Helpful Terms

Asset: An asset is geographic data that has been uploaded to Earth Engine. There are several types of assets:

• FeatureCollection - A FeatureCollection is a .csv or shapefile data with geolocation data that can display information about its columns on the map.
• Image - An image with geolocation information so it can be displayed over the section of the map it represents.
• ImageCollection - A collection of images that will all be displayed on the map simultaneously.

Layer: A layer is a data source that can be displayed on the Delphi map. To make a data source visible on the map, it must be added to the layers list associated with the disaster.

KML file: XML notation for expressing geographic information on maps.

Map Tiles: Map imagery broken up into a set of square map tiles arranged in a grid. When a map moves to a new location, or to a new zoom level, the Maps API determines which tiles are needed and translates that information into a set of tiles to retrieve. A faster, easier alternative to Image Collections when available.

Property: A column in a dataset that we want to display on the Delphi map. For instance, if there is census data with a column for Median Income title ‘MedianIncome’, ‘MedianIncome’ is our property. Properties can be either:

• Continuous: A property that spans a range of values. For example, Median Income could go from 5,000 (dollars) to 150,000. The min value in the range will be colored white, the max colored with whatever color the user chooses, and all values in between on a gradient between the two colors.

OR

• Discrete: A property has only a few, distinct values that need to be displayed. For instance, a damage asset might have 3 levels of damage such as affected, unaffected, destroyed. Each of these levels will be given their own, specific color to display on the map.