Talk:Geohash

GeoJSON rectangle

At http://geojson.io/#map=19/1.28660/103.85437 you can draw the BBOX of this Map Feature:

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              103.85447591543196,
              1.2867406074056607
            ],
            [
              103.85454565286636,
              1.2867406074056607
            ],
            [
              103.85454565286636,
              1.286783511927691
            ],
            [
              103.85447591543196,
              1.286783511927691
            ],
            [
              103.85447591543196,
              1.2867406074056607
            ]
          ]
        ]
      }
    }
  ]
}

Testing S2

See https://www.npmjs.com/package/s2-geometry

// run at https://npm.runkit.com/s2-geometry
var S2 = require("s2-geometry").S2;

var lat = 41.2574449;
var lng = -112.7089465;
var level = 22;
var key = S2.latLngToKey(lat, lng, level);
var id = S2.keyToId(key);

Benchmark places

A map-feature group of near-places (A) and another place (B) far away the first group.

Group.id	Place name and Wikidata-link	scale	ISO lat/long	UTM	Notes
A1	Washington Monument/center	cm²	38.889475, -77.035244	18S 323483 4306480	The obelisk at Washington DC. Cited as benchmark by cmar.csiro.au/csquares. There are also a report with precise coordinates in 2011 (latitude N 38° 53’ 22.08257 ± 2.0 mm NAD83, longitude W 77° 02’ 06.86428 ± 1.0 mm NAD83).
A2	Josephine Shaw Lowell Memorial Fountain (at Manhattan/NY)	?	40.754, -73.9841	18T 585756 4511946	Cited as benchmark by Minh Nguyễn 2016
A3.1	Central Park (NY)	3.4 km²	40.7825, -73.966111	18T 587238 4515127	Cited as benckmark by ycombinator.com.
A3.2	Alexander Hamilton's statue	~1m²	40.781028, -73.964556	18T 587371 4514965	Located at Central Park/NY, has granite statue into a ~1×1 m pedestal.
A3.3	Delacorte Theater	~1km²	40.7801, -73.968767	18T 587017 4514858	Located at Central Park/NY, it is a ~1/3 a of circle of ~30 m radius.
B.1	Merlion fountaine	~30m²	1.287022, 103.854689	48N 372579 142283	x
B.2	Merlion Park	?	1.28683, 103.855	48N 372614 142262	x
C	Rue François-Ier	~10km²	48.8679, 2.30497	31U 449030 5413004	Near Champs Élysées, Paris. Size 20×850 m