Voltitude are designing a range of Payloads for Stratospheric platforms or ‘HAPS’ – High Altitude Pseudo Satellites. These platforms, powered by solar power, can stay airborne for weeks and months on end providing persistent services such as atmospheric sensing, imaging, and connectivity.


Micro dropsondes to improve weather predictions – reduce carbon emissions and mitigate climate change through improved data intelligence.

Numerical Weather Prediction (NWP) models generate global and regional weather forecasts, using current weather observations as their initialisation state, in the form of 1000s of radiosonde balloons each weighing ~500g, released twice daily, which tell the models what windspeed, temperature, and humidity is present in the atmosphere.

The global weather observation system has large gaps, especially over oceans, where there are few regular observations. Such regions present uncertainty in the atmospheric state and introduce errors, limiting the forecast skill and range of the NWP models.

Traditional radiosonde

There is a clear need to improve observations over remote areas and it is desirable to make more accurate analyses than currently possible in areas where forecast errors grow rapidly, e.g. in areas of intense convection such as tropical storms, tropical cyclones and hurricanes, or from baroclinic zones e.g. regions where there is a large horizontal change in temperature, humidity, and or pressure, such as across a frontal zone. This will be key to mitigating the effects of climate change across the planet.

RadioSondes can be dropped from aircraft, (which become DropSondes) for targeted observations however extensive use is prohibited by cost and aircraft flight range. Until now, the use on HAPS was prohibited due to the mass required to carry a significant quantity. Voltitude have designed a new form of DropSonde, which we have termed, when combines with a HAPS platform, a ‘StratoSonde(TM)‘ . This new technology combines a 40g dropsonde with a dispensing system for use with any HAPS systems currently being developed.

40g micro dropsonde only 50mm in diameter
Lightweight dispensing system carries 3 months daily observations and can be fitted to a range of platforms for under 4kg total mass

The StratoSonde(TM) system can operate as a constellation of sensors, utilising a range of HAPS assets, providing a low-cost, wide-area observation system over remote areas, or respond dynamically to the needs of meteorologists in operational centres to gather observations “on demand” from specific areas and features of interest.

Dedicated encrypted links between the dispenser, dropsonde and iridium do not require any platform data services for operation.

If you are interested in integrating our payload into your HAPS asset, please get in touch via the contact form