摘要
The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the most sensitive ground-based,singledish radio telescope on Earth.However,the original HⅠspectra produced by FAST are affected by standing waves.To maximize the power of FAST for high-sensitivity observations,we proposed an algorithm that combines fast Fourier transforms and extreme envelope curves to automatically correct the baselines of FAST HⅠspectra and remove standing waves from the baselines.This algorithm can reduce the amplified noise level caused by standing waves to a near-ideal level without losing signals or introducing false signals.The root mean square of the average baseline reaches~8 mK,approaching the theoretical sensitivity of an HⅠspectrum produced by FAST for an integration time of 335 minutes,i.e.,~6 m K.
基金
the National Natural Science Foundation of China(NSFC,Grant Nos.11933011 and 11873019)
the Natural Science Foundation of Jiangsu Province(Grant No.BK20210999)
the Key Laboratory for Radio Astronomy
support from the Entrepreneurship and Innovation Program of Jiangsu Province。
