{
  "schema": {
    "title": "A localisation form",
    "type": "object",
    "required": [ "lat", "lon" ],
    "properties": {
      "lat": { "type": "number" },
      "lon": { "type": "number" }
    }
  },
  "uiSchema": { "ui:field": "geo" },
  "formData": { "lat": 0, "lon": 0 }
}