In‑Situ Data
WindBorne balloons are capable of totally flexible altitude control between surface and stratosphere. In general, the flight profiles can be decomposed into periods of ascent and descent, typically at speeds of 1–3 m/s, and periods of mostly level flight. An example altitude profile is shown in the image below.
The standard measurement set recorded during flight consists of GPS wind, barometric pressure, ambient temperature, and relative humidity, along with GPS position and geopotential height. Downlinked sensor data undergoes quality control on the ground to eliminate erroneous or excessively noisy data.
Measurements are recorded at 10 second intervals during flight, and downlinked in packets at a configurable period, typically ≤ 7 minutes. Sensor quality control takes a further 5 mins (average) to 15 mins (worst case) after receipt of the packet. All other steps in the data delivery process take under 1 minute cumulatively, resulting in an average latency of approx. 10 mins and a worst case of approx. 25 mins between measurement and delivery of quality‑controlled observations being made available in the API.