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    Orthoimagery - Annex 1

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    [IS] Á níunda áratug síðustu aldar voru fluglínur fyrir bandarískar loftmyndir frá 1956-1961 (svokallaðar DMA myndir) teiknaðar á níu kort í mælikvarðanum 1:250 000. Fyrsta og síðasta myndnúmerið var skrifað á hverja fluglínu. Nú hafa kortin verið staðsett og fluglínurnar settar á vektor form þar sem númer myndanna kemur fram í eigindum. Í kjölfarið var gagnagrunnurinn (fluglínur og loftmyndir) endurskoðaður. Nýlegar skannanir á öllum DMA myndunum frá Bandaríkjunum voru rýndar og aukaupplýsingum bætt inn í töflur, svo sem dagsetningu ljósmynda, brennivídd linsu og flughæð. Fluglínurnar voru einnig flokkaðar eftir staðsetningu og nálægum dagsetningum í eigindina „svæði“. Svo kölluð brúun (e. interpolation) var framkvæmd á hverri fluglínu þegar þær voru endurskoðaðar. Fyrsta og síðasta ljósmyndin á hverri fluglínu er þekkt, og gengið út frá því að allar myndir milli þeirra væru teknar með reglulegu millibili. Áætluð staðsetningarnákvæmni er +/- 2 km. [EN] The flightlines from the American photographs from 1956-1961 (so called DMA images) were hand-drawn in the 1980s in nine maps in 1:250.000. Each flightline had the first and last image number written on it. These maps were georeferenced and the flightlines were digitized into vectors, writing the image number as attributes. Once this was finished, a revision of the database was made. The recent scans of all the DMA images from USA were inspected, and extra information was added into the table, such as the date of the photographs, the focal lenght and flight height. The flightlines were also grouped by location and nearby dates, into the attribute "area". Once the flightlines were revised, an interpolation was done for each flightline. Since the first and last photograph of each flightline was known, we interpolated each photograph within a flightline assuming that all the images were captured at a regular interval. The expected accuracy of the geolocation is +/- 2 km.

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    The MODIS marine chlorophyll a product provided, similar to SST, is a 4 km global monthly composite based on smaller resolution daily imagery compiled by NASA. The imagery is reliant on clear ocean (free of clouds and ice) so only months from March to October have been provided, as the chlorophyll levels in the Arctic diminish during the winter months, when sea ice is prevalent. The marine chlorophyll a is measured in mg/m3

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    Marine primary productivity is not available from the NASA Ocean Color website. Currently the best product available for marine primary productivity is available through Oregon State University’s Ocean Productivity Project. A monthly global Net Primary Productivity product at 9 km spatial resolution has been selected for this analysis. The algorithm used to create the primary productivity is a Vertically Generalized Production Model (VGPM) created by Behrenfeld and Falkowski (1997). It is a “chlorophyll-based” model that estimates net primary production from chlorophyll using a temperature-dependent description of chlorophyll photosynthetic efficiency (O’Malley 2010). Inputs to the function are chlorophyll, available light, and photosynthetic efficiency.

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    The MODIS Land Surface Temperature (LST) product provided is a monthlycomposite configured on a 0.05° Climate Model Grid (CMG). It includes both daytime andnighttime surface temperatures, taken at 11 um and 4 um (night). This product has beenscaled. To convert the raster values to a Kelvin temperature scale, multiply by a factor of 0.02.

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    The Snow Covered Area product is based on a Normalized Difference Snow Index(NDSI), which is similar to NDVI, but exploits different bands in the equation (Equation 3),namely Green (Band 4) and Short Wavelength Near-infrared (SWNIR, Band 6). It isimportant to note that the Band 6 sensor on MODIS Aqua malfunctioned shortly after launch,so Snow Covered Area from the Aqua sensor is calculated using Bands 3 and 7. This mayintroduce errors in identifying snow in vegetated areas, as the use of Band 7 results in falsesnow detection. For this reason the MODIS Terra product has been provided for the CAFF-system.

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    Loftmyndasjáin er vefsjá með sögulegum loftmyndum og er byggð á loftmyndasafni Landmælinga Íslands sem nær rúmlega 80 ár aftur í tímann. Vefsjáin var hönnuð hjá Landmælingum Íslands í samstarfi við Jarðvísindastofnun HÍ og Fjarkönnunarmiðstöð HÍ. Loftmyndunum sem finna má í vefsjánni (https://www.lmi.is/is/landupplysingar/fjarkonnun/loftmyndasafn) hefur verið safnað úr flugvél, þær skannaðar og breytt í kort. Vefsjáin gefur því fólki færi á að stökkva upp í nokkurs konar ferðatímavél yfir Íslandi og skoða þær breytingar sem orðið hafa á landslagi, t.d. af völdum eldgosa, hopunar jökla eða útbreiðslu plantna, og í þéttbýli síðustu 80 árin. Loftmyndasjáin nýtist við kennslu, rannsóknir og sögu auk þess að svala almennri forvitni. Aðgangur að vefsjánni er öllum opinn og án gjaldtöku.

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    The MODIS Land Cover Type product is created yearly using three landclassification schemes; the International Geosphere Biosphere Programme (IGBP)classification scheme, the Univertiy of Maryland (UMD) classification scheme, and aMODIS-derived Leaf Area Index /Fraction of Photosynthetically Active Radiation(LAI/fPAR) classification scheme (Table 3). The International Geosphere Biosphere Programme (IGBP) identifies seventeenland cover classes, including eleven natural vegetation classes, three non-vegetated landclasses, and three developed land classes. The product provided is derived using the samealgorithm as the 500 m Land Cover Type (MOD12Q1), but is on a 0.05° Climate Model Grid(CMG), that has been clipped to the pan-Arctic extent. The UMD classification scheme issimilar to the IGBP classification scheme, but it excludes the Permanent wetlands,Cropland/Natural vegetation mosaic, and the Snow and ice classes. The LAI/fPARclassification scheme is the smallest of the three, and focuses on forest structure; it only haseleven classes. All three land cover classification schemes are provided, but the IGBPclassification scheme is the most amenable to the Pan-Arctic region.

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    The pan-European High Resolution (HR) Image Mosaic 2006 provides HR2 (High Resolution: 20 meter) coverage over Europe for the continuation of Corine Land Cover like exercises and for the generation of HR layers by the EU and EEA. The surface covered by the image dataset is 5.8 million square kilometres and has a spatial resolution of 20 meters. The imagery is composed during specific acquisition windows in 2011, 2012 and 2013. Coverage 2 acquisitions are expected to be 6 weeks away from Coverage 1, down to a minimum of 2 weeks for northern countries, including United Kingdom. The ± 6 weeks criteria might not be strictly applied over Atlantic Islands and French DOMs (seasonal changes are limited in the equatorial DOMs). Images are derived from the following satellite sensors: RapidEye constellation The mosaic primarily is used as input data in the production of various Copernicus Land Monitoring Service (CLMS) datasets and services, such as land cover maps and high resolution layers on land cover characteristic and can be also useful for CLMS users for visualizations and classifications on land. The input imagery for the creation of the mosaic is provided by ESA. Due to license restrictions, HR Image Mosaic 2006 is only available as a web service (WMS), and not for data download.

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    The pan-European High Resolution (HR) Image Mosaic 2012 provides HR2 (High Resolution: 20 meter) coverage over Europe. The surface covered by the image dataset is 5.8 million square kilometres and has a spatial resolution of 20 meters. The imagery is composed during specific acquisition windows between 2011 and 2013. Images are derived from the following satellite sensors: Resourcesat-1/-2 SPOT-4/-5 The mosaic primarily is used as input data in the production of various Copernicus Land Monitoring Service (CLMS) datasets and services, such as land cover maps and high resolution layers on land cover characteristic and can be also useful for CLMS users for visualizations and classifications on land. The input imagery for the creation of the mosaic is provided by ESA. Due to license restrictions, HR Image Mosaic 2012 is only available as a web service (WMS), and not for data download.