20,000 scale base map. There are 73 urban municipalities available. Each municipality is shown on a single map sheet, except for Edmonton (9 map sheets) and Calgary (12 map sheets).

The urban index maps show the locations of integrated ASCMs in relation to:

  • airports
  • the Alberta Township System
  • geo-administrative boundaries (municipal and Canada lands)
  • hydrography
  • railways
  • road networks

They also include street names and major facilities such as schools and hospitals.

How to get them

You can get all scanned urban index maps free of charge from the Surveys Section.

For more information, see ASCM Data Disclaimer.

Files available

Special cases

The Fort McMurray and Medicine Hat urban index maps are special cases.

Fort McMurray

The Fort McMurray index map consists of:

  • FORT_MCMURRAY_UPPER.TIF
  • FORT_MCMURRAY_LOWER.TIF
  • FORT_MCMURRAY.TIF

Most of Fort McMurray is included in the UPPER image. The scanning date and last revised date are included in the LOWER image.

Both the UPPER and LOWER images have been included in the image data set. Also, the Unit has combined the UPPER and LOWER images to create a single TIFF image showing the whole Fort McMurray index map. There may be some distortion in the FORT_MCMURRAY.TIF image.

Medicine Hat

Similar to Fort McMurray, the Medicine Hat index map is divided into:

  • MEDICINE_HAT_LEFT.TIF
  • MEDICINE_HAT_RIGHT.TIF

The majority of the Medicine Hat index map is included in the LEFT image. The scanning date and last revised date are included in the RIGHT image.

Both the LEFT and RIGHT images have been included along with a combined image (MEDICINE_HAT.TIF - produced by Unit) in the data set. There may be some distortion in the MEDICINE_HAT.TIF image.

General geodetic information

The Surveys Section provides geodetic fact sheets, guides and manuals.

Fact sheets

You can find a list of fact sheets that describe horizontal datums used in Alberta, the Canadian Base Network, mapping planes and more on the Open Government Portal at:

Digital data format requirements

Survey control observational data being submitted to the Geodetic Control Unit must conform to a specific format. Information on the data format required can be found at Digital Data Format Requirements.

EDM baseline guidelines

The Geodetic Control Unit provides helpful guidelines about Electronic Distance Measurement (EDM) in Alberta.

Electronic Distance Measurement (EDM) Calibration Baseline Lengths has information about the four Alberta EDM calibration baselines.

These are:

  • Lethbridge
  • Calgary
  • Edmonton
  • Grande Prairie

The pillar-to-pillar (slope distance) lengths for these four baselines come from the Canadian Geodetic Survey, Natural Resources Canada.

On each listing, the adopted date shows when the slope distances were last measured.

Guidelines for Electronic Distance Measurement Calibration Baseline Surveys in Alberta explains how to do an EDM calibration baseline survey. Surveyors can use these guidelines to make sure their equipment is working to manufacturers’ specifications.

These guidelines also explain requirements for submitting your calibration survey data to the Geodetic Control Unit for evaluation.

Important notice for users of Alberta EDM calibration baselines

All users of the Alberta EDM calibration baselines are responsible for any damages to any property (public or private) that may occur when using the baselines. In addition, users should exercise normal traffic safety precautions while conducting calibration surveys. Any damage or activities which may result in damage to the baseline must be reported to the Geodetic Control Unit.

Standards for using GPS to establish ASCMs

The Standards, Specifications & Guidelines for Establishment and Maintenance of Alberta Survey Control using GPS manual is used to establish and integrate survey control markers into the provincial spatial referencing system using Global Navigation Satellite Systems (for example: GPS, etc.).

Also, for users who wish to validate their GPS survey system, they can use either of the following GPS validation basenets:

Canadian Geodetic Reference System Committee

The Canadian Geodetic Reference System Committee (CGRSC) is a federal-provincial-territorial working committee of the Canadian Council on Geomatics. The CGRSC plans and coordinates maintenance to improve the Geodetic Reference System in Canada as a standard for the positioning of geographically referenced data related to the Canadian land mass and territorial waters. The Geodetic Control Unit is Alberta’s representative to the CGRSC.

The CGRSC maintains a website that users of the provincial reference system in Alberta can reference when looking for the latest information on geodetic reference systems, including:

  • coordinate transformations
  • geodetic control networks
  • Global Navigation Satellite System (GNSS) augmentation
  • North American Reference Frame (NATRF) 2022
  • standards and guidelines
  • various publications related to geodetic control

This site includes contact information for the various provincial, territorial and federal CGRSC members. Visit:

NAD27 ASCM listings

Only markers with published NAD27 co-ordinate values on or before May 31, 1994 are included in these North American Datum 1927 (NAD27) co-ordinate listings for ASCMs.

Note:

ASCMs integrated into the provincial spatial referencing system after May 31, 1994, contain integrated North American Datum 1983 (NAD83) coordinate values only. Therefore, no transformed (NAD83 to NAD27) coordinated values are included in the listings for these markers. However, users can derive NAD27 coordinate values by transforming integrated NAD83 geographic or Transverse Mercator coordinates to NAD27 using the National Transformation version 2.0 (NTV2).

For more information, see ASCM Data Disclaimer.

The NAD27 data is split into four Microsoft Excel files. Each file is sorted by ASCM number. The data types for each ASCM are listed with these ASCM Data Types.

Compilation dates appear on the first line of the files.

The files include:

NAD83 (CSRS) subset data

The Microsoft Excel file NAD83(CSRSv7_E2010_CGVD2013_Provincial_HPN_data.xlsx includes urban and rural markers. They are sorted by ASCM number as defined in Column A of the listing. For each ASCM, the data types included are listed with these ASCM Data Types. Each file’s compilation date can be found on the first line.

If a marker is part of the Canadian Base Network (CBN) in Alberta, the ASCM information is highlighted in red.

Find more information about the Alberta Provincial High Precision Network

The information in this file is current up to March 2021. For the most current data, contact the Geodetic Control Unit.

NAD83(CSRS)v7 Epoch 2010 ASCM

The Microsoft Excel NAD83(CSRS)v7 Epoch 2010 coordinate and CGVD2013 elevation data are published for 32,971 ASCMs. The coordinate and elevation information for the ASCMs is based on the NAD83V7.0.0.AB.1 provincial readjustment of the Alberta Survey Control Network. For each ASCM, the data types included are listed with these ASCM Data Types.

Transformation grids in Alberta

Contact

Hours: 8:15 am to 4:30 pm (open Monday to Friday, closed statutory holidays)

For information on any of these products, contact:

Geodetic Control Unit
Phone: 310-LAND (5263)
Toll free: 1-833-310-5689
Email: [email protected]

To send your completed ASCM Condition Report form:

Email: [email protected]

Address:
Geodetic Control Unit, Surveys Section
15th Floor, Oxbridge Place
9820 106 Street NW
Edmonton, Alberta  T5K 2J6

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