GeoJSON — Antimeridian Polygon Split into a MultiPolygon
The straddling block cut at 180 into two polygons that share an edge on the meridian — the interoperable form. Use it as the expected output when testing an antimeridian-splitting routine against the unsplit twin.
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"id": "am-4",
"properties": {
"name": "Survey block",
"crossesAntimeridian": true,
"splitAt": 180
},
"geometry": {
"type": "MultiPolygon",
"coordinates": [
[
[
[
179.6,
-16.2
],
[
180.0,
-16.2
],
[
180.0,
-16.6
],
[
179.6,
-16.6
],
[
179.6,
-16.2
]
]
],
[
[
[
-180.0,
-16.2
],
[
-179.7,
-16.2
],
[
-179.7,Specifications
- Format
- GeoJSON (RFC 7946)
- Crs
- WGS 84 (EPSG:4326)
- Coordinate Order
- longitude, latitude
- Encoding
- UTF-8
- Line Endings
- LF
- Features
- 1
- Geometry Type
- MultiPolygon
- Parts
- 2
- Spec Section
- RFC 7946 section 3.1.9
- Combined Width Degrees
- 0.7
- Valid
- true
Testing contract
Reference control- Scenario
- Split the unsplit polygon twin at the antimeridian and compare with this file.
- Expected result
- Two rectangles are produced, one ending exactly at 180 and one starting exactly at -180, together covering 0.7 degrees of longitude.
What is a .geojson file?
GeoJSON is a JSON-based format for encoding geographic data structures such as points, lines, and polygons, along with their properties. It uses WGS84 longitude-latitude coordinates and standard feature and feature-collection objects. It is a common interchange format for web mapping and GIS.
How to use this file
Use an example GeoJSON file to test geometry parsing, coordinate handling, and mapping libraries or GIS pipelines that render or analyze spatial features.
How to use this file for testing
“GeoJSON — Antimeridian Polygon Split into a MultiPolygon” is a deterministic Novus Examples fixture for Geospatial, Conversion testing, Error handling. GeoJSON, GPX, and KML files with points, lines, polygons, and tracks — for testing map tools, route parsers, and geo importers.
Documented properties for this file: UTF-8 · LF · GeoJSON (RFC 7946). Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
Geospatial fixtures publish one invented territory across formats, with the coordinate reference system and feature counts documented in specs. Convert or reproject and diff against the twin in the same group; edge-case geometries state exactly which assumption they are built to break.
Code examples
import geopandas as gpd
gdf = gpd.read_file("antimeridian-polygon-split.geojson")
print(gdf.head())
print(gdf.crs)Related files
- geojsonGeoJSON — Clockwise Exterior Ring (right-hand rule violated)Both rings of the Mill Court parcel are wound the wrong way round: the exterior clockwise, the interior counter-clockwise. RFC 7946 mandates the right-hand rule, and consumers that rely on winding to tell holes from shells will read this polygon inside out.
- geojsonGeoJSON — Intentionally Invalid: Hole Outside Its ShellIntentionally invalid: the second ring is a whole separate parcel filed as an interior ring of the first, which OGC Simple Features forbids. It is what happens when a MultiPolygon is flattened into a Polygon by concatenating rings.
- geojsonGeoJSON — Intentionally Invalid: Self-Intersecting RingIntentionally invalid: a bowtie ring whose two lobes wind in opposite directions, so the shoelace areas nearly cancel. Buffer, intersection and area operations on this geometry return nonsense rather than failing, which is why it belongs in a validation suite.
- geojsonGeoJSON — Intentionally Invalid: Unclosed Polygon RingIntentionally invalid: the parcel's exterior ring omits the repeated closing position that RFC 7946 requires. Many readers close it silently, which hides the producer's bug until a stricter consumer downstream rejects the data.
- geojsonGeoJSON — LineString Passing Over the North PoleA flight path that goes up one meridian, touches the pole, and comes down the antipodal meridian — so longitude jumps by exactly 180 degrees at the middle vertex. Renderers that interpolate in longitude draw a horizontal streak across the whole map instead.
- geojsonGeoJSON — Points Exactly at the PolesThree points at exactly plus or minus 90 degrees latitude, two of which are the same physical place written with different longitudes. Web Mercator cannot represent either pole — latitude 90 projects to infinity — so this is the fixture that catches divide-by-zero and NaN in a reprojection path.
Generated by generation/geospatial.py. Free for any use, no attribution required — license.