About the project

MASK Sample

KVNCS: KVN Calibrator Survey (1553)

Known K-band calibrators (837)[1]

KVN K-band fringe survey sources (426)

MASK sources for the pilot observations (153)

Simultaneous Multi-Freuqency VLBI Catalog of AGNs at 22/43/86/130GHz

Most of AGNs are variable on time scales
Simultaneous multi-frequencies observations will be able to provide important clues on physical conditions of AGNs, especially in particular central regions of compact systems
MASK will address the subjects of General and lasting importance to the broad astronomical community with KVN data yielding a substantial and coherent database
Enabling timely and effective opportunities for follow-on observations and for archival research

KVN Multi-Frequency Receiving System & Frequency Phase Transfer (FPT)

The basic idea of frequency phase transfer (FPT) is to use fringe phase solutions at the lower frequency for compensating visibility phases at higher frequencies, based on the non-dispersive characteristics of atmosphere to the radio system as shown in the upper plots. The superiority of FPT on the atmospheric phase calibration is clearly demonstrated in the lower plots, showing a phase coherence nearly close to 1 and Allan standard deviation (ASD) reduced by order of one magnitude.