Location defining guidelines

Overview

To order geospatial collections, you need to specify a location that you want to get. Different collections accept different location types.

Location of interest types

Area of interest (AOI)

A polygon, that is, a two-dimensional closed shape, defined by geographical coordinates. The first and last coordinate pairs of a polygon are identical. Polygons should contain no more than 999 vertices.

Depending on the collection, you will get one of the following when ordering an AOI:

• Full scenes intersecting the AOI
• The exact area you defined

Point of interest (POI)

A point, that is, a specific location, defined by longitude and latitude.

When ordering a POI, you will get a full scene centered on the defined POI.

How to define a location in the console

AOI

• Search for a location. Start typing a name of a place in the Search location bar and select a prompt from a drop-down list.

• Draw a polygon. Click on the top right.

• Upload a file. Click in the Search location bar.

POI

• Draw a point. Click on the top right.

• Upload a file. Click in the Search location bar.

File formats for different platforms

Shapefile

The Shapefile file format should consist of at least 3 required files:

• .shp — feature geometry
• .shx — an index position
• .dbf — attribute information

Other optional files can be included in a Shapefile as well, such as .cpg, .prj, .xml, .sbn, or .sbx.

GeoJSON

GeoJSON files store coordinates in JSON format. Both extensions, .geojson and .json, are accepted. Allowed types of coordinates are Point and Polygon.

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "coordinates": [12.771, 17.538],
        "type": "Point"
      }
    }
  ]
}

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "coordinates": [
          [
            [23.5205528237677, 45.637193443295615],
            [23.5205528237677, 45.37207697693091],
            [23.92165183941367, 45.37207697693091],
            [23.92165183941367, 45.637193443295615],
            [23.5205528237677, 45.637193443295615]
          ]
        ],
        "type": "Polygon"
      }
    }
  ]
}

KML

Keyhole Markup Language (KML) is an XML-based format initially developed for Google Earth.

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<Placemark>
  <name>New York City</name>
  <description>New York City</description>
  <Point>
    <coordinates>-74.006393,40.714172,0</coordinates>
  </Point>
</Placemark>
</Document>
</kml>

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Placemark>
    <name>The Pentagon</name>
    <Polygon>
      <extrude>1</extrude>
      <altitudeMode>relativeToGround</altitudeMode>
      <outerBoundaryIs>
        <LinearRing>
          <coordinates>
            -77.05788457660967,38.87253259892824
            -77.05465973756702,38.87291016281703
            -77.05315536854791,38.87053267794386
            -77.05552622493516,38.868757801256
            -77.05844056290393,38.86996206506943
            -77.05788457660967,38.87253259892824
          </coordinates>
        </LinearRing>
      </outerBoundaryIs>
    </Polygon>
  </Placemark>
</kml>

WKT

Well-known text (WKT) is used to represent vector geometry objects. Allowed types of coordinates are Point and Polygon.

Examples of WKTs:

• POINT (30 10)
• POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))

Types of not valid polygons

• Shadock polygons aren't allowed, that is, when a polygon intersects the image footprint in more than one segment, thus creating more polygons.

  Fix shadock polygons in one of the following ways:

  • Modify the size of the polygon, so that it intersects the image footprint in one segment.
  • Split the polygon into more polygons, so that each one intersects the image footprint in one segment.

• Sliver polygons aren't allowed, that is, polygons with a very small area but with a very large perimeter.

• Polygons that contain holes or self-intersections aren't allowed. If needed, apply a simplification algorithm — for example, Douglas-Peucker.