Abstract The Event Horizon Telescope (EHT) is a very long-baseline interferometer built to image supermassive black holes on event-horizon scales. In this paper, we investigate candidate sites for an expanded EHT array with improved imaging capabilities. We use historical meteorology and radiative transfer analysis evaluate site performance. Most of the existing in have median zenith opacity le...

At present spacecraft angular position with the Deep Space Network (DSN) is determined using group delay estimates from very long baseline interferometry (VLBI) phase measurements employing differential one-way ranging (DOR) tones. Group delay measurements require high signal-to-noise ratio (SNR) to provide modest angular position accuracy. On the other hand, VLBI phases with modest SNR can be ...

Atom-interferometer gravitational-wave (GW) observatory, as a new design of ground-based GW detector for the near future, is sensitive at relatively low frequency observations. Taking proposed atom interferometer Zhaoshan Long-baseline Atom Interferometer Gravitation Antenna (ZAIGA), and its illustrative upgrade (Z+) examples, we investigate how will complement laser interferometers in testing ...

Narrow-angle astrometry with long-baseline infrared interferometers can provide extremely Klgh accuracies as required for indirect planet detection. Narrow-angle astrometric interferom~ try exploits the propertim of atmospheric turbulence over fieldn smaller than the interferometer bmeline divided by the atmospheric scale height. For such fields, wcuracy is linear with star separation, and near...