SondeHub is the community radiosonde tracking network: hundreds of receiver stations worldwide feeding one live map of every sonde in the air. SondeFox talks to it in both directions, but not symmetrically. This page keeps three things separate: exact saved-flight and prediction reads, the SondeFox Test debug build's temporary SondeHub Live map preview, and data the app can upload only after you opt in. Production v0.14.0 does not expose Network Live.

What SondeFox reads from SondeHub

Working Read-only; each path has its own activation and network rules.

The read side has two production paths and one separately installed debug-only path:

• Exact and recent flight history, for Saved Flights. Save a sonde's exact serial (professional) or payload callsign (amateur) and the app fetches that flight's history from the SondeHub archive, keeps it updated, and can backfill the full record. It is exact-match only; the screen's own hint reads "Exact match only; no fuzzy archive search". If you enable Auto-update for a saved flight, Android may make its network-constrained refresh requests in the background about every 15 minutes.
• Landing predictions. With "Predict where it will land (SondeHub)" enabled in Settings (off by default), a running local chase polls the community predictor (GET /predictions) for eligible radiosonde targets every 30 s, 1 min or 5 min and draws the predicted descent path and landing marker on the Chase map. Offline, or for a serial SondeHub does not know, the app falls back to a local linear estimate labelled "local est.".
• SondeHub Live (SondeFox Test debug build only). Production v0.14.0 does not expose the Network Live source or authorize its REST/MQTT runtime. In the debug build, after you select the preview on the 2D Chase map, review its disclosure, and choose Wi-Fi-only or metered access, the app makes bounded discovery requests driven by the settled viewport. This temporary foreground session is detailed below.

None of these read paths turns on telemetry, station-position, chase-car, recovery, or developer-capture uploads. Those remain separately controlled as described below.

Following a flight you are not receiving

Saved Flights is the way to watch a SondeHub flight with no SDR attached and no local decode: a sonde still over the horizon, a flight a friend is chasing, or a launch you want to review after the fact.

1. Find the identity

   Look the flight up on sondehub.org (professional) or amateur.sondehub.org (amateur) and copy the exact serial or payload callsign.

2. Open Saved Flights

   On the Chase tab, expand the below-map controls with the chevron and tap Saved Flights. The same button exists on the List tab.

3. Save the identity

   Under "Add or update an exact identity", pick the Professional or Amateur chip, type the serial or callsign exactly, then tap Save & Update. A typo produces an empty card, not an error; there is no fuzzy search.

4. Sync it

   Update Now fetches the recent history. Backfill full history downloads the older archive for that exact flight. Auto-update is off until you enable it; while enabled, Android may run network-constrained refresh requests in the background about every 15 minutes, and a flight still in the air carries a LIVE label.

5. Watch it

   View on Chase draws the flight on the map in place of live content, with playback at 1×, 5×, 20× or 60×.

Remote updates default to Wi-Fi only; the first update on cellular asks for consent. Imported history stays usable with no connection. As the screen itself puts it: "Durable local telemetry and exact SondeHub imports remain available offline."

What SondeFox can upload, if you opt in

Every upload path is off by default and stays off until you enable it under Set > SondeHub. Uploads also require a station callsign; there is no anonymous upload. A status row in the same section shows last sync time, upload counts, throttle state, and the last error.

Telemetry upload

Cleared: RS41 & DFM17 All other types held

With "Upload decoded telemetry" on and a callsign set, SondeFox contributes decoded frames to the network (PUT /sondes/telemetry). Two sonde types are cleared to publish: RS41 and DFM17. Every other type (DFM06/09, M10/M20, iMet, RS92, and the rest) decodes, maps and chases exactly as normal, but its frames are held from upload. A protocol is cleared only after its decode has been independently validated against SondeHub's own multi-station data.

When the sonde you are tracking is a held type, the app says so itself:

The upload path is built to be a well-behaved network citizen:

• CRC-valid frames only. Garbage never leaves the device, so your station does not pollute the public stream.
• 15 s batching. Frames are queued and flushed every 15 seconds, the minimum cadence SondeHub asks uploaders to keep, instead of hitting the API per frame.
• Rate-limit backoff. On HTTP 429 the app honors the server's Retry-After header and re-queues the batch rather than retrying blindly.
• Callsign required. Uploads are tied to a station identity you choose.
• Station metadata. The Receiver and Antenna fields in Settings travel with decoded telemetry as uploader_radio and uploader_antenna. Contact email is not a decoded-telemetry field; it is used only in the listener-position documents described next.

Station position and chase-car position

Cleared 2026-08-01

Sending your own position to SondeHub is governed by two separate toggles, each off by default. "Station position upload" reports a receiver document (PUT /listeners; the similarly named GET /listeners/telemetry is the read side, a different endpoint). That document contains your effective listener position (GPS by default; manual only when Station position upload is also enabled and manual coordinates are selected), callsign, SondeFox software name and version, a mobile flag, configured radio and antenna metadata, and your configured contact email; a non-personal placeholder is used when the email is blank. "Chase-car position upload" sends the same document with mobile=true so you appear as a chase station on the public SondeHub map; the fixed-station form uses mobile=false. One clearance covers both; it was granted on 2026-08-01. Turning on telemetry upload does not turn either of these on.

Recovery reports

Working

The Recovered button opens a dialog that files a recovery report (PUT /recovered) with the sonde serial, recovery coordinates including altitude, your callsign or reporter name, recovered/not-found status, notes, SondeFox as the recovery-software identifier, and a planned-status flag (currently false). From sonde details, those coordinates use the phone's current GPS fix when available and otherwise fall back to the sonde's shown position; the chase control uses the shown sonde position. The dialog displays latitude and longitude before submission. Nothing is sent until you confirm; every report is a manual, one-off action. Filing a report requires the telemetry opt-in and a callsign, the same as any other upload. Reports tell the community which sondes are already accounted for.

One boundary worth stating: the development capture toggles under Set > Development record SondeHub-shaped payloads for debugging, but they upload only to the developers' private debug server, never to SondeHub. Their "Dry-run captured payloads on SondeHub" button is held in this build and returns an error by design.

SondeHub Live foreground preview (debug only)

SondeFox Test debug build only Production v0.14.0 off

SondeHub Live is currently available only in the separately installed SondeFox Test debug build. Production v0.14.0 does not expose the Network Live source or authorize its REST/MQTT runtime. In the debug build, select SondeHub Live · preview on the live 2D Chase map, review the disclosure, and choose Wi-Fi-only or metered access. It does not need or start an SDR. The choice under Set > SondeHub > SondeHub Live network access can later revoke metered use.

In that debug preview, discovery follows the map you deliberately view, not an automatic device-location query. At broad zooms the app requests one bounded /sondes?last=600 snapshot, then ranks it around the viewed centre locally; it does not send that centre or open a realtime connection. At closer zooms it sends the viewed centre and search radius to SondeHub, obtains one secure MQTT endpoint, and subscribes to at most twenty-four selected exact sondes/{serial} topics. The map never follows a balloon automatically; following is a separate choice and can make later viewport queries reflect your approximate location.

Current native 3D camera reports do not drive debug-preview discovery: without an owner-approved ground-viewport calibration, that path returns no viewport and fails closed. Use the 2D map to choose the discovery area.

The debug session is temporary and fail-closed. It stops when the app leaves the foreground, archive playback begins, network policy denies access, a safety cap is exceeded, or you return to Local SDR. Network points stay in memory, do not enter the local-RF Sondes list or Saved Flights, and do not gain local signal or upload status. The preview does not itself upload telemetry, listener, chase-car, or recovery data; a separately active local SDR chase can continue under its own upload settings until you stop it.

Offline behavior

Decoding is fully local, so losing signal bars does not end a chase. SondeFox caches the last known target and prediction and keeps navigating; when the connection comes back, any queued telemetry still within the upload window is flushed automatically, and Saved Flights imports remain readable throughout. In the SondeFox Test debug build, SondeHub Live pauses while offline and does not turn its in-memory points into saved history; production authority is off, so there is no Network Live session to pause.

Privacy: exactly what leaves the device

The model is strict: nothing uploads to SondeHub without opt-in.

One more thing the in-app opt-in flow tells you, repeated here: anything you upload joins the public SondeHub stream and may be redistributed by SondeHub and downstream consumers. Opt in with that in mind, and see the site-wide privacy notes for the rest.