Documenting Mackenzie Inuit Architecture Using 3 D Laser

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning Peter C. Dawson, Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Richard M. Levy, Faculty of Environmental Design, University of Calgary, 2500 University Dr. NW. Calgary, AB T 2 N 1 N 4 Charles Arnold, Prince of Wales Northern Heritage Center, Yellowknife, NWT Gerald Oetelaar, Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Dominic Lacroix. Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Dawson, Levy, Arnold, Oetelaar, Lacroix 1

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Introduction – Architectural variability often reflects social processes. – The transition from single to double to triple platform houses in Mackenzie Delta may indicate changes in household organization. – However, the study of the meaning behind these architectural transitions hindered by: • Variation in how accuracy Inuvialuit architecture has been documented by archaeologists over the past 100 years. • The destruction of house ruins by the erosion of archaeological sites on the Beaufort sea coast, and East channel of the Mackenzie River. Dawson, Levy, Arnold, Oetelaar, Lacroix 2

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Goal – Laser scanning provides a means of rapidly capturing architectural information at a levels of detail that may allow us to explore the relationship between house form and culture in Inuvialuit society. – Demonstration: Laser scanning can be used for the reconstruction virtual 3 D models of Inuit Sod Houses Dawson, Levy, Arnold, Oetelaar, Lacroix 3

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • • • Location – Pond Site (Ni. Ts-2). – Several clusters of house depressions Cultural Affiliation – Inuvialuit - regional groups of ancestral Inuvialuit Chronology – Occupied since 1300 AD Dawson, Levy, Arnold, Oetelaar, Lacroix 4

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Previous work – Prince of Wales Northern Heritage Centre conducted excavations at two of the house depressions at the Pond Site in 1989 – In 2002 the Prince of Wales Northern Heritage Centre returned briefly to the Pond site in order to test whether ground penetrating radar was effective in detecting subsurface archaeological features in permafrost environments. Dawson, Levy, Arnold, Oetelaar, Lacroix 5

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Previous Work • Summer of 2007, a laser scanner was used to record the excavation of two Inuit Sod houses located in the Mackenzie Delta, NWT Ni. Ts-2 is located on the west shore of Richards Island at 69 o 20. 6’N and 134 o 03. 3’W Dawson, Levy, Arnold, Oetelaar, Lacroix Towards the mouth of the East Channel of the Mackenzie River 6

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Why use a laser scanner to capture data – Challenges • Expense • Logistics • Cost of processing – Opportunities • Complete record • Baseline for 3 D construction in a CAD environment Dawson, Levy, Arnold, Oetelaar, Lacroix 7

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Laser Scanner Selection – Pulse – Time of Flight • Resolution 6 -10 mm – Point accuracy vs model space • Range – 50 to 400 m. • Field of View – 360 horizontal – 270 vertical • Pts. per second – 5000 to 500, 000 • Cost HDS 6000 – $100, 000 US + Dawson, Levy, Arnold, Oetelaar, Lacroix CYRAX 2 8

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Issues: – Laser Scanner Selection • Modulating Light – Resolution – 3 mm at 20 m – Range –. 6 to 20 m – Field of View » 360 horizontal » 320 vertical – Pts. per second - 120, 000 pts – Color – 24 bit – Cost – $100, 000 US Dawson, Levy, Arnold, Oetelaar, Lacroix 9

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Laser Scanner Selection – Phase • Resolution -. 03 mm (Z) • Range -. 6 to 2. 5 m • Field of View: Lens dependent – Telephoto Lens: 111 x 84 x 40 mm to 460 x 350 x 130 mm – Mid Lens: 196 x 153 x 70 mm to 830 x 622 x 220 mm – Wide Lens: 355 x 266 x 92 mm to 1200 x 903 x 400 mm • Pts. per second – 300, 000 • Color - 24 bit 640 x 480 • Cost - $40, 000+ Dawson, Levy, Arnold, Oetelaar, Lacroix 10

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • • • Choice of Scanner – Two Scanners vs. One • General Survey vs. High Level of Detail Decision: Minolta Vivid 910 – Point accuracy vs. Model accuracy • . 03 mm vs. Time of flight +/- . 6 mm Acquisition time- 300, 000 pts/sec Weight 25 lbs Price – used unit within budget Dawson, Levy, Arnold, Oetelaar, Lacroix 11

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Issues: – Logistics • Transport – Helicopter and quad • Weather – Temperature and humidity » 10 to 40 C » 65% or less – Lighting conditions • Electric Power – Generator and UPS – Time Constraints • One day per site Dawson, Levy, Arnold, Oetelaar, Lacroix 12

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Laser Scanning – Occlusion House 4 Dawson, Levy, Arnold, Oetelaar, Lacroix 13

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Laser Scanning – Overlap • Targets • Orphaned Polyfaces Dawson, Levy, Arnold, Oetelaar, Lacroix House 3 14

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Laser Scanning – Field of View Telephoto 111 x 84 x 40 mm 460 x 350 x 130 mm Mid Lens 196 x 153 x 70 mm 830 x 622 x 220 mm Wide Angle 355 x 266 x 92 mm 1200 x 903 x 400 mm Dawson, Levy, Arnold, Oetelaar, Lacroix House 3 15

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Laser Scanning – Field of View Telephoto – Setup Time 111 x 84 x 40 mm 460 x 350 x 130 mm Mid Lens 196 x 153 x 70 mm 830 x 622 x 220 mm Wide Angle 355 x 266 x 92 mm 1200 x 903 x 400 mm Dawson, Levy, Arnold, Oetelaar, Lacroix House 3 16

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Color – From digital imagery vs. scanner • Issues – Light levels – Reflectance » Soil moisture – Resolution – Color Depth Dawson, Levy, Arnold, Oetelaar, Lacroix 17

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Collection: Color – From digital imagery vs. scanner • Issues – Light levels – Reflectance » Soil moisture – Resolution – Color Depth Dawson, Levy, Arnold, Oetelaar, Lacroix 18

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Data Processing – Polyworks 10. 1 • Point Cloud – 90, 000 points in two days – Mesh files • From points to polyfaces Dawson, Levy, Arnold, Oetelaar, Lacroix 19

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning I Output formats: CDM Polytrans Input Format: OBJ Output Forma: 3 DS 3 d Studio Input Format: OBJ Output Format: MAX Dawson, Levy, Arnold, Oetelaar, Lacroix Media Products: AVI, MOV, QTVR, Tif, JPG Media/ VR VR: Virtools 20

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning I Output formats: CDM Polytrans Input Format: OBJ Output Forma: 3 DS 3 d Studio Input Format: OBJ Output Format: MAX Dawson, Levy, Arnold, Oetelaar, Lacroix Media Products: AVI, MOV, QTVR, Tif, JPG Media/ VR VR: Virtools 21

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Recommendations – Two scanners • General survey work – Time of flight for general survey work • Detail scanning – Triangulation scanner (Minolta Vivid 910) – Registration • Targets - Improve the legibility of the 3 D targets with less reflective targets Dawson, Levy, Arnold, Oetelaar, Lacroix 22

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Recommendations – Control light levels • Portable Structure • Increase lighting levels with daylight flouresent – Control the distance from scanner to object • Rail system for mounting the scanner • Maintain constant distance to object – Dawson, Levy, Arnold, Oetelaar, Lacroix 23

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning • Conclusions – Laser scanning offers a means of rapidly documenting Inuvialuit architecture at high levels of resolution, and in a standardized fashion. – Our research indicates that the use of laser scanning technology is possible in remote environments like the Canadian Arctic. – Documenting Inuvialuit sod houses at high resolutions will enable archaeologists to examine the possible social and ideological significance of variability in circumpolar architecture Dawson, Levy, Arnold, Oetelaar, Lacroix 24

Documenting Mackenzie Inuit Architecture Using 3 D Laser Scanning Peter C. Dawson, Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Richard M. Levy, Faculty of Environmental Design, University of Calgary, 2500 University Dr. NW. Calgary, AB T 2 N 1 N 4 Charles Arnold, Prince of Wales Northern Heritage Center, Yellowknife, NWT Gerald Oetelaar, Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Dominic Lacroix. Department of Archaeology, University of Calgary, 2500 University Dr. NW. Calgary, AB. T 2 N 1 N 4 Dawson, Levy, Arnold, Oetelaar, Lacroix House 4 25