The Large-Aperture Experiment to Detect the Dark Ages (LEDA) is designed to detect the spectrum of the 21 cm Hydrogen line from the Intergalactic Medium (IGM) at redshifts of 15–30, when the Universe was just ~1% of its present age.

LEDA will feature array-based calibration to improve the accuracy of foreground subtraction from the total-power signal.

The project received funding from the National Science Foundation in August 2011.

LEDA is one of several efforts seeking to study cosmological reionization and the preceding Dark Ages.

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