Raw voltage data recorded at a single pod of the 21CMA (21 Centimeter Array) on 15 April 2025

The data consist of low-Earth-orbit (LEO) satellite observations acquired on 15 April 2025 using a single pod of the 21 Centimeter Array (21CMA), with a fixed pointing toward the North Celestial Pole. The observations are designed to detect unintentional low-frequency electromagnetic emissions from LEO satellites, such as Starlink.

Data acquisition started at 19:40 Beijing Time (UTC+8) on 15 April 2025. The signals were recorded in the form of raw voltage binary data, with a sampling rate of 480 MHz and a sampling precision of 16-bit signed integers. By applying Fourier transforms with different FFT lengths, the time and frequency resolutions of the data products can be flexibly adjusted.