East Anglia ONE Offshore Windfarm Generation Assets Monitoring Plan


September, 2016


3.1.1.4 Methodology 36.


This section details the main elements of the high resolution digital still survey methodology to be delivered for the pre- construction aerial surveys of EA ONE in relation to the flight and image acquisition parameters. The survey will be undertaken by APEM Ltd.


37. In summary, the main elements of the flights and image acquisition are:


• Survey flight height of ~1,350 ft - in excess of the safe minimum clearance distance of 500 ft from the tip of the turbines. • Flights occur in conditions that follow published guidance. • Image resolution at 2 cm ground surface distance (GSD) providing very high rates of species identification. • Image acquisition as digital still images using camera system Shearwater II. • Geo-referencing of data. • Detailed attributes collected for each bird including age, sex, behaviour (sitting, flying), flight height and flight direction. • Detailed attributes collected for each survey including weather, sea state, visibility and shipping.


The following sections provide further detail on individual aspects of the methodology. 3.1.1.4.1 Survey flight height


38.


EA ONE survey flights will take place at a height of ca. 1,350 ft to avoid disturbance to birds (and marine megafauna). Surveying at this altitude allows for safe collection of data with no change in methodology and altitude from baseline to post- construction monitoring, as the aircraft will fly far in excess of the minimum clearance distance of 500 ft from the tip of the largest known turbines.


3.1.1.4.2 Flight conditions 39.


The minimum weather criteria for conducting an offshore aerial survey include: visibility greater than 7 km, cloud base above survey altitude, low wind speed, and sea state 4 (moderate) as a maximum.


40.


On days with little cloud, surveying will be avoided for approximately two hours around midday to minimise the risk of collecting images with glare which makes finding and subsequently identifying the birds (and marine megafauna) recorded in the images more difficult. An on board camera technician will continuously monitor images collected and if they cease to be of a sufficient quality image acquisition ceases until suitable conditions return.


3.1.1.4.3 Image resolution 41.


The Shearwater II image acquisition system will be equipped with a camera and sensor system, set up to acquire and save a series of Ultra High Resolution digital still images. The images will be captured at a 2 cm ground surface distance (GSD) resolution. At this resolution it is possible to identify the large majority of seabirds (and marine megafauna) to species level while delivering high coverage and causing no or minimal disturbance.


3.1.1.4.4 Geo-referencing 42.


All spatial data will be geo-referenced to WGS 84 UTM 31N projection. Information derived from the imagery will be held in the industry standard ESRI shapefile format. The spatial datasets contain information on all of the digitised records.


3.1.1.4.5 Collection of relevant information from images 43.


The following information will be recorded for each survey where possible, consistent with Camphuysen & Garthe (2001) and Thaxter and Burton (2009):


• Observation date; • Observation time; • Locations of images and species (latitude and longitude WGS84 UTM31N); • Species (or group) ID; • Number of individuals; • Age and sex (where possible); • Behaviour (sitting, flying); • Flight height; • Flight direction; and • Shipping observations.


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