Extended Data Figure 5: Calibration parameter solutions.
From: An absorption profile centred at 78 megahertz in the sky-averaged spectrum
a–g, Solutions for the low-1 receiver at its fixed 25 °C operating temperature. It was calibrated on three occasions spanning two years, bracketing all of the low-1 observations reported. The first calibration was in August 2015 before commencing cases H1 and H2 (solid), the next was in May 2017 before H3 (dotted), and the final was in September 2017 after the conclusion of H3 (dashed). h–n, Solutions for the low-2 receiver controlled to three different temperatures: 15 °C (blue), 25 °C (black) and 35 °C (red). The parameters C1 and C2 are scale and offset factors, respectively; TC, TS and TU are noise-wave parameters (TS is not the spin temperature here; see ref. 34 for details); S11 is the LNA input reflection coefficient.
