Dr Hugo Ricketts (Unit 1 - Manchester)

Dr Philip Rosenberg (Unit 2 - Leeds)

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Instrument Support Level 1

Instrument Support Level

Instrument Support Level 1

Manufacturer & Model

Windsond S1

CEDA Archive Name

ncas-rapidsonde-1, ncas-rapidsonde-2

Data Products


Insurance Value


Physical Dimensions

45 cm x 55 cm x 24 cm, 9kg


45 cm x 55 cm x 24 cm, 9kg

Daily Facility Charge



Windsond Reusable Radiosonde

This is a weather balloon boundary layer sounding system which is small in size and provides real-time wind, temperature, humidity profiles. The sounding station software can predict and control the landing location for the sonde making the sonde recovery and reuse reliable.


Measure wind direction, wind speed and temperature
Hygrometer to measure air humidity and dew point (additional option)
Barometer to improve the altitude accuracy from 100m to 7m
Simple sonde activation by a switch. Sounds indicate when the sonde is ready for launch.
Sonde peak altitude configurable by user, also during flight
Maximum altitude 5-8 km (17-26 thousand feet)
Radio link with programmable frequency and transmission power.
Specially developed error correcting code for more robust radio link.
No heavy metal content for small environmental impact

Ground station:

Review weather conditions even as the balloon ascends
Weather conditions are reported in graphical and text formats and exported to file in “Winds” format
Automatic averaging and interpolation of measurements
Follow the balloon live on Google Earth, right from launch to landing
Multiple sondes and multiple receivers are supported
Change settings with convenient graphical user interface
Load earlier soundings to revisit the measurements or replay the flight


This instrument is for the thermodynamic and wind profiling of the atmosphere: Specifically the boundary layer up to ~7km.

We have two units available:

  • Unit 1 – Manchester
  • Unit 2 – Leeds

The operational principles are similar to those employed by all radiosonde systems and a detailed discussion of the Vaisala system can be found here: specifically in the context of the winds. The biggest difference is in the level of on-board processing and error correction: both manufactures employ preparatory raw signal processing with little detail available. Performance comparisons are currently underway in collaboration with Windsond.

Official permissions are not required when launching this sonde due to the 12g payload

Parachutes: Not needed due to 12g payload.


The only component of the system that require calibration the sondes themselves.

  • Balloons
    • 18-inch diameter party balloons are all that is required – these are readily available on the high street or fro Amazon. The user will also need to supply the means to tie the neck of the balloon when filled. String is recommended but many users choose to use cable (zip) ties.
  • Parachutes
    • They are not required – payload is only 12g
  • Balloon filling kit
    • We do not provide either gas regulators or the means by which to fill a balloon.
    • Helium and hydrogen can both be used to fill meteorological balloons but it is recommended that HELIUM be the gas of choice even though it can be difficult to get hold of and is more expensive than hydrogen.
    • The gas in most cases will be supplied in pressurised cylinders (200 bar) and a two-stage regulator should be used to facilitate the safe filling of a balloon.
    • The thread on a gas cylinder will vary from country to country so care will need to be taken to ensure the regulator has the correct matching thread.
    • Regulators are also gas specific: it is not advisable to use a regulator specified for one type of gas with a different gas. In the UK a suitable regulator can be found here.
    • In order to ensure the balloon ascends at the desired rate either a known volume of helium must be dispensed or the balloon filled so that reaches neutral buoyancy with a particular payload: other information provided details on how to determine the volume of helium required. Hoskin Science sell a balloon filling kit which consists of a weighted nozzle: the weight of this nozzle can be adapted to meet individual payload requirements and when the balloon is neutrally buoyant with the nozzle attached the balloon contains sufficient gas. The more accurate way is to use a gas meter that allows the user to see exactly how much gas has entered the balloon. A standard domestic methane gas meter is used by ARM facility scientists.
  • Sondes
    • S1 family of sondes can only be bought directly from Windsond
  • Gas
    • Helium or helium balloon gas is available from both BOC and also from Air Liquide. These suppliers can provide the high pressurised standard cylinders but also offer a convenient low pressure, but small volume cylinder as well. These smaller cylinders are also readily available online from Amazon, party balloon suppliers, and most Calor gas retailers. How many cylinders you may require will depend on the size of the balloon used and also the volume in the cylinder: the L type BOC cylinder contains 9m3 of gas. In the UK high-pressure cylinders are standardised.
  • Met Sensors
    • At the point of launch the software will require the user to input a number of meteorological observations. The four that are compulsory are temperature (°C), relative humidity (%), wind speed (m s-1), and wind direction (°). The user will need to supply instruments to measure these.
  • Instrument Insurance
    • This system must be insured by the user for £6K.
  • Public Liability Insurance
    • We are not liable for any damage or injury arising from the deployment or operation of this instrument when unattended by the instrument scientist.
  • Shipping Expenses
    • The user is liable for all costs arising from the shipping of the instrument both to and from a deployment.
  • IS T&S
    • The user is responsible for coving the travel and subsistence expenses of the instrument scientist while attending the instrument.

Both the Manchester and Leeds units are supplied in there own single flight cases. Each case contains a ruggedised laptop, aerial, USB receiver, power cable, and manual.

Shipping dimensions: 45 cm (L) x 55 cm (D) x 24 cm (H)

Shipping weight: 9 kg

Approximately 0.5m of bench space is required for the signal processing unit, sounding computer, and ground check station and each of these will need access to 240VAC power

Although it is convenient for the balloon to be filled near to where the sounding computer is located, this is not a limiting factor for site selection.

Filling the balloon is made easier if shelter can be provided

The launch area should be clear of obstructions

The launch area should provide sufficient space for the movement of gas cylinders and for the gas cylinders to be secured.

Cylinder handling and use of compressed gas
  • Compressed gas cylinders are required for the filling of balloons. Thos handling and using such cylinders should seek training in their correct handling and usage.
Manual handling
  • When in its packing case it is recommended that two people be used when lifting. Once unpacked a single person can easily move and deploy the system. A cable is required to run from the sounding station to the antennas users should be aware that both the instrument and the power cable constitute a trip hazard and users should take appropriate actions to minimise this.
Electric safety
  • Under no circumstances should any attempt be made to open up the main body of the instrument.
Attended operation
  • Once the sonde is launched there is no requirement for the system to be attended during operation from a safety standpoint.
Permission to launch
  • The user should be in possession of flight permission, or a clear statement of exemption. In the UK this is the NOTAMS document and is issued by the CAA. In some UK locations the CAA will require the user to contact ATC on a specific number prior to flight. Users must follows CAA instructions. See Operational Requirements for instructions on how to obtain permission to fly in the UK.
  • Meteorological balloons are made from latex. Latex can induce severe allergic reaction.
  • 100 – 240VAC (at 47 – 63 Hz) in order to recharge laptop.
  • Consumption (entire system): ~ 1W
Bench space
  • Area for laptop: 40 cm x 40 cm
  • Antenna operation temperature: -40°C to 45°C
    laptop: -10°C to 45°C and moderate rain
Field Data
  • Operationally while in the field the user will parse the sounding using the sounding station software on the supplied laptop. This produces the default EDT file which is a tsv formatted text file, the user can name this file as they see fit.
Archive data