Near-Space API

The Near-Space API provides data on objects in the atmosphere and near-space environment: radiosondes (weather balloons) tracked via SondeHub, and aircraft tracked via ADS-B transponders from the OpenSky Network.

Radiosondes

Radiosonde data is sourced from SondeHub, a community-driven radiosonde tracking platform. Sondes are launched by national weather services worldwide and carry sensors measuring temperature, humidity, pressure, and wind.

List Sondes

GET /api/sondes

Response

{
  "sondes": [
    {
      "serial": "V3541234",
      "type": "RS41",
      "manufacturer": "Vaisala",
      "lat": 39.82,
      "lon": -104.95,
      "alt": 18500.0,
      "temp": -52.3,
      "humidity": 12.0,
      "pressure": 65.2,
      "vel_v": 5.2,
      "frequency": 403.5,
      "flight_status": "ascending",
      "datetime": "2026-02-14T22:30:00Z"
    }
  ],
  "count": 45,
  "active_count": 28,
  "landed_count": 17
}

Sonde Fields

Field	Type	Description
`serial`	`string`	Sonde serial number
`type`	`string\|null`	Sonde model (e.g. `RS41`, `DFM09`)
`manufacturer`	`string\|null`	Manufacturer (e.g. `Vaisala`, `Graw`)
`lat`	`float\|null`	Latitude
`lon`	`float\|null`	Longitude
`alt`	`float\|null`	Altitude in meters
`temp`	`float\|null`	Temperature in Celsius
`humidity`	`float\|null`	Relative humidity (%)
`pressure`	`float\|null`	Atmospheric pressure in hPa
`vel_v`	`float\|null`	Vertical velocity in m/s
`frequency`	`float\|null`	Transmit frequency in MHz
`flight_status`	`string`	`ascending`, `descending`, or `landed`
`datetime`	`string\|null`	Last reported timestamp

Landing Predictions

Predicted landing locations for sondes currently in flight.

GET /api/sondes/predictions

Response

{
  "predictions": [
    {
      "serial": "V3541234",
      "lat": 39.91,
      "lon": -104.72,
      "alt": 0.0,
      "datetime": "2026-02-14T23:45:00Z"
    }
  ],
  "count": 1
}

Launch Sites

Known radiosonde launch sites (stations).

GET /api/sondes/sites

Response

{
  "sites": [
    {
      "station": "72469",
      "station_name": "Denver/Stapleton",
      "lat": 39.77,
      "lon": -104.87,
      "alt": 1625.0
    }
  ],
  "count": 1
}

Sonde Summary

A compact count of sonde flight states.

GET /api/sondes/summary

Response

{
  "active_count": 28,
  "landed_count": 17,
  "total_count": 45
}

Refresh Sonde Data

POST /api/sondes/refresh

{
  "status": "refreshing",
  "message": "Sonde refresh started in background"
}

Aircraft (ADS-B)

Aircraft data is sourced from the OpenSky Network, providing real-time positions of aircraft within a bounding box around the observer location.

List Aircraft

GET /api/aircraft

Response

{
  "aircraft": [
    {
      "icao24": "a12345",
      "callsign": "UAL1234",
      "origin_country": "United States",
      "lat": 39.85,
      "lon": -104.67,
      "baro_altitude": 10668.0,
      "geo_altitude": 10700.0,
      "velocity": 245.0,
      "track": 180.0,
      "vertical_rate": 0.0,
      "squawk": "1200",
      "category": 3,
      "on_ground": false
    }
  ],
  "count": 42,
  "bbox": {
    "min_lat": 38.74,
    "max_lat": 40.74,
    "min_lon": -105.99,
    "max_lon": -103.99
  }
}

Aircraft Fields

Field	Type	Description
`icao24`	`string`	ICAO 24-bit transponder address (hex)
`callsign`	`string\|null`	Aircraft callsign
`origin_country`	`string\|null`	Country of registration
`lat`	`float\|null`	Latitude
`lon`	`float\|null`	Longitude
`baro_altitude`	`float\|null`	Barometric altitude in meters
`geo_altitude`	`float\|null`	Geometric (GPS) altitude in meters
`velocity`	`float\|null`	Ground speed in m/s
`track`	`float\|null`	Track angle in degrees (clockwise from north)
`vertical_rate`	`float\|null`	Vertical rate in m/s
`squawk`	`string\|null`	Transponder squawk code
`category`	`int\|null`	Aircraft category (ADS-B emitter category)
`on_ground`	`bool`	Whether the aircraft is on the ground

The bbox field shows the geographic bounding box used for the query, centered on the observer location.

Aircraft Summary

GET /api/aircraft/summary

Response

{
  "count": 42,
  "highest_alt": 12192.0,
  "lowest_alt": 914.0
}

Refresh ADS-B Data

POST /api/aircraft/refresh

{
  "status": "refreshing",
  "message": "ADS-B refresh started in background"
}