Page 9 - EngineerIT AugustSeptember Issue 2026

SCIENCE

Long-duration platform
experiments
Flights lasting many months
allow the study of electronics
reliability in extreme cold. In these
conditions, batteries degrade and
solar panels age faster.

Long-duration Pico balloons are
particularly useful for studying
stratospheric circulation stability
over extended periods because
conventional weather balloons
remain airborne for only a few
hours. This is a unique niche where
amateur experimentation can
contribute meaningfully.

There are, however, realistic
limitations. Despite their value,
Pico balloon measurements
have important constraints.
Sensor calibration is often poor,
payload orientation can introduce
bias, such as solar heating
effects, and altitude is not tightly
controlled, resulting in inconsistent
measurement standards.

As a result, the data is best suited
to trend observation and trajectory
analysis rather than precision
meteorology.

Weak Signal Propagation
Reporter network
The radio transmitter (WSPR
beacon) is a low-power Pico PI
with a temperature-controlled
crystal oscillator, which must be Stewart Clark ZR1WT with a tracker.
very stable. The Pico PI is switched
on only when the voltage exceeds The WSPRnet website provides a simple user interface for querying the database,
a threshold. If it were connected a mapping facility and many other features.
directly to the solar panels, it could
enter an unstable operating state. Not all balloons use WSPR as a means of telemetry. Some use other systems,
such as the Automatic Packet Reporting System (APRS). The key thing about WSPR
The antenna is a half-wave is that it is extremely sensitive. It can detect signals down to -28 dB below the
dipole. WSPR is a great way to noise floor. The transmit power of the balloon can be as low as 20 milliwatts.
monitor the balloon because tens
of thousands of amateurs have Pico balloons are more than just a hobby. Stewart Clark ZR1WT discussed their
automatic WSPR receivers listening scientific value and global tracking capabilities during a presentation at the
24/7. Each time a valid WSPR recent South African Radio League Technical Symposium. His presentation,
message is successfully decoded, "Telemetry via Repurposed WSPR for Pico Balloons", can be viewed on YouTube.
it is uploaded to the WSPRnet
website. Email: hans@comsa.africa

9 | EngineerIT August/September 2026