Alberta Survey Control Markers


Identification Information:
Citation:
Citation Information:
Originator: Alberta Environment and Parks, Government of Alberta
Publication Date: Variable
Title: Alberta Survey Control Markers
Publication Information:
Publication Place: Edmonton, Alberta
Publisher: Alberta Environment and Parks, Government of Alberta
Other Citation Details: Alberta Survey Control Marker information is updated on a monthly basis by the Geodetic Control Unit, Surveys and Technical Services Section, Land Dispositions Branch.
Online Linkage: https://alta.registries.gov.ab.ca/spinii/logon.aspx
Description:
Abstract: The implementation of a geodetic reference system is fundamental in the provision of a spatial referencing foundation. The investment in a geodetic reference system yields benefits for those users that require accurate and compatible spatial information for decision making. With the use of spatial information based on an accurate geodetic system, secondary and tertiary users can combine or integrate spatial information and data that may have been produced for other purposes. Geodetic reference systems have traditionally been realized through the definition of datums (horizontal and vertical) and the implementation of monumented reference frameworks. The reference frameworks provided the physical realization of the geodetic reference system. Within Alberta, the horizontal datum has historically been NAD27, and more recently a realization of NAD83 through re-adjustment of historical observations (distances, directions, azimuths, Inertial Survey System (ISS) data and Global Navigation Satellite System (GNSS) data). The Canadian Geodetic Vertical Datum of 1928 (CGVD28) has been used as the reference for the vertical, as derived through orthometric heighting or spirit levelling. For the past 20 years, the monumented network of Alberta Survey Control Markers (ASCMs) has provided the realization of the 3D (horizontal and vertical) geodetic reference system, and hence the foundation for spatial referencing within the province. The existing Alberta Survey Control (ASC) network had its beginning in the province in the 1800's when the township system of survey was established. While this framework adequately served as a basis for land conveyance, it did not provide a suitable reference for land related information. A need to provide a more accurate framework was evident by the early 1960's. Geodetic control in the form of triangulation networks first advanced to the province in the 1920's. A combination of automation of information management, new measurement technology, increased need for higher accuracy and denser coverage began in the 1950's and 1960's. This resulted in geodetic control being established in many of the major urban centres and the foothills of Alberta. In response to an increasing need for higher accuracy and provincial-wide coverage, a 10-year program was implemented in 1976. This program resulted in the establishment of a survey control network at 10 X 20 km spacing with 300-1000 m spacing in urban municipalities. The current ASC network is made up of some 42,000 markers, of which 29,500 are considered current and accessible. These markers represent both federal, provincial (urban and rural) control networks. The federal networks include: primary and secondary Doppler stations; primary triangulation and trilateration networks; and GNSS surveys. Provincially, there are the secondary triangulation and trilateration networks; inertial survey system (ISS) second and third order rural traverses; urban triangulation and trilateration second order networks and High Precision Networks (HPNs) within urban castastral mapping areas; and GNSS surveys within the rural cadastral mapping areas.
Purpose: ASCMs provide the basis for spatial referencing in Alberta. This infrastructure (and related standards) is fundamental for ensuring the compatibility of spatially referenced information from federal, provincial, municipal, and private sources so that it can be merged and exchanged in a seamless manner.
Supplemental Information: The dissemination service for accessing this data is through the Service Alberta - Alberta Land Titles Spatial Information System (SPIN 2). This system can be accessed through the link provided in the Citation Information Online Linkage element within this metadata record. Establishment and maintenance of ASCM's within the ASC network is carried out under the provisions of the Spatial Reference Design Alternatives (SRDA) Initiative. The SRDA defines the spatial referencing system in Alberta as accessible, accurate, having integrity and being responsive to user needs. To realize these four attributes, the initiative defines a combination of the existing monumented control network, the Canadian Base Network and the Active Control System as the environment on which the spatial referencing system is based. Consequently, a move is being made from a monumented control network to a control network, which takes advantage of technology via GNSS and, thereby evolving into a GNSS-based spatial referencing system. The current monumented control system within Alberta does not consistently meet the positioning capabilities of GNSS nor is it cost effective to maintain the density of control of the existing system. Also, the horizontal and vertical datums used to define the existing monumented control system are limited in terms of accuracy and quality. To make the move to a GNSS-based spatial referencing system the province has advocated a switch to the Canadian Spatial Reference System realization of the North American Datum 1983 (NAD83(CSRS)). Additionally, the province recognizes that while the CGVD28 is somewhat distorted, change to an improved version (i.e., North American Vertical Datum 1988 - NAVD88) is not warranted at this time given cost, effort and the existing geoid model. As a result, there is a need to maintain some of the spirit levelling networks, particularly in urban areas, in order to provide a reference for orthometric heighting as well as evaluating the existing geoid model. The role of the Government of Alberta (GOA) in implementing a GNSS-based spatial referencing system will be as a coordinator and facilitator. For example, the GOA continues to liaise with Geomatics Canada in implementing NAD83(CSRS), coordinate standards' development, distribute coordinate information, and promote the move to NAD83(CSRS). However, other public and/or private agencies will be responsible for delivery of differential GNSS services. Also, municipalities will take on the role of project design and evaluation when maintaining the local spatial referencing system. Strategies to support the above roles include a spatial referencing system based on NAD83(CSRS), modelling of the 0.10 m to 0.20 m average coordinate difference between the current definition of NAD83 within Alberta (NAD83(Adopted)) and NAD83(CSRS), derivation and maintenance of a subset of existing control markers on NAD83(CSRS), integration of municipal High Precision Network (HPN) initiatives to NAD83(CSRS), discouraging placement of monumented control except in support of an HPN, revision of survey regulations and development of standards and guidelines related to integration using differential GNSS services. The GOA continues to provide support to municipalities for maintenance activities in the short-term while looking to the municipality (or their designate) to take over the duties of project design, pre-analysis, editing and analysis of data in the long-term. Also, the GOA continues to carry out final integration and publishing of all coordinate and non-coordinate marker information. Over the long-term, the GOA will continue to maintain and support the provincial surveying utilities (i.e., EDM Calibration Baselines, GNSS Validation Networks).
Time Period of Content:
Time Period Information:
Range of Dates/Times:
Beginning Date: 1927
Beginning Time: unknown
Ending Date: unknown
Ending Time: unknown
Currentness Reference: ground condition
Status:
Progress: Complete
Maintenance and Update Frequency: Monthly
Spatial Domain:
Bounding Coordinates:
West Bounding Coordinate: -121.000000
East Bounding Coordinate: -109.000000
North Bounding Coordinate: 60.000000
South Bounding Coordinate: 48.000000
Keywords:
Theme:
Theme Keyword Thesaurus: ISO 19115 Topic Category
Theme Keyword: location
Place:
Place Keyword Thesaurus: None
Place Keyword: Alberta
Access Constraints: Access Constraints are subject to the terms and conditions outlined on the SPIN 2 website.
Use Constraints: Use Constraints are subject to the terms and conditions outlined on the SPIN 2 website.
Point of Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Alberta Environment and Parks, Government of Alberta
Contact Electronic Mail Address: AEP.GDAMetadata@gov.ab.ca
Hours: 08:15 to 16:30 Monday to Friday
Contact Address:
Address Type: mailing address
City: Edmonton
State or Province: Alberta
Postal Code: T5K 2J6
Country: Canada
Address: 15th Floor Oxbridge Place
Address: 9820 - 106 Street NW
Security Information:
Security Classification System: Government of Alberta Data and Information Security Classification
Security Classification: Protected A
Cross Reference:
Citation Information:
Originator: Natural Resources Canada - Geomatics Canada - Geodetic Survey Division
Publication Date: Unknown
Publication Time: Unknown
Title: Canadian Spatial Referencing System Database
Other Citation Details: This is a Federal database that contains coordinate and elevation data for federal survey control markers across Canada (including Alberta).
Data Set Credit: Alberta Environment and Parks, Government of Alberta
Data Quality Information:
Attribute Value Accuracy Information:
Attribute Accuracy Report: Attribute information is provided via ASCM Condition Reports that are certifed by Alberta Land Surveyors, Professional Engineers, and other technical professionals.
Quantitative Attribute Accuracy Assessment:
Attribute Accuracy Value: 100 %
Attribute Accuracy Explanation: It is assumed that the information provided by the professionals outlined above is certified correct. This includes provision of instructions to users on how to fill out the Condition Report.
Logical Consistency Report: Coordinate and elevation data created and maintained by various surveying processes (conventional and GNSS surveying techniques) resulting in formal integration into the provincial geodetic spatial referencing system by least-squares adjustment.
Completeness Report: The coordinate and elevation data is derived from a rigorous process used to define the accuracy (relative and absolute) of the Alberta Survey Control Markers.
Positional Accuracy:
Horizontal Positional Accuracy:
Horizontal Positional Accuracy Report: The accuracy of the ASCMs is based on the results of the least squares adjustment process looking at the relative and absolute position values. This is presented in the form of order 1, order 2, order 3, order 4, and order u for horizontal integration.
Quantitative Horizontal Positional Accuracy Assessment:
Horizontal Positional Accuracy Value: Varies according to order.
Horizontal Positional Accuracy Explanation: The order is derived based on the 1978 EMR Specifications Document from Natural Resources Canada, Geomatics Canada, Geodetic Survey Division. For more information, contact the Geodetic Control Unit as identified in the contact information section of this metadata record.
Vertical Positional Accuracy:
Vertical Positional Accuracy Report: For vertical, the accuracy is a two function determination based on the methodology used to integrate the ASCM (i.e., spirit levelling versus ISS) and to whether the marker has been formally integrated (i.e., INTEGRATED, NON-INTEGRATED, etc).
Quantitative Vertical Positional Accuracy Assessment:
Vertical Positional Accuracy Value: Varies according to the surveying methodology.
Vertical Positional Accuracy Explanation: For more information, contact the Geodetic Control Unit as identified in the contact information section of this metadata record.
Lineage:
Source Information:
Source Citation:
Citation Information:
Originator: Alberta Environment and Parks, Government of Alberta
Publication Date: 1988
Publication Time: Unknown
Title: Multipurpose Alberta Survey Control Operations and Tasks (MASCOT) Survey System
Type of Source Media: Digital data contained within the MASCOT database.
Source Citation Abbreviation: MASCOT
Source Contribution: The Multipurpose Alberta Survey Control Operations and Tasks (MASCOT) Survey System is a database that allows for data validation, integration, management and publication system of ASCM information.
Process Step:
Process Description: The coordinate (including elevation) and non-coordindate data (i.e., physical location and condition of an ASCM) is extracted from the MASCOT database and then exported to a flat ASCII file.
Process Date: on-going
Process Contact:
Contact Information:
Contact Person Primary:
Contact Organization: Alberta Environment and Parks, Government of Alberta
Contact Electronic Mail Address: AEP.GDAMetadata@gov.ab.ca
Hours: 08:15 to 16:30 Monday to Friday
Spatial Reference Information:
Horizontal Coordinate System Definition:
Geographic:
Latitude Resolution: 0.00001 arc seconds
Longitude Resolution: 0.00001 arc seconds
Geographic Coordinate Units: Degrees, minutes, and decimal seconds
Geodetic Model:
Horizontal Datum Name: North American Datum of 1983 (Original)
Ellipsoid Name: Geodetic Reference System 80
Semi-major Axis: 6378137.0
Denominator of Flattening Ratio: 1/298.257222101
Vertical Coordinate System Definition:
Altitude System Definition:
Altitude Datum Name: Canadian Geodetic Vertical Datum of 1928
Altitude Resolution: 0.001
Altitude Units: meters
Altitude Encoding Method: Explicit elevation coordinate included with horizontal coordinates
Entity and Attribute Information:
Detailed Description:
Entity Type:
Entity Type Label: ASCM
Entity Type Definition: Representation of Alberta Survey Control Markers from the MASCOT database.
Entity Type Definition Source: MASCOT
Distribution Information:
Distributor:
Contact Information:
Contact Organization Primary:
Contact Organization: Service Alberta, Government of Alberta
Contact Position: Land Titles, SPIN 2
Contact Instructions: Use Citation Information Online Linkage within this metadata record.
Resource Description: Geographic Services
Metadata Reference Information:
Metadata Date: 20100120
Metadata Contact:
Contact Information:
Contact Person Primary:
Contact Organization: Alberta Environment and Parks, Government of Alberta
Hours: 08:15 to 16:30 Monday to Friday
Contact Electronic Mail Address: AEP.GDAMetadata@gov.ab.ca
Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata

ESRI Metadata

Published Document ID: {7861DD5A-DB08-44A1-B06F-8F551BB5069F}
Modification Date: 20150624
Modification Time: 09440700
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