Geomatics Consulting Projects
North Fraser Port Authority
History of North Fraser Mapping and Harbour Headline Control
The harbour headline of the North Fraser was originally defined by description. In 1958 a mapping program was undertaken to define the headline in terms of coordinates relative to a monumented framework.
A classic triangulation network of the control was made. The mapping of the North Fraser was compiled from 1958 aerial photography and control surveys by Underhill & Underhill, completed in 1959. Planimetric detail was scribed from the air photos and this information was combined with an overlay of cadastral survey lines.
Although revisions were made from time to time, the information on the plans became outdated, and the reference monumentation largely destroyed by dyking, and new construction. The plans were at a scale of 1" to 200'. Harbour headline, channel, and control monument coordinates were at ground level to a project specific imperial datum, and expressed in terms of Latitudes and Departures.
In 1979 the Port again contracted U&U to update its mapping. It was determined that a number of improvements should be made to modernize the mapping, and make it more appropriate for the Ports needs. These included:
Metrification
Canada was rapidly making the transition in the metric system whereby all measurements and units of reckoning were being converted to the International System of Units (SI). The old maps of the North Fraser were becoming obsolete because of the change of units, and the changes and developments that had taken place since their production 20 years earlier.
Integrated Survey
By 1979 integrated surveys had become a policy implemented by the Surveys Branch of the Province. At the time, areas of Surrey and Delta had been declared as "Integrated Areas", and Richmond was in the process of setting out its monuments. In time all of the jurisdictions surrounding the North Fraser would become Integrated. The coordinates used in the system would be NAD'27 UTM defined by existing first and second order control (Point Atkinson & Burnaby Mountain).
Traversing with EDM (Electronic Distance Measurement) was used to tie the existing 1959 triangulation to geodetic control. EDM distances were used to strengthen the existing triangulation. A number of monuments were either updated, or replaced.
Orthophotography
Orthophotography was used as the base map with cadastral and Integrated Survey information overlaid. The orthophotography provided for every detail on the original aerial photography to be available rather than only those features chosen to be scribed by Planimetric mapping.
The final mapping was produced in 16 sheets at a scale of 1:2500 metric.
In 1989, following an information system consultant's report which showed that the majority of the Port's data was spatial based, they decided that the logical direction to go was towards digital mapping and GIS. The program involved:
Control Update
Destroyed monuments were replaced and resurveyed. A number of old coordinates were changed to reflect observed displacements.
Digital Cadastral Compilation
The former scribed cadastral overlay was recomputed using coordinate geometry (COGO) for all of the Port's lease surveys. Surrounding Municipal (upland) was compiled from Municipal digital data (when available) or digitized from hardcopy maps.
Digital Mapping
Planimetric features were captured by digital photogrammetric means. These included: improvements on the foreshore (buildings, wharves, piles, dolphins, etc.), vegetation limits, and high water mark.
Orthophotography
New orthophotos were made of each of the 1:2,500 map sheets. No cadastral overlay was generated.
Geographic Information System(GIS)
A GIS was implemented in Terrasoft. The digital cadastral and mapping data formed the graphic side of system. Parcel attribute information was loaded from BC Assessment Authority data, and NFPA leasing information.
Currently the system contains over one hundred viewable features. These include: NFPA river channel features (such as dolphins, pilings, harbour headlines, and channel lines), cadastral features within a 200 metre buffer of the river banks, FREMP (Fraser River Estuary Management Program) data and other environmental and shoreline habitat banks, NFPA leasing information (ie. water lots, log storage areas, and rights-of-way), planimetric mapping features, municipal zoning, and BCAA data.
Nine individual themes have been developed and linked to external attribute databases for query and analysis purposes. A customized menu system has been developed to provide exceptional user "friendliness". Output capabilities include vector pen plotting and DGN and DXF file formats.
In 1996 Underhill worked to rationalize the North Fraser control system the Integrated Survey Areas which had grown up around it. At that time NFPA used NAD'27 and the surrounding jurisdictions had moved to NAD'83.
Data from the 1959 & 1989 surveys, additional GPS positioning, and ties to surrounding Integrated Survey Monuments were used in a GeoLab adjustment to produce NAD'83 coordinates for a framework of NFPA control. These points were used to generate a transformation surface. The surface was used to calculate a grid of Northing and Easting shifts. This grid was used in conjunction with in-house developed software to transform the entire NFPA data set to NAD'83.
NFPA Lease Survey Instructions for British Columbia Land Surveyors
The NFPA harbour headline control is utilized to define the location of the harbour headline. As this control predated the establishment of virtually all Integrated Survey Areas (ISA's) in the Lower Mainland there are obvious differences and distortions in the control fabric relative to these more recent surveys.
After the Province adopted the NAD'83 datum it was decided to migrate the NFPA data to this datum from its original NAD'27 base. The present system is based on the original survey of 1959 with: updates, additions, GPS on selected points, and some ties to surrounding ISA's. Although this resulted in better agreement overall with the surrounding ISA's there are still some local differences (+/- 0.5 metres). The relative accuracy of the control between monuments is 1:5,000 or better, but some monuments have been disturbed from their original locations.
In light of this fact the present harbour headline control monuments must be employed in establishing the location of the harbour headline for surveys within the jurisdiction of NFPA. In the future NFPA will move to CSRS'98 in keeping with the recent adoption of this datum by the Province. At that time the control will be revisited to see if a better fit can be effected.
Lease surveys of North Fraser foreshore should be done in accordance with the Surveyor Generals Instructions for Surveys under the Land Act, with the following additions:
Ties will be made to a minimum of two NFPA Harbour Headline control monuments for the purposes of computing the location of the harbour headline. Note: that the NFPA coordinate system is NAD'83 UTM Zone 10. The definition of the NAD'83 datum in this regard, while consistent overall with the surrounding ISA's, will show localized variations. The relationship between the Harbour Headline (HH) points and the control points is fixed. Computation of the theoretical intersection of the projection of lease boundaries with the HH should consider this fact.
Generalized procedure to determine the location of the Harbour Headline on a NFPA Lease Survey:
- Tie to at least two NFPA control monuments. Confirm that they are in relative agreement.
- Reduce your survey of the upland cadastral framework to grid and compute its position relative to the NFPA control points.
- Project your boundaries to intersect the Harbour Headline chord, or chords, as defined by HH UTM coordinates.
- Produce the ground distances for the intersections.
- Rotate and shift your survey back onto the appropriate ISA system.
- On your plan insure that:
- there are ties between your survey and NFPA control;
- harbour headline points are shown (lines can be foreshortened either side of the survey), with bearing and distances between;
- a table of NFPA coordinates used is shown (control and harbour headline).
Headline and Control Monument Data Requests
Presently data requests for coordinates and monument location sketches are handled by Underhill Geomatics Ltd.
Mapping Data Requests
Mapping data can be requested though the Port. North Fraser Port Authority