#geospatial

The IAU Minor Planet Center list of observatory codes as an API — every site the MPC uses to identify a telescope when it publishes astrometric observations of asteroids and comets. For each of 2,700+ codes: the 3-character code, the observatory name, its east longitude and the parallax constants (rho·cos φ', rho·sin φ'). From those constants the API derives each site's geocentric latitude and a -180..180 longitude, so you can find the observatories nearest any point on Earth with a great-circle (haversine) search. Look one up by code, search by name, list them all, or find the closest sites to a latitude/longitude. Distinct from telescope-api (optics maths) — this is the registry of real observing sites and where they are. Served from memory — always fast.

api.oanor.com/observatories-api

Convert geometry between WKT (Well-Known Text) and GeoJSON, in both directions. WKT is the textual geometry format used by PostGIS, Spatialite, GEOS, JTS, Shapely and the OGC Simple Features standard (POINT (30 10), LINESTRING (...), POLYGON ((...))); GeoJSON is what web maps and JavaScript expect. The to-geojson endpoint turns a WKT string into a GeoJSON geometry, and to-wkt does the reverse from a GeoJSON geometry or Feature. Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon and GeometryCollection. Perfect for bridging a spatial database and a front-end map, importing and exporting geometry, and data-migration scripts. Pure local computation — no key, no third-party service, instant; send large geometries via POST. Live, nothing stored. 3 endpoints. Distinct from coordinate-format conversion, EPSG/CRS lookups, slippy map tiles and GeoJSON geospatial metrics.

api.oanor.com/wkt-api

Measure GeoJSON geometry on the surface of the earth. Compute the true area of a Polygon or MultiPolygon (in square metres, square kilometres, hectares, acres and square miles), find the centroid of any GeoJSON, get the bounding box (west/south/east/north) and its centre, measure the length of a LineString or MultiLineString (in kilometres, metres, miles and nautical miles), and test whether a latitude/longitude point falls inside a polygon. Accepts geometries, Features and FeatureCollections; coordinates follow the GeoJSON [longitude, latitude] order. Perfect for mapping apps, geofencing, territory and catchment analysis, route distances and spatial dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 6 endpoints. Distinct from abstract shape geometry, coordinate-format conversion, slippy map tiles and administrative-boundary data.

api.oanor.com/geojson-api

Convert geographic coordinates between every common format. Turn a latitude/longitude pair into a Plus Code (Open Location Code, as used by Google Maps), an MGRS reference (Military Grid Reference System), a UTM coordinate (zone, hemisphere, easting, northing) or a DMS string (degrees-minutes-seconds) — and convert any of those back to latitude/longitude. The /v1/all endpoint returns every format at once. Each conversion runs fully locally (no third-party service) so responses are instant and always available. Live, no cache. 6 endpoints. Built for GIS, mapping, surveying, logistics, aviation, emergency services and any app that exchanges coordinates between systems. Complements geohash and CRS lookups without overlap. No upstream key.

api.oanor.com/geoconvert-api

Open administrative boundaries as an API, powered by geoBoundaries — the open database of political administrative boundaries built by the William & Mary geoLab. For more than 200 countries and every administrative level — ADM0 (national), ADM1 (states, provinces or regions), ADM2 (counties or districts) and on down to ADM4/ADM5 local units — get the boundary's metadata (official name, the source agency that produced it, the data licence, the year represented, the number of administrative units and the mean vertex count) together with direct download links to the geometry in full-resolution GeoJSON, a simplified GeoJSON, TopoJSON and a ZIP bundle; list every administrative level available for a country with its unit count and download link; and browse the full catalogue of countries that have boundaries. The geometry itself is delivered as standard GeoJSON/TopoJSON files at the returned URLs, ready to drop into Leaflet, Mapbox, QGIS, deck.gl or any GIS pipeline. Ideal for mapping and visualisation, choropleths, spatial joins, geofencing, election and census cartography and location analytics. ISO codes are 3-letter (DEU, USA, BRA); administrative levels are ADM0 to ADM5. Data from the geoBoundaries project (CC-BY 4.0).

api.oanor.com/geoboundaries-api

Work with geohashes through a fast, fully-local API. Encode a latitude/longitude pair into a geohash at any precision (1–12), decode a geohash back to its centre coordinates with the exact bounding box and error margins, list the eight neighbouring geohash cells (north, north-east, east and so on), or get the bounding box, centre and dimensions of a cell. Geohashes turn coordinates into short sortable strings that are perfect for spatial indexing, proximity grouping and map tiling. Pure server-side computation with no third-party upstream, so responses are instant and the service is always available. Ideal for geospatial indexing and search, proximity and nearby queries, map tiles and clustering, IoT and fleet tracking, and location bucketing in databases.

api.oanor.com/geohash-api

A fast, fully-local great-circle geospatial toolkit: compute the haversine distance between two coordinates (in km, m, miles or nautical miles), the initial and final compass bearing, the geographic midpoint, the destination point reached from an origin on a bearing at a given distance, and a bounding box around a center for a radius. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for logistics, delivery and fleet apps, store locators, real-estate search, travel and mapping tools.

api.oanor.com/geo-api