VLBA Phase-Referencing
نویسندگان
چکیده
منابع مشابه
Atmosphere-Corrected Phase-Referencing
One major problem of phase-referencing VLBI observations are phase errors due to the unknown tropospheric zenith delay at each antenna. These errors degrade the quality of the phase-referenced image and limit the achievable astrometric accuracy. We will present and compare two independent methods to estimate the zenith delay offset at each antenna. The zenith delay offsets can then be used to c...
متن کاملPhase-Referenced VLBA Observations of OH Masers at 4765 MHz
We report VLBA observations of maser emission from the rotationally excited Π1/2, J = 1/2 state of OH at 4765 MHz. We made phase-referenced observations of W3(OH) at both 4765 MHz and 1720 MHz and found emission in three fields within a ∼2000 AU diameter region and verified that in two of the three fields, 4765 MHz and 1720 MHz emission arise from the same position to within ∼4 mas (∼8 AU). We ...
متن کاملIn-Beam Phase Referencing with the Deep Space Network Array
The Deep Space Network Array of the future provides an intriguing possibility of using the techniques of in-beam phase referencing to determine the position of spacecraft with accuracy at the level of 0.1 nrad. In this article, we discuss the prospects for carrying out such measurements at both 8.4 GHz (X-band) and 32 GHz (Ka-band). Our study suggests that at X-band in-beam calibration may be a...
متن کاملImproved phase sensitivity in spectral domain phase microscopy using line-field illumination and self phase-referencing.
We report a quantitative phase microscope based on spectral domain optical coherence tomography and line-field illumination. The line illumination allows self phase-referencing method to reject common-mode phase noise. The quantitative phase microscope also features a separate reference arm, permitting the use of high numerical aperture (NA > 1) microscope objectives for high resolution phase m...
متن کاملASTRA: ASTrometry and phase-Referencing Astronomy on the Keck interferometer
ASTRA (ASTrometric and phase-Referencing Astronomy) is an upgrade to the existing Keck Interferometer which aims at providing new self-phase referencing (high spectral resolution observation of YSOs), dual-field phase referencing (sensitive AGN observations), and astrometric (known exoplanetary systems characterization and galactic center general relativity in strong field regime) capabilities....
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1994
ISSN: 0074-1809
DOI: 10.1017/s0074180900107387