18 citations · 24 across the 5 of their papers we have counts for
6 papers · 2 filters
On the way to global phase-delay astrometry
E. Ros, J. M. Marcaide, J. C. Guirado +1
The use of the phase-delay improves substantially the accuracy obtained in VLBI astrometry with respect to the group-delay observable. Recently, Ros et al. (1999) have extended the…
VLBI imaging of the gravitational lens MGJ0414+0534
E. Ros, J. C. Guirado, J. M. Marcaide +5
We observed the quadruple gravitationally lensed image of MGJ0414+0534 on 23 November 1997 with a global VLBI array at 8.4 GHz. We report wide-field imaging results of its four com…
The complete S5 polar cap sample: en route to phase-delay global astrometry
E. Ros, J. M. Marcaide, J. C. Guirado +1
We report on the present status of our S5 polar cap phase-connected astrometry program. We observe 13 radio sources in the northernmost 20deg of the sky at the wavelengths of 3.6cm…
Towards global-phase-delay VLBI astrometry: observations of QSO 1150+812 and BL 1803+784
M. A. Perez-Torres, J. M. Marcaide, J. C. Guirado +4
On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15°apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using…
VLBI difference astrometry at 43GHz
J. C. Guirado, J. M. Marcaide, M. A. Perez-Torres +1
From 43GHz VLBA observations of the pair of radio sources 1928+738 and 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at…
A GPS-based method to model the plasma effects in VLBI observations
E. Ros, J. M. Marcaide, J. C. Guirado +2
Global Positioning System (GPS) satellites broadcast at frequencies of 1,575.42 MHz (L1) and of 1,227.60 MHz (L2). The dispersive property of the ionosphere can be used to combine…