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Project status ? On top of it, know/have exactly what I need
Pretty sure what I want to do, need to acquire data Have some thoughts, but not too sure on area/data Still scanning my memory banks Project ? …. Are you talking to me ? Data: BC – we have much landsat already ( ) Landsat: global archive available (1972/82 – 2010) SPOT : online for most of Canada ( )
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Jackpine Creek -> 2008
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Jackpine Creek 2004 (Albers) ScienceDaily (Apr
Jackpine Creek (Albers) ScienceDaily (Apr. 4, 2011) — A University of Alberta-led research team has determined that the mountain pine beetle has invaded jack pine forests in Alberta,
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LiDAR = Light Detection And Ranging ...also known as LASER altimetry
.. is an increasingly common form of active remote sensing - It is commonly used to create high resolution DEMs - 1 foot or <1 metre (airborne) Objects reflect more in UV-visible- NIR (than microwaves) and enable higher resolution mapping. SONAR SOund NAvigation and Ranging : sound propagation for communication/ navigation SODAR: SOnic Detection And Ranging : sound propagation upwards (atmospheric)
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What is LiDAR ? Controlled bursts of LASER (Light Amplification by Stimulated Emission of Radiation) Distance to object given by TIME requires 3 units: laser emitter/receiver, GPS, IMU (Inertial measurement unit) Used in 60s-70s for scanlines, feasible for images with development of GPS (1990s) now widely available
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Range finding LiDAR for topographic mapping
Laser bursts are emitted at these wavelengths: (why these ??? *) 355 nm (UV) 532 nm (green) 1064 nm (Near IR) * [Taser guns are at 650 nm ; phasers at 350nm ] Unaffected by clouds above (unlike photos / airborne scanning) .. why?
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LiDAR – 1064 nm, 532nm, 355nm - why those wavelengths ?
Lasers produce light the same way as a neon sign – a substance is stimulated to an excited state, causing the release of extra energy as a photon of light. Nd:YAG (neodymium-doped yttrium aluminium garnet) is a crystal that is used as a lasing medium for solid-state lasers. It emits at a wavelength of 1064 nm. According to the Planck-Einstein equation: Where h= Planck’s constant, and c = the speed of light, halving the wavelength, has the effect of doubling the energy released, and one-third the wavelength (355) triples the energy (= the second and third harmonics) … Not solved by googling or LiDAR marketing companies Solved by Patrick Daley, GEOG432 (Fall 2009)
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LiDAR applications: detailed DEMs
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LiDAR applications: detailed DEMs
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Volume estimation: Ground Zero
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Sea Level rise from ICe in Svalbard (SLICES): 20 m interpolated model of Slakbreen
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Returns give distance (hence heights) for multiple levels:
the only remote sensing technique able to distinguish between multiple ground layers
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Vegetation: Tree Canopy Height
Air photo Vegetation surface DSM Bald Earth Model (BEM)
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Aleza Lake Research Forest
Oldest research forest in BC, jointly operated by UBC and UNBC 60km north-east of Prince George
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Canopy Height = Canopy Surface – Bare Earth
Canopy Surface Model Each cell in a canopy surface model details the elevation of the highest feature within that cell Height is more practical than elevation for describing vegetation Canopy Height = Canopy Surface – Bare Earth
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Canopy Height Model
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Canopy Surface Model
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Tree Stem Maps Individual tree crowns are discernable from the Canopy Height Model so we developed a tree finding algorithm to identify tree stem locations
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Vegetation Data Products
LiDAR Data – tree stems
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Tree Stems (displayed by tree height)
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Tree Stems (displayed by crown shape)
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Forests for the World orthophoto
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City 1 metre DEM (from 1m contours)
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LiDAR Forests for the World, 2009
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UNBC / Cranbrook Hill LiDAR 2009
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LiDAR Platforms Airborne since 1970s e.g. Optech (Ottawa) and NorthWest Geo (Calgary) Many others …. ICESat (Jan 2003): Geoscience Laser Altimeter System (GLAS): 66m 'footprint' and 10cm vertical resolution, designed for polar icecaps CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation ALADIN Wind LiDAR
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LiDAR summary Present drawbacks: (all reducing with technology increase) The high cost of collecting lidar High data volume Steep learning curve in research and understanding (involving utilizing the entire point cloud) Advantages: Very high resolution DEM for many applications Multi-layer data for forestry and ecosystems Increasing data supply – some free download Increasing conference content in GIS/RS/Cartography Many online resources e.g. : USGS: BC CARMS:
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Stonehenge http://www.youtube.com/watch?v=pzYUx4l80m8
Stonehenge
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