The advent of aerial digital surveys of marine wildlife in Germany: a review of current experience at IfAÖ Dr Tim Coppack Alexander Weidauer Werner Piper Institut für Angewandte Ökosystemforschung GmbH Rostock & Hamburg
A brief history Developments in UK und DK since 2007 HiDef Aerial Surveying Ltd Mellor et al. 2007 Danish National Environment Research Institute (NERI) Groom et al. 2007 APEM Ltd Bradley et al. 2009 2012 Review, University of St. Andrews Buckland et al. 2012 2012 Development in Germany since 2010 IfAÖ/Univ. Rostock Kulemeyer et al. 2011 (pilot study) since 2012: national research programme - IfAÖ/Univ. Rostock
Pilot Study 2010 Outer Bay of Wismar (EU SPA) parallel visual and digital census - identical transect design - time lag between surveys: 2 h - total transect length: 100 km flight elevations - Digital survey: 200 m - Visual survey: 76 m digital aerial survey - 415 georeferecnes images - sensor resolution: 40 Mpixel - ground resolution: 2.6 cm Kulemeyer C, Schulz A, Weidauer A, Röhrbein V, Schleicher K; Foy T, Grenzdörffer G & Coppack T 2011a: Georeferenzierte Digitalfotografie zur objektiven und reproduzierbaren Quantifizierung von Rastvögeln auf See,- Vogelwarte 49, 2011: 105 110.
Pilot Study 2010 Outer Bay of Wismar (EU SPA) Eider Scoters Divers Long-tailed Duck Kulemeyer C, Schulz A, Weidauer A, Röhrbein V, Schleicher K; Foy T, Grenzdörffer G & Coppack T 2011a: Georeferenzierte Digitalfotografie zur objektiven und reproduzierbaren Quantifizierung von Rastvögeln auf See,- Vogelwarte 49, 2011: 105 110.
Pilot Study 2010 Eider Kulemeyer C, Schulz A, Weidauer A, Röhrbein V, Schleicher K; Foy T, Grenzdörffer G & Coppack T 2011a: Georeferenzierte Digitalfotografie zur objektiven und reproduzierbaren Quantifizierung von Rastvögeln auf See,- Vogelwarte 49, 2011: 105 110.
Pilot Study 2010 Significant deviations between outcome of parallel visual and digital survey deviation possible cause estimation error estimation error estimation error flushing Kulemeyer C, Schulz A, Weidauer A, Röhrbein V, Schleicher K; Foy T, Grenzdörffer G & Coppack T 2011a: Georeferenzierte Digitalfotografie zur objektiven und reproduzierbaren Quantifizierung von Rastvögeln auf See,- Vogelwarte 49, 2011: 105 110.
Are we limited by manpower or technology?
Prototype set-up purpose-assembled hard ware solution made up of standard components off the shelf Camera unit: IXA180 PhaseOne
Digital Aerial Imaging System by IfAÖ (DAISI) cross-eyed DAISI 2 x IXA180 PhaseOne sensor field 10320x7752 cells with 5.2 Micron resolution exposure time 1/1600-1/1000 aperture 3.5 sensitivity ISO 100/200 Forward Motion Compensation (FMC) lens focal length (2 cm ground resolution) 87mm / 350 m flight height 110mm / 425 m flight height (current configuration) 150 mm / 575 m flight height
Image Acquisition 425 m flight height not only HSE, reduction of disturbance of sensitive species and commpromise concerning lower clowd level Ground resolution (Ground Sampling Distance, GSD) 2 cm Flight speed (Partenavia P68C) 180 km/h (100 kn) Oversampling for glare compensation, critical stall speed due to tail wind at 4 Bft Operation time 6-8 h limited by day-length and weather in winter, Positioning accuracy <30 m, managed by Software AeroTopol (GGS Speyer) Transect orientation N-S to compensate for glare
Image pre-processing import of raw data into Capture One Export as 16 bit RGB-TIFF import of meta data such as motion compensation, exposure time (1/1600 or 1/1250), sensitivity(iso 200), aperture number (3,5) raw data acquisition images, meta data, positioning information import of GPS and flight platform data generated by flight management software AeroTopol georeferencing of images using the coordinate systems UTM32 / UTM 33 block-based partitioning of image pyramids for high data throughput resampling of image files to a unit of 2x2cm to compensate fluctuations in flight height and panorama error (1.8 2.25 cm) georeferences image data base with defined ground resolution and adjusted brightness and contrast
Hardware infrastructure for image storage and analysis 2 computer centres with a total storage capacity of 108 TByte 2 fast processing computers for image processing (georeferencing) with 32 cores und 128 GByte RAM per work station 4 advanced graphic work stations for ID und QA in a high-speed ethernet with 10GByte/s 12 graphic work stations for pre-screeing of images Redundant data back-up on approx. 20 USB 3.0 4 Tbyte discs
Visual pre-screening Application of a purpose-programmed, GISbased software tool for visual screening and geo-referencing of biological signals Further analysis in cooperation with Univ. Aarhus and APEM: a)for Univ. Aarhus visual screening of 10% of all images per survey b) for APEM pre-screening and sorting of complete sets of images (positive vs. empty images)
Graphical user interface for pre-screening app
Graphical user interface for pre-screening app Harbour porpoises
Graphical user interface for pre-screening app Gannet
Identification of species Who is the expert? Do we need a new identification guide?
Identification of species elevation: 425 m, ground resolution: 2 cm Heringgull (Larus argentatus)
Identification of species elevation: 425 m, ground resolution: 2 cm Greater Black-backed Gull (Larus marinus) Common Gull (Larus canus)
Identification of species elevation: 425 m, ground resolution: 2 cm Fulmar (Fulmarus glacialis) Kittiwake (Rissa tridactyla) Black-headed Gull (Larus ridibundus) Littel Gull (Larus minutus)
Identification of species elevation: 425 m, ground resolution: 2 cm Guillemot (Uria aalge) Razorbill (Alca torda) Slavonian Greebe (Podiceps auritus) Northern Gannet (Morus bassanus) Common Tern (Sterna hirundo) Arctic Tern (Sterna paradisea)
Identification of species elevation: 425 m, ground resolution: 2 cm Divers (Gavia spec.)
Identification of species elevation: 425 m, ground resolution: 2 cm Common Eider (Somateria mollissima)
Identification of species elevation: 425 m, ground resolution: 2 cm Long-tailed Duck (Clangula hyemalis)
Identification of species elevation: 425 m, ground resolution: 2 cm Common Scoter (Melanitta nigra)
Size matters but is relative Skua spec. Kittiwake
Wind farm project overview (October 2014) IfAÖ/APEM/Aarhus IfAÖ/Aarhus IfAÖ/Aarhus IfAÖ/APEM
Wind farm project overview (October 2014) project (number of surveys) APEM COWI / Univ. Aarhus DAISI / Univ. Aarhus Windanker (3) Wikinger (1) *DanTysk/SB (4) EnBW Baltic 2 (7) Global Tech 1 (5+1) DanTysk/SB (3+1) project phase planning / *construction construction construction camera typ /-model survey design digital ortho-photography, various cameras, e.g. Leika RCD 30 grid design (Windanker/Wikinger) transect design 0-10% image overlap study area [km²] depending on project 2300-3300 km² transect width [km] grid design 1*0,66 km; transect design 3 km; since 2014 4 km digital ortho-photography Vexel transect design 60% image overlap 900-1000 km² yet higher coverage (21%) 2 km 4 km digital ortho-photography Phase-One tandem transect design 30-40% image overlap depending on project 2150-3300 km² fight duration [d] several days 1 d 1 d (6-8 h on effort) flight elevation [m] ca. 400 ca. 475 ca. 425 ground resolution [cm] 3 cm 3 cm 2 cm image size [m] (footprint) depending on camera 310*112 / 269*201 / 222*168 519*393 double image 412*155 single image 206*155 strip width [m] 269-424 m 519 m 412 m covered area [km²] 231-283 km² 155-187 km² 215-330 km² percetage of study area 8-10 % 17-21% 10-12 % n images per survey 3300-6200 3100 5000-8000 double images
Example survey 1 Global Tech 1, German North Sea Same survey design Two parallel Phase One cameras 10,034 images Total coverage 166.6 Km 2 Avg. Image area 0.016 Km 2 0 12,5 25 50 Kilometers 0 0,125 0,25 0,5 Kilometers 0 0,5 1 2 Kilometers
Example survey 1 Global Tech 1, German North Sea Fulmar (left) and Kittiwake adult (right)
Example survey 2
Example survey 2
Calculation of grid densities Example survey 2
Calculation of grid densities Example survey 2
Recommendations Optimize the sampling design! reduce glare at sensor level fly safe under calm conditions reduce the net amount of images and time needed for analysis by concentrating study areas to relevant areas
The problem of glare and EW-flight orientation loss of images through glare despite overlap
The problem of the sampling design
Scientific Outreach Master thesis U. Steffen
Scientific Outreach Ongoing research: simulation of different sampling designs km km Transect design Grid design Master thesis U. Steffen
Kittiwake Seal (spec.) Lesser Black-backed Harbour porpoise Little Gull