Scientists are using drones to 'trick' massive radio telescopes into seeing the beginning of the universe more clearly.
April 15, 2026
Original Paper
PEACC -- Precision Emitter for 21 cm Array Coherent Calibration
arXiv · 2604.09859
The Takeaway
Mapping the 'cosmic dawn'—the time when the first stars turned on—is incredibly hard because telescopes are difficult to calibrate. This paper reveals a system called PEACC that uses a drone to fly a precise radio signal over a telescope array. Because the drone knows exactly where it is using high-precision clocks, the telescope can 'tune' itself to the drone's signal, correcting for errors. This is the first time a free-space drone has been used to calibrate these telescopes with such extreme precision. It’s like using a laser pointer to help calibrate a giant observatory, and it’s the key to finally seeing the first light in the history of the universe.
From the abstract
Foreground mitigation remains a central challenge for 21 cm intensity mapping experiments, which require precise, wideband calibration of telescope beams and gains. We present the Precision Emitter for 21 cm Array Coherent Calibration (PEACC), a digitally synthesized calibration source that generates Gaussian noise across a 1.2 GHz bandwidth, time-synchronized to a 1 pulse-per-second output from a GPS-disciplined oscillator, and optimized for aerial deployment. PEACC uses a dual-source architect