Balloon probe (measuring instrument)
As balloon probes are measuring instruments of the meteorology and aerology referred to by a supporting strong balloon be brought into greater heights. They are built for several areas of application:
- as a weather balloon for measuring air temperature , humidity, high-altitude winds, etc .; Instruments equipped with telemetry are called radiosondes
- for aerial photography - photogrammetry (flight altitudes up to a few kilometers)
- for archeology also as a tethered balloon
- as a high target for geodetic stellar triangulation (first around 1955)
- for research into cosmic rays
- and for various special purposes.
The balloons have a diameter of between 1 meter and several meters , depending on the payload and the planned flight altitude . As a result of the increasing air pressure , the balloon expands more and more until it finally bursts. Devices with more valuable instruments are allowed to float to the ground with small parachutes ; they have an address to which the finder is asked to return.
The flight path can be measured by analyzing radio signals or optically / photographically. For visual tracking, motorized theodolites and special kinetheodolites were developed in the 1950s , while so-called ballistic cameras have been around since the first rocket tests in the 1940s . The best-known of these camera types is the BC-4 from Wild-Heerbrugg.
Unmanned balloon probes with self-registering measuring instruments have been around since 1890, but in the form of radiosonde only since 1929.
Particularly large or complex balloon probes are often referred to as research balloons.