Measuring Microhabitat – Part II Digital Images: On-the-ground Low-level Aerial Photography (non-satellite) FIELD BIOLOGY & METHODOLOGY Fall 2015 Althoff Lecture 16

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 _____________________

VOR Measures - Improvements Daubenmire Frame, Robel Pole, and Nudds Board ___________________________ images…then ____________ in the office, not the field, to improve accuracy…and verify field estimate/record Limb et al ________________________ Limb, R.F., K.R. Hickman, D.M. Engle, J.E. Norland, and S.D. Fuhlendorf Digital photography: reduced investigator variation in visual obstruction measurements for southern tallgrass prairie. Rangeland Ecology and Management 60:

Limb et al Used ___ megapixels images (i.e., camera resolution…it was )…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

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

Limb et al 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 image…actual measure was “percent of black pixels…then used ___________ ___________________ to compare precision across methods

________________________ with the digital photoapproach (i.e., more “idiot proof” = less user variability) CV: 6.7% Digital 32.1% Nudds 52.2% Robel 1

_________________ __________ with the digital photo approach estimation of biomass “tighter” with the Digital Image % estimate than the Robel Pole 2

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

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

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 moving towards this type

Lift Platforms – the latest BALLOON Helium-filled More stable yet up to 30 mph winds Moving from “tethered” to non-tethered equipment ___________ AKA UAV = unmanned aerial vehicle

August 18 - finished Rio WETLANDS expansion July under construction

Camera Platform PAN & TILT adjustments CAMERA BATTERIES

“hobby” DRONE controls FPV = first person view for picture/video control Controller / transmitter of drone

Camera Platform PAN & TILT adjustments CAMERA BATTERIES

Ground Controls

“hobby” DRONE controls FPV = first person view for picture/video control Controller / transmitter of drone

Challenges -- In the field Weather conditions Stay < _____ ft (otherwise FAA regs) Transport—on ground—of the lift platform— for older blimp/balloon system. Now overcome with drone lift platform Topography (also see analysis) Vegetation (“tree” challenges”) –less for drone Create landmarks/GPS points

Creating Landmarks/GPS points

Challenges -- Analysis Software: some off-the-shelf, some very expensive (>$3,000 per user) vs. domain-free ($0) image processing What to measure? “pixels” vs. outline = area Flat vs. gently rolling vs. steep terrain: “distortion” of land surface increases from flat to steep Geo-reference….good to “rectify” photo (i.e., need GPS points/landmarks in photo and use ARCMap, ARCGIS type software for doing this and more

Costs of Low-Level Aerial Photography Systems Went from over ________ per system in the late 1990s to… 3-5 years ago: $3,500 to $7,500 with much more capability…especially the camera options 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) NOW…”hobby” drone out-of-the-box with camera: ______________

1 hectare = 2.45 acres (100 m x 100 m)

Aerial-”time sensitive” images over bluebird boxes

Low-Level Aerial Photography Systems …additional applications Video possible… Survey lakes, ponds, wetlands that are more difficult to access without disturbing wildlife Survey some vertebrate species…but little research yet on “flight vs. freeze” responses Survey terrain difficult to hike/climb/reach Find (and remove?) invasive wildlife species Etc….literally, the sky is _____ limit!