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SondeHub Tracker User Guide

Mark Jessop edited this page Feb 7, 2023 · 13 revisions

The SondeHub Tracker provides live and historical view of the data contained within the SondeHub Radiosonde telemetry database. This data is openly available, and licensed under Creative Commons By-SA 2.0.

While primarily designed to assist with the tracking, recovery and re-use of meteorological radiosondes, it also provides a view of the meteorological data (for supported radiosonde types) gathered by these devices.

We will endeavour to keep this page up-to-date, however some sections may become out-of-date. If you find an error, please contact Mark at vk5qi<at>


  • SondeHub's operating costs are currently funded through a grant from Amateur Radio Digital Communications, along with regular contributions from our Patreon supporters.
  • All of the data shown on SondeHub is contributed by hundreds of receiver stations all around the world! A huge thanks to these stations for freely contributing their data.
  • The SondeHub Tracker map is based heavily on the HabHub Tracker (used for tracking hobbyist high-altitude balloon launches), and we thank Rossen Georgiev for their excellent work! Our version of the tracker switches to using Leaflet instead of the Google Maps API, and including SondeHub database specific features.
  • The Tawhiri flight-path prediction system used by SondeHub was developed by Cambridge University Space-Flight. We run our own instance of Tawhiri, utilising wind data gathered from the Global Forecast System S3 mirror.
  • The Skew-T plot library was developed by dfelix with upgrades by rittels.

How to access the tracker

  • Default Mode: or
  • Single-Sonde View:<serial_number_here> (Useful when linking to a particular radiosonde path!)
  • Historical View: (Not yet available)

SondeHub Tracker Overview

The following diagram shows the basic functions of the SondeHub Tracker in its default operating mode, when accessed via

SondeHub Tracker Overview

On first page load, all of the radiosondes on the left of the screen will be 'collapsed', only showing the radiosonde type and serial number. Clicking on an entry will expand it, showing detailed telemetry data. The map will automatically be panned and zoomed to show the selected radiosonde. Clicking a radiosonde on the map will also select and expand the corresponding list entry.

Like any other browser-based mapping system, you can pan around the map by clicking and dragging, and zoom using either the zoom controls at the bottom-right of the map, or by scrolling. The map layer can be changed using the control at the top-left of the map. If browser location services are enabled, you can pan to your own location by clicking the coordinates to the right of the search box, at the top-left of the map.

By default, only the last 3 hours of telemetry data is shown (along with any live data received since the page was loaded). Up to 12 hours of data can be loaded via this selection (a limitation designed to avoid too many datapoints appearing on the map). When requesting data for longer time periods, data will be 'decimated' to limit download sizes. Clicking on a particular radiosonde will load in the full-resolution data for that radiosonde.

To search for data from older radiosondes, either enter the serial number (if known) in the search box at the top-left of the map, or use the Historical Launch Site Data feature (described further below).

Map Legend

The following table provides some description of the different icons visible on the map.

Icon Description Icon Description
Receiver Receiver Station Radiosonde Landed Radiosonde (Landed)
Receiver - Patreon Receiver - Patreon Receiver Station (Patreon Supporter!) Radiosonde Recovered Radiosonde (Landed - Recently Recovered)
Launch Site Icon Launch Site Radiosonde Not Recovered Radiosonde (Landed - Unsuccessful Recovery)
Balloon Ascending Radiosonde (Ascending) Chase Car Chase Car
Balloon Descending Radiosonde (Descending) Predicted Burst Predicted Burst Location
Observer Location Observer location (via browser geolocation)

Note that multiple colours are used to distinguish different radiosondes, landed payloads, and chase-cars. In many cases, these icons can be clicked on to bring up more information about each object.

A Closer Look at a Radiosonde In Flight

For radiosonde currently in flight, SondeHub automatically runs flight-path predictions showing where the radiosonde is expected to travel. When a radiosonde has been selected, green lines are drawn showing which receiver station contributed the current telemetry packet.

Radiosonde in Flight

A recent feature in SondeHub is the 'Reverse' prediction. This provides an estimate of the launch site of a radiosonde that was first received in mid-air, and allows the SondeHub database to 'allocate' a radiosonde to a known launch site (Used in the Historical data view discussed further below). In the example shown above, the radiosonde was launched from a previously unknown launch site at Bodega Marine Laboratory!

SondeHub Tracker Settings

Settings Tab

The Settings Tab contains various adjustments to what and how data is shown on the map. These options are mostly self-explanatory, and may assist with de-cluttering the map in cases where lots of data is shown. You can turn them on and off to see how they affect the data on the map.

Chase Car Tab

This tab has two functions - one is to allow reporting of your location while out chasing a radiosonde, and the other is to report the recovery of (or failure to recover) a radiosonde.

Entering a callsign and enabling Chase Car mode will result in your location appearing on the map as a car icon for all users. This location will be based on whatever location your device can provide - ideally use something with a decent GPS receiver like a mobile phone!

To mark a radiosonde as recovered (... or not recovered), enter the serial number, add some notes, and submit! The 'Report Result' area will indicate if there were any issues submitting the recovery information.

If you recover a radiosonde, please report this! This helps avoid others going on a fruitless and frustrating search for a radiosonde that may have been already been collected!

Recoveries Tab

This tab shows the last 3 days of reported radiosonde recoveries. These are also displayed on the map as grey payload icons (refer the Map Legend above).

Weather Tab

This tab provides the ability to enable some weather overlays to the map, such as rain radar data. This can be useful when out chasing!

SkewT Plot Tab

This tab displays Skew-T plots of radiosonde telemetry (if available). To generate a plot, chose a radiosonde from the list at the left of the tracker, then click 'SkewT'. Note that sensor data decoding is not supported for all radiosondes, and so these plots may not be available for all radiosondes types.

Launch Site Predictions

Launch Site Information

Clicking on a Launch Site icon (display of these may need to be enabled from the Settings Tab) brings up information about the launch site, including:

  • Launch site name
  • Known launch times

Clicking the 'Generate Predictions' button will query Tawhiri for flight-path predictions for the next week of launches from the site (limited by the forecast range of the GFS weather model).

Launch Site Predictions

The landing site for each predictions is numbered incrementally starting from '1', which indicates the next launch from the site. Mousing over the landing icon will show the expected landing time (note that this is in your local timezone), and the parameters used in generating the prediction. Note that the start time used for each prediction is set to 45 minutes before the 'nominal' launch time (e.g. 00Z, 12Z).

For many launch sites, the ascent rate, burst altitude and descent rate parameters are calculated based on the many previous radiosonde flights present in the SondeHub database. If a site appears to have incorrect or incomplete data, you can contribute by clicking the link on the launch site popup.

Historical Launch Site Data

This feature is still being refined, and there may be some changes to functionality and display styling as improvements are made.

From the same Launch Site information popup, clicking 'Historical' will query SondeHub for 'summary' information on previous radiosondes flights that have been assigned to that launch site (based on reverse prediction and proximity data).

Historical Data Selection

The user can then select the Year and Month of data they wish to plot (including an 'All' option, which can result in a lot of data being plotted), and then click 'Fetch' to plot the information on the map (be patient - this may take some time!):

Adelaide 2021-12 Data

The last observed position of each radiosonde is plotted on the map as a coloured circle, with the 'cooler' colours representing last positions close to the ground, and 'warmer' colours representing last positions higher in the air (indicating the landing location is fairly uncertain). The circle being filled with dark grey indicates that the radiosonde has recovery information associated with it. (Note that recovery information only started being collected in the SondeHub DB in early 2021)

Clicking the marker brings up further details: Historical Sonde Details

Plotting the positions of all radiosondes (all years, and all months) from a given launch site can take some time, but gives an indication of the coverage of receivers for that launch site, based on the last observed altitude (and hence the colour): All Adelaide Radiosondes, 2018 through 2021

To clear the markers from the map, use the 'Delete Historical' button which will have been added at the top-left of the map.

At the current time, radiosonde that have not been assigned to a launch site cannot be queried via this tool. With further database refinements this may be possible in the future.