Model Setup IDMVol 3: Case Studies

Gateway to Melbourne, Australia. Source: Fender Katsalidis, Architects

Version 0.3 • 7 June 2017

Case Studies

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Contents1 Case Study Outline 1

1.1 The Objective 1

1.2 Your Project Context and Team 1

1.3 A Representative Survey Document 1

1.4 Example 1: 2D Helmert Transformation 1

1.5 Example 2: 2D Helmert Transformation. 2

2 Linear Assets - Alignment 33 Appendix 1: National Land Boundary 4

3.1 Australia - AU 4

3.2 CA 5

3.3 CH 5

3.4 DE 5

3.5 ES 5

3.6 FI 5

3.7 HU 5

3.8 JP 5

3.9 NO?? 5

3.10 NZ 5

3.11 UK 5

3.12 US 5

4 Appendix 2: Helmert Transformation 6

FiguresFigure 1: Site in the map grid coordinate system (grid north is up the page) 1

Figure 2: Site in the local grid coordinate system (Y is up the page) 2

Figure 3: The resultant converted data tested in a Map. 3

Figure 4:  A New South Wales (NSW), Australia state Cadastral Title document 4

Figure 5:  Norwegian... 5

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Case Studies

7 Jun 2017 buildingSMART Australasia page ii

Version History

Version0.10.20.3

Date5 May 20179 May 20177 June 2017

ScopeFirst draftGeneral amendmentsRevised title Vol 3: Case Studies

ByJMiJMiJMi

Case Studies

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1 Case Study Outline1.1 The ObjectiveIn the presentation (BuildingSMART Model Setup-ISG Mar 2107.pdf) you’ll see at the end an example of a geo-referenced model. This example is elaborated in detail below.What we are asking case studies to do is to either verify the procedure for an existing project, or undertake the procedure for a new project.In ISG the vendors are starting to implement this (ifcMapConversion etc) subject to some tweaking as outlined in the Mtg 24 notes.The key task is to check the geo-referencing procedure and in your (their) application. Does the vendor need to augment the IFC interface etc or additional attributes displayed for location etc?

1.2 Your Project Context and Team What is the nature of the development, asset type, BIM scope etc.Who are your project team members: Client, Designers, Surveyor, Engineers, Builders etc. and how is the survey/map data used (or could be used).Is this an existing project or a new one?

1.3 A Representative Survey DocumentIn essence can you give an example for your location (Helsinki, Montreal, Tokyo, Madrid…)? And if there is an infrastructure example - excellent!What are your national protocols for Land Ownership? In Appendix 2 we are collecting national land boundary methods

1.4 Example 1: 2D Helmert TransformationBased on a similar survey document to that above, in this example two reference points (Ref1 and Ref2) have been defined at opposite ends of the site. The points have been connected to local survey control by a Land Surveyor. The resulting coordinates of the reference points in the national map grid coordinate system (MGA -Map Grid of Australia, Zone 56) are:Ref1 E = 333,780.622 N = 6,246,775.891 H = 97.457Ref2 E = 333,906.644 N = 6,246,834.938 H = 98.291

where E is Easting, N is Northing and H is the orthometric height (AHD - Australian Height Datum). All values in metres.

Figure 1: Site in the map grid coordinate system (grid north is up the page)

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A local grid coordinate system has been made for the site to reduce the size of the coordinates and to align the site to better fit on paper plans. The resulting coordinates (in metres) of the reference points in the local grid coordinate system are:Ref1 X = 0.000 Y = 0.000 Z = 0.000 Ref2 X = 116.611 Y = 75.960 Z = 0.834

where X, Y, Z represent a right handed Cartesian coordinate system with Z equivalent to up. All values are in metres.

Figure 2: Site in the local grid coordinate system (Y is up the page)

A Helmert transformation can be computed from the coordinates of the two reference points. The parameters of such a transformation are:

X Shift = 333,780.622Y Shift = 6,246,775.891Z Rotation = -7°58'28" Scale = 0.999998

The corresponding ifcMapConversion parameters are:Eastings = 333,780.622Northings = 6,246,775.891OrthogonalHeight = 97.457XAxisAbscissa = 0.990330045XAxisOrdinate = -0.138731399Scale = 0.999998

IfcCoordinateReferenceSystem

IFC Result #21=IFCCOORDINATEREFERENCESYSTEM('EPSG:28356','Zone 56','GDA94','AHD');#22=IFCMAPCONVERSION(#nn,#21,333780.622,6,246,775.891,97.457,0.990330045,-0.138731399,0.999998);

1.5 Example 2: 2D Helmert Transformation.This example is provided by Andreas Geiger of KHH Forschuungszentrum Karlsruhe.

AttributeNameDescriptionGeodeticDatumVerticalDatum

Example 1Map Grid AustraliaZone 56GDA 94AHD

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The test file AC20-FZK-Haus_GeoRef.zip is available here https://bsi-intranet.org/kos/WNetz?art=Folder.show&id=3281).

/* IfcMapConversion *//* EPSG:25832 - ETRS89 / UTM Zone 32N *//* E 458870.063292 *//* N 5438773.629031 */#62= IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model',3,1.00000000000E-5,#59,#60);#66= IFCPROJECT('0lY6P5Ur90TAQnnnI6wtnb',#12,'Projekt-FZK-Haus','Projekt FZK-House create by KHH Forschuungszentrum Karlsruhe',$,$,$,(#62,#374),#49);#100001=IFCCOORDINATEREFERENCESYSTEM('EPSG:25832','UTM Zone 32N','ETRS89',$);#100002=IFCMAPCONVERSION(#62,#100001,458870.063292,5438773.629031,113.7,0.270600445976,0.962691746426,$);

Figure 3: The resultant converted data tested in a Map.

2 Linear Assets - AlignmentIf your project is a linear asset, or has implemented ifcAlignment, then add its context, and describe the master GIS setout.

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3 Appendix 1: National Land Boundary3.1 Australia - AU

Figure 4:  A New South Wales (NSW), Australia state Cadastral Title document

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3.2 CA

3.3 CH

3.4 DE

3.5 ES

3.6 FI

3.7 HU

3.8 JP

3.9 NO??

Figure 5:  Norwegian example (tbc)

3.10 NZ

3.11 UK

3.12 US

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4 Appendix 2: Helmert TransformationThe transformation is applied as follows to convert coordinates from local to map grid:

E = (A * X) - (B * Y) + EastingsN = (B * X) + (A * Y) + NorthingsH = Z + OrthogonalHeight

where A = Scale * cos(Rotation),B = Scale * sin(Rotation), andRotation = atan2(XAxisAbscissa, XAxisOrdinate)