geo_s2cell_to_polygon()

  • Article
  • 09/30/2024

Applies to: ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Calculates the polygon that represents the S2 Cell rectangular area.

Read more about S2 Cells.

Syntax

geo_s2cell_to_polygon(s2cell)

Learn more about syntax conventions.

Parameters

Name Type Required Description
s2cell string ✔️ S2 cell token value as it was calculated by geo_point_to_s2cell(). The S2 cell token maximum string length is 16 characters.

Returns

Polygon in GeoJSON Format and of a dynamic data type. If the s2cell is invalid, the query produces a null result.

Note

S2 Cell edges are spherical geodesics.

Examples

Run the query

print s2cellPolygon = geo_s2cell_to_polygon("89c259")

Output

s2cellPolygon
{
"type": "Polygon",
"coordinates": [[[-74.030012249838478, 40.8012684339439], [-74.030012249838478, 40.7222262918358], [-73.935982114337421, 40.708880489804564], [-73.935982114337421, 40.787917134506841], [-74.030012249838478, 40.8012684339439]]]
}

The following example assembles GeoJSON geometry collection of S2 Cell polygons.

Run the query

datatable(lng:real, lat:real)
[
    -73.956683, 40.807907,
    -73.916869, 40.818314,
    -73.989148, 40.743273,
]
| project s2_hash = geo_point_to_s2cell(lng, lat, 10)
| project s2_hash_polygon = geo_s2cell_to_polygon(s2_hash)
| summarize s2_hash_polygon_lst = make_list(s2_hash_polygon)
| project bag_pack(
    "type", "Feature",
    "geometry", bag_pack("type", "GeometryCollection", "geometries", s2_hash_polygon_lst),
    "properties", bag_pack("name", "S2 Cell polygons collection"))

Output

Column1
{
"type": "Feature",
"geometry": {"type": "GeometryCollection", "geometries": [
{"type": "Polygon", "coordinates": [[[-74.030012249838478, 40.880202851376716], [-74.030012249838478, 40.8012684339439], [-73.935982114337421, 40.787917134506841], [-73.935982114337421, 40.866846163445771], [-74.030012249838478, 40.880202851376716]]]},
{"type": "Polygon", "coordinates": [[[-73.935982114337421, 40.866846163445771], [-73.935982114337421, 40.787917134506841], [-73.841906340776248, 40.774477568182071], [-73.841906340776248, 40.853401155678846], [-73.935982114337421, 40.866846163445771]]]},
{"type": "Polygon", "coordinates": [[[-74.030012249838478, 40.8012684339439], [-74.030012249838478, 40.7222262918358], [-73.935982114337421, 40.708880489804564], [-73.935982114337421, 40.787917134506841], [-74.030012249838478, 40.8012684339439]]]}]
},
"properties": {"name": "S2 Cell polygons collection"}
}

The following example returns a null result because of the invalid s2cell token input.

Run the query

print s2cellPolygon = geo_s2cell_to_polygon("a")

Output

s2cellPolygon