anchor.diff:                <p>Viewing data for the first period available via the time slider may include alerts that reflect detections from the February 2000 to December 2005 training period as the algorithm "catches up" post-training. </p>
                 <p>The GFW team has clipped out some data in regions where data quality is suspected to be low because of persistent cloud cover over identified ecoregions. This covers parts of Liberia, Venezuela, Guyana, Vietnam, Laos, and Burma/Myanmar. The current extent of the FORMA alerts is available for viewing here—<a href='http://wri-01.cartodb.com/viz/3cc0f4c2-56d3-11e3-80bb-c8600054c0d1/embed_map?title=true&description=true&search=false&shareable=false&cartodb_logo=false&layer_selector=false&legends=false&scrollwheel=true&sublayer_options=1&sql=&zoom=3&center_lat=-1.845383988573187&center_lon=16.34765625' target='_blank'>FORMA geographic extent</a>.</p>
                 <p>The <a href='https://github.com/wri/forma-clj' target='_blank'>algorithm</a> behind the FORMA alerts is constantly evolving to fix bugs and improve accuracy. As a result, what appears on the site and the results of analyses conducted on the site may change over time. It is important to always include the access date when citing FORMA. For questions, please contact <a href='mailto:gfw@wri.org'>gfw@wri.org</a>.</p>
  +              <p>For the purpose of this study, “tree cover” was defined as areas with greater than 25% canopy cover (as defined by the <a href='http://journals.ametsoc.org/doi/abs/10.1175/1087-3562(2003)007%3C0001%3AGPTCAA%3E2.0.CO%3B2' target='_blank'>Vegetation Continuous Fields data set</a>), and change was measured without regard to forest land use. Tree cover assemblages that meet the 25% threshold include intact forests, plantations, and forest regrowth.</p>
                 <p>When zoomed out, this data layer displays some degree of inaccuracy because the data points must be collapsed to be visible on a larger scale. Zoom in for greater detail.</p>
               </dd>
             </dl>
  
positive.code:         <div class='source_table'>
            <dl class='sources_row'>
              <dt>Function</dt>
              <dd>Detects areas where forest clearing is likely to have recently occurred</dd>
            </dl>
            <dl class='sources_row even'>
              <dt>Resolution/scale</dt>
  
negative.code: 
          <div class='source_summary'>
            <h3 class='overview_title'>Overview</h3>
            <p>FORMA is a near real-time tree cover loss alert system. It uses a cloud computing <a href="https://github.com/reddmetrics/forma-clj" target="_blank">algorithm</a> to analyze frequently updated satellite imagery along with complementary information on factors that affect tree cover loss, such as fires and precipitation. The system generates twice-monthly “alerts” for the world’s <a href="http://wolfweb.unr.edu/~ldyer/classes/396/olsonetal.pdf" target="_blank">humid tropical forests</a> that identify 500 x 500 meter areas where new, large-scale loss is likely to have occurred.</p>
  
            <p>FORMA is designed for quick identification of new areas of tree cover loss. The system analyzes data gathered daily by the <a href="http://modis.gsfc.nasa.gov/about/" target="_blank">MODIS</a> sensor, which operates on NASA’s Terra and Aqua satellites. The FORMA alerts system then detects pronounced changes in vegetation cover over time, as measured by the <a href="http://earthobservatory.nasa.gov/Features/MeasuringVegetation/measuring_vegetation_2.php" target="_blank">Normalized Difference Vegetation Index (NDVI)</a>, a measure of vegetation greenness. These pronounced changes in vegetation cover are likely to indicate forest being cleared, burned, or defoliated.</p>
  
            <p>FORMA alerts only appear in areas where the probability of tree cover loss is greater than or equal to 50%.</p>
  
            <p>Upcoming upgrades to FORMA include improving the resolution to 250 × 250 meters, and expanding coverage to tropical dry forest and eventually to other biomes across the global scale.</p>
  
  