CopterSonde SWX

CopterSonde-SWX fleet, airborne flight, and annotated side and front views.

Built for Severe Weather Profiling

Exploded and assembled views of the CopterSonde-SWX airframe with polycarbonate shell and carbon-fiber structure.
The CopterSonde-SWX (CSWX) is a weather-sensing UAS vertical profiler engineered for high-impact environments where conventional small UAS often reach their limits. It pairs a high-thrust, tilted-body (~15°) airframe with a wind-vane flight mode and a shielded, actively ventilated sensor scoop to sample undisturbed air for thermodynamics and full 3D winds—without dedicated anemometers.

Tried and Tested Under Harsh Conditions

Sectional view of the CSWX front shell showing airflow through the aspirated sensor scoop.
Building on the CopterSonde-3D, the CSWX trades some endurance for superior power and operational robustness. Intercomparisons with CS3D, Doppler wind lidars, and radiosondes show inter-sensor temperature uniformity within ±0.2 °C across variable solar and wind regimes. LESO-based wind retrievals achieve RMSEs of 0.49 m s⁻¹ (vertical) and 1.03 m s⁻¹ (horizontal). Rain flights at KAEFS produced smooth thermodynamic profiles with no obvious precipitation-induced artifacts.

Precision Measurements When Conditions Get Extreme

The CSWX was developed to support high-resolution planetary boundary layer profiling for research and future assimilation into prediction systems—especially under sustained high winds and precipitation that ground lower-thrust platforms. Development and evaluation are described in Segales et al. (2026), Atmospheric Measurement Techniques. Dual battery modes allow operators to prioritize wind penetration (6S LiPo) or altitude/endurance (6S LiIon) depending on the mission.
Our goal with the CSWX is a resilient, high-fidelity WxUAS that advances the CopterSonde from research prototype toward operational severe-weather observing.

Sample Performance: Nocturnal Low-Level Jet

In colocated nocturnal LLJ soundings with the CS3D, the CSWX sustained winds approaching ~24 m s⁻¹ up to about 520 m, while the CS3D reached its ~20 m s⁻¹ limit near 275 m and automatically returned to launch. Thrust-margin analysis projects a safe mean-wind tolerance near 29.5 m s⁻¹ (~818 m in that profile) with roughly 35% battery energy remaining for return—nearly a 200% increase in reachable altitude relative to CS3D under the same wind conditions.

Comparison of CSWX and CS3D wind profiles and thrust performance during a colocated nocturnal low-level jet sounding.

Key Features of the CopterSonde-SWX

Custom ArduPilot firmware on a CubePilot CubeOrange extends CS3D capabilities for severe-weather operations. Highlights include:

  • High-thrust tilted-body airframe: Fixed ~15° fuselage angle with carbon-fiber plates/arms and a polycarbonate shell reduces frontal drag while preserving stability; 3110-size 900 KV motors, 80 A ESCs, and 10×4.5 in propellers produce ~3.8 kgf thrust per rotor.
  • Dual operational battery modes: 6000 mAh 6S LiPo (130 Wh) for high-wind penetration, or 9000 mAh 6S LiIon (194 Wh) for ~30% longer endurance and potentially >2000 m AGL in lighter winds.
  • Environment-aware failsafes: Wind-limit monitoring and battery-aware logic can trigger Return-To-Launch before thrust or energy margins are exhausted.
  • Wind vane flight mode (WVFM): Orients the scoop into the wind so sensors sample undisturbed inflow.
  • Shielded aspirated scoop: Three iMet-XF bead thermistors and three IST HYT-271 humidity sensors with a ducted fan (~12 m s⁻¹ aspiration) for redundant, solar-shielded thermodynamics.
  • LESO 3D wind retrieval: Full three-component winds from platform dynamics—no dedicated anemometer—validated against Doppler lidar and radiosondes.
  • Long-range command link: HereLink 2.4 GHz radio provides a robust GCS link out to ~20 km, with tailored visualization of telemetry and sensor streams.
  • Rain-resilient packaging: Near-sealed airframe with strategic vents supports wet-weather profiling alongside high-wind operations.

Platform Technical Specifications

Specifications below follow Table 1 of Segales et al. (2026) for the high-performance (LiPo) configuration from 65+ flight tests. Values outside parentheses are maximums observed in testing; values in parentheses are analytically derived upper bounds under idealized conditions (not reached in testing due to safety margins).

AIRFRAME & SYSTEMS PROPULSION (per rotor)
Body Carbon-fiber plates & arms; aluminum standoffs; ~15° tilted fuselage Brushless motor 3110-size, 900 KV
Shell 3D-printed polycarbonate Max. thrust ~3.8 kgf @ 14 000 rpm
Flight controller CubePilot CubeOrange (custom ArduPilot) Propellers 10 × 4.5 in
All-up weight 2.85 kg ESC continuous 80 A
Payload weight 300–450 g Motor power 610 (2100) W
Communications Cont. / peak current (system) 65 (140) A / 110 (264) A
Radio HereLink 2.4 GHz Input voltage 26 V (6S)
Link range ~20 km Motor temperature 65 (105) °C
POWER
High-wind mode 6S LiPo 6000 mAh (130 Wh) Endurance mode 6S LiIon 9000 mAh (194 Wh)
Hover time (to 10% batt.) 15.6 min
Meteorological Specifications Flight Envelope (LiPo mode)
Thermodynamic Mean wind tolerance 25 (31.8) m s⁻¹
Primary sensors 3× iMet-XF (T); 3× HYT-271 (RH) Gust tolerance 28 (35.4) m s⁻¹
Inter-sensor T uniformity within ±0.2 °C Forward top speed 35.4 m s⁻¹
Aspiration ducted fan ~12 m s⁻¹ Climb / descent rate 5 (12.5) / 7 (10) m s⁻¹
Temperature range −20 to 45 °C Altitude AGL 1500 (3000) m
Relative humidity 0–100% Min. air density 0.95 (0.85) kg m⁻³
Kinematic Mechanical vibration 30 m s⁻²
Method LESO (no anemometer) + WVFM Observed high-wind case ~24 m s⁻¹ @ ~520 m
Wind RMSE (vs references) 0.49 m s⁻¹ vertical; 1.03 m s⁻¹ horizontal Projected safe wind limit ~29.5 m s⁻¹
Primary variables T, RH, P; 3D wind Absolute wind limit (Thₚ≈0) ~33.5 m s⁻¹
For more information regarding the CS or custom built solutions contact us!

Full technical description, validation, and figures: Segales, A. R., et al. (2026): The CopterSonde-SWX: a weather-sensing UAS for severe weather and high-wind planetary boundary layer profiling, Atmos. Meas. Tech., 19, 3667–3686.