Control Points are locations with known coordinates in a defined geodetic spatial reference system and reported at a known level of accuracy. A further distinction can be drawn between geodetic or government control monuments (whose co-ordinates and other properties are recorded in the Province’s GeoNetBC control database) versus various forms of Survey control point (which have coordinates derived by individual surveyors, as part of a specific project, and which are only tracked within the PMBC database).
The following table contains the Control Point attributes and descriptions.
| Attribute Name | Description |
|---|---|
| GlobalID | Unique global identifier for the feature Values: System-generated |
| Name | Unique identifier of a geodetic control monument or georeferenced point. Values: For geodetic control or vertical benchmarks, this is the GCM number from GeoNetBC. For control points received through surveyor submissions, it is a combination of Plan Number and a Description of the marker. Notes: Other types of control point (i.e. GeoBC or field cadastral ties) are generally identified with a standard prefix (‘P’, ‘F’, etc.) |
| TabletMarking | Identifier of a geodetic control point or vertical benchmarks as stamped on cap in field and recorded in GeoNetBC. Values: Free text field (maybe NULL) Notes: This is the description recorded in a survey plan. |
| HorizontalClass | The Horizontal Class field within the GeoNetBC Control database Values: Integrated Notes: More information can be found at GeoNetBC System Screen Generated Reports |
| Type | Describes the control point subtype Values: See Control Type domain for more details. |
| PointID | Corresponding fabric point ID if available
|
| SurveyDate | The date the control point was surveyed/established. Values: DD/MM/YYYY Notes: Comes from source, either as the date of the last Coordinate revision (from the GeoNetBC database) or as the date a Field survey was completed. |
| Active | True if control point is active Values: 0 (Inactive) or 1 (Active) Notes: If true, control point has been associated to the fabric point referenced in the Name field. A control point needs to be active to be used in the fabric adjustment. |
| E | X-Coordinate of the point feature class in BC Albers Values: System-generated Notes: Spatial coordinates of the ArcGIS Point feature class, not the permanent coordinates of the Control Point itself. |
| N | Y-coordinate of the point feature class in BC Albers Values: System-generated Notes: Spatial coordinates of the ArcGIS Point feature class, not the permanent coordinates of the Control Point itself. |
| Z | Height of the fabric point in metres above mean sea level Notes: Refer to the ‘AccuracyZ’ and ‘ElevationClass’ fields to understand how the ‘Z’ value was derived and the absolute positional accuracy of the elevation. |
| EAccuracy | Horizontal accuracy of the Control. A statistical estimate of the likelihood the reported coordinates are close to true location of the measured point. Values: E-coordinate accuracy at 95% confidence level in metres Notes: derived from the Standard Deviation in Longitude recorded in GeoNetBC; field only applies for geodetic control points. |
| NAccuracy | Horizontal accuracy of the Control. A statistical estimate of the likelihood the reported coordinates are close to true location of the measured point. Values: N-coordinate accuracy at 95% confidence level in metres Notes: derived from the Standard Deviation in Latitude recorded in GeoNetBC, field only applies for geodetic control points. |
| ZAccuracy | Z-coordinate (elevation) accuracy at 95% confidence level Values: in Metres Notes: Generally derived from metadata provided by a Surveyor during submission. A value of ‘10’ indicates that the elevation was estimated from a Digital Elevation Model and not surveyed. |
| OriginalSR | Defines the Spatial Reference System used for the original coordinates. Values: See Original SR domain for more details. |
| OriginalRealization | Defines the realization, datum, and version used for the original coordinates. Values: See Original Realization domain for more details. |
| SurveyMethod | The type of survey used to measure original coordinates of a control point. Values: Free text field Notes: If the survey plan type = “Survey” this will be populated from metadata by a Surveyor during submission. It will be the same as the ‘Georeferencing Method’ field of the survey plan that created the control. |
| PlanNumber | The name of the survey plan that created the control. Notes: If the survey plan type = “Survey” this will be populated from metadata by a Surveyor during submission. |
| CreatedDate | Date when control point was entered in the fabric. Values: System-generated Notes: DD/MM/YYYY |
| ModifiedDate | Last date the control point record was modified in PMBC. Values: System-generated Notes: DD/MM/YYYY |
| Condition | Tracks the physical condition of a geodetic control point, as recorded in GeoNetBC. Values: GOOD, ANOMALOUS, DESTROYED Notes: ANOMALOUS indicates that the recorded coordinates are suspect and do not fit with the surrounding Control network. |
| OriginalX | The X coordinate in the original Spatial Reference System. Values: Easting in a UTM NAD83 CSRS spatial reference Notes: Surveyed X-Coordinate (optional) provided by Land Surveyors during submissions or from published values in GeoNetBC. |
| OriginalY | The Y coordinate in the original Spatial Reference System. Values: Northing in a UTM NAD83 CSRS spatial reference Notes: Surveyed Y-Coordinate (optional) provided by Land Surveyors during submissions or from published values in GeoNetBC. |
| OriginalZ | The surveyed orthometric height (elevation) provided by Land Surveyors during submissions or from published values in GeoNetBC. Values: Metres above mean sea level Notes: The vertical datum is not tracked by PMBC. Please refer to source (GeoNetBC or survey plan) for more details on the vertical datum used. |
| QualityClass | A record of the reliability of the published coordinates of a geodetic control point. From the GeoNetBC database. Values: A, B, C, D, and E. Notes: Class A is “very good”, Class B is “good”, Class C is “poor” and Class D is “very poor”. Class E means that the class is unknown, and it could be any of A to D. |
| OriginalEpoch | Defines the epoch for the datum realization. Values: See Original Epoch domain for more details. Notes: The values are for current standard BC realizations. |
| CombinedScaleFactor | Describes the ratio between Ground distances and projected UTM Grid Distances, at the control point location. Notes: For control points = “Survey” this is populated from the surveyor submission metadata and is an average value for the plan. |
| Description | A general description of the physical location and/or appearance of a control point. Values: Free text field Notes: For geodetic control points or vertical benchmarks, this is the Marker Location record from GeoNetBC. For Survey control, a general description of marker type provided by the Surveyor. For CAD Tie, this identifies which parcel corner was tied by the surveyor. |
| Shape | Contains geometry of the feature in the requested Spatial Reference. Values: Point geometry Notes: This is the geometry for the projected control point feature in the integrated parcel fabric and not the underlying component, ground based survey dimensions. |
| Error | Horizontal accuracy of the Control - A statistical estimate of the likelihood the reported coordinates are close to true location of the measured point. Values: This is the semi-major axis of the error ellipse at a 95% confidence level (in metres). Notes: This field only applies for non-geodetic control points. Populated from the surveyor submission metadata. Surveyors calculate this value from GNSS observation. It is the same value labelled in a Survey Plan as ‘Estimated Horizontal Positional Accuracy’. |
| ErrorMinor | Horizontal accuracy of the Control - A statistical estimate of the likelihood the reported coordinates are close to true location of the measured point. Values: This is the semi-minor axis of the error ellipse at a 95% confidence level (in metres). Notes: This field only applies for non-geodetic control points. Populated from the surveyor submission metadata. See Error field for details. |
| ErrorAngle | Horizontal accuracy of the Control - A statistical estimate of the likelihood the reported coordinates are close to true location of the measured point. Values: Azimuth of semi-major axis of error ellipse Notes: This field only applies for non-geodetic control points. Populated from the surveyor submission metadata. See Error field for details. |
| SurveyType | The survey methodology used to measure coordinates for a control point. Values: See Control Survey Type domain for more details. |
In This Section
Introducing an improved ParcelMap BC
An upgraded version of ParcelMap BC has been released featuring a new layout, easier navigation, direct integration with related search services including plan and title applications and access to enhanced map capabilities and features. To learn more about the upgraded version of ParcelMap BC, please see ParcelMap BC New.
The classic version of ParcelMap BC will be available in parallel, until it is retired later this fall. Look for ParcelMap BC classic and ParcelMap BC new in your LTSA account menu options.