The Phased Array Feed(PAF)is considered as one of the next generation receivers for radio telescopes,which can significantly enlarge the instantaneous Field-of-View of large aperture single dish radio telescopes and e...The Phased Array Feed(PAF)is considered as one of the next generation receivers for radio telescopes,which can significantly enlarge the instantaneous Field-of-View of large aperture single dish radio telescopes and enable more flexible observing configurations.Study efforts on PAF development for radio telescopes have been made for more than two decades and have become more and more applicable.We report the development of an ambient-temperature 19 element L-band PAF system and the experimental results including its far field beam pattern and system temperature measurement,which achieve the expectations.Implementing the aperture array beam-forming method,we demonstrate a wide-field Galactic HI observations in the radio camera mode.The results indicate that this system might be applicable for strong Galactic transient detections.This system could be directly equipped to large telescopes like the Five-hundred-meter Aperture Spherical radio Telescope(FAST)and FAST array in the future.展开更多
We generalize a previously proposed imaging scheme to situations for which the set of hidden objects embedded in the highly scattering medium can take arbitrary shapes.We compare the accuracy of images obtained from o...We generalize a previously proposed imaging scheme to situations for which the set of hidden objects embedded in the highly scattering medium can take arbitrary shapes.We compare the accuracy of images obtained from optical detection fibers with those from a ccd camera.The latter approach is more efficient and can be applied to non-contact geometries,but it requires an a priori linearization of the obtained digitized images.We discuss some details of this calibration for the camera and establish its potential as a new tool for decomposition based imaging.展开更多
基金supported by the National Key R&D Program of China under grant No.2018YFA0404703the Open Project Program of the Key Laboratory of FAST,NAOC,Chinese Academy of Sciences。
文摘The Phased Array Feed(PAF)is considered as one of the next generation receivers for radio telescopes,which can significantly enlarge the instantaneous Field-of-View of large aperture single dish radio telescopes and enable more flexible observing configurations.Study efforts on PAF development for radio telescopes have been made for more than two decades and have become more and more applicable.We report the development of an ambient-temperature 19 element L-band PAF system and the experimental results including its far field beam pattern and system temperature measurement,which achieve the expectations.Implementing the aperture array beam-forming method,we demonstrate a wide-field Galactic HI observations in the radio camera mode.The results indicate that this system might be applicable for strong Galactic transient detections.This system could be directly equipped to large telescopes like the Five-hundred-meter Aperture Spherical radio Telescope(FAST)and FAST array in the future.
文摘We generalize a previously proposed imaging scheme to situations for which the set of hidden objects embedded in the highly scattering medium can take arbitrary shapes.We compare the accuracy of images obtained from optical detection fibers with those from a ccd camera.The latter approach is more efficient and can be applied to non-contact geometries,but it requires an a priori linearization of the obtained digitized images.We discuss some details of this calibration for the camera and establish its potential as a new tool for decomposition based imaging.
