Measuring Microhabitat

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Ecological Methodology
LEC-08 Althoff

• Measuring Microhabitat Part II

Digital Images On-the-ground Low-level Aerial
Photography (non-satellite)
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Digital Photographs Advantages over film

• __________ per image
• ________ verification of image taken (if one so
  chooses)
• Time/Date Stamp
• Image Analysis Potential a) during a project
• b) across projects
• _____________________

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VOR Measures - Improvements

• Daubenmire Frame, Robel Pole, and Nudds Board
  ___________________________ imagesthen
  ____________ in the office, not the field, to
  improve accuracyand verify field estimate/record
• Limb et al. 2007 -________________________

Limb, R.F., K.R. Hickman, D.M. Engle, J.E.
Norland, and S.D. Fuhlendorf. 2007.
Digital photography reduced investigator
variation in visual obstruction measurements for
southern tallgrass prairie. Rangeland
Ecology and Management 60548-552.
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Limb et al. 2007

• Used ___ megapixels images (i.e., camera
  resolutionit was 2006-2007)now can easily go to
  ______ megapixel so for same cost of
  improved digital camera equipment
• Compared digital image estimates of VOR to those
  using both Nudds Board and Robel Pole
• Shot digital photo on calm days, with 1 x 1 m
  frame positioned as a backdrop

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Limb et al. 2007
Digital Image
Imported to Adobe Photoshop
Converted to black and white
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Limb et al. 2007

• Adobe PhotoShop used a) software threshold
  function to convert color images to black and
  white images
• Used same threshold setting for all images (128),
  which was often the default setting.
• Used the histogram feature to provide of black
  and white pixels per imageactual measure was
  percent of black pixelsthen used ___________
  ___________________ to compare precision across
  methods

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CV 6.7 Digital 32.1 Nudds 52.2 Robel
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________________________ with the digital
photoapproach (i.e., more idiot proof less
user variability)
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estimation of biomass tighter with the Digital
Image estimate than the Robel Pole
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_________________ __________ with the digital
photo approach
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Low-Level Aerial Photography

• Some early efforts in the late 1960s early
  1970s
• Original efforts used SLR cameras. Very limited
  because usually 24 or 36 images per launch
  restriction
• By _______________, transition occurring from SLR
  cameras to digital cameras a) lighter b)
  lower cost per camera c) lower cost per
  image d) easily can exceed ___ images per
  launch

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Basic System

• 3 basics components a) lift
  platform b) camera platform c)
  on-the-ground platform/controls
• Bigger the lift platform, the bigger the camera
  platform it can support
• Camera platform major weight is the _______
  _______ to power camera, transmitter (video) and
  receiver (signals from ground unit). More
  battery power provides longer launch sessions

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Lift Platforms
BLIMP Helium-filled More stable up to 20 mph
winds
KITE less stable
BALLOON Helium-filled More stable yet up to 30
mph winds
Early efforts
currently moving towards this type
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Lift Platformsnext generation!
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Camera Platform
BATTERIES
PAN TILT adjustments
CAMERA
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Ground Controls
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Challenges -- In the field

• ______________________
• Stay lt _________ (otherwise FAA regs)
• Transporton groundof the lift platform
• Topography (also see analysis)
• _______________ (tree challenges)
• Create _____________________

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Creating Landmarks/GPS points
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Challenges -- Analysis

• Software some off-the-shelf, some very
  expensive (gt3,000 per user) vs. domain-free (0)
  image processing
• What to measure? ______ vs. ____________
• ______________________________rain distortion
  of land surface increases from flat to steep
• ______________.good to rectify photo (i.e.,
  need _____________________in photo and use
  ARCMap, ARCGIS type software for doing this and
  more

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Costs of Low-Level Aerial Photography Systems

• Went from over __________ per system in the late
  1990s to
• Today ___________ with much more capability
• Costs typically less than satellite images
  (although smaller area) and the these systems
  offer more flexibility in scheduling (vs. working
  with government or private satellite operations)

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1 hectare 2.45 acres (100 m x 100 m)