Dotterel has developed a unique audio system. It uses an array of small microphones and a new processing algorithm for end-fire beams. Dynamic adjustable beam widths can be focused on the target, while rejecting off-axis noise including noise from the drone itself.
The on-board DSP unit runs our proprietary algorithm to filter the incoming audio to remove drone noise. This audio is streamed to a ground station in real-time for immediate use. Recorded raw files can also be post-processed to extract audio using additional methods. Overall performance is optimised for voice frequency ranges.
Impact on flight time is minimised through the use of low weight and low power design with embedded code and hardware.
A speaker with a real-time link to the groundstation is a configured option. The speaker and microphone can be used together for one-to-one or one-to-many conversations, as well as playing back pre-recorded files.
Our products also come with an independent wireless transceiver link. The standard range between the UAV and the ground station is kilometres on ISM and licensed bands. Options are available for radio transmission.
Dotterel's noise reduction and safety shrouds reduce noise created through the complex interaction of many mechanisms. First the noise created by the propeller is reduced, then remaining noise is reflected up, away from people below, and specific tonal frequencies are absorbed in the core made from a protected laminate of acoustic materials.
Shrouds are modelled and performance simulated to meet specific requirements. The shrouds increase thrust to offset some of their weight penalty. The thrust, weight, flight maneuverability objectives, along with motors, controllers, and frame design are all factored into final shroud and propeller designs.
Shrouds can be retrofitted though performance is improved if they are designed in from the start. We work with UAV manufacturers to meet solution objectives and optimise the design.
We also collaborate extensively on exploring new challenges in the field. Working with customers, external researchers and academic institutions to keep at the forefront of noise reduction.