Phase coherence of the EVLA radio telescope

Details Phase coherence of the EVLA radio telescope Phase coherence of the EVLA radio telescope

Jul 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006spie.6267e.130d&link_type=abstract

Ground-based and Airborne Telescopes. Edited by Stepp, Larry M.. Proceedings of the SPIE, Volume 6267, pp. 62673Y (2006).

Astronomy and Astrophysics

Astronomy

Scientific paper

The design of the National Radio Astronomy Observatory's Expanded Very Large Array (EVLA) project is approaching completion. Four of the twenty-seven antennas have been upgraded into the final configuration. The 2200 miles of fiber optic cables have been installed underground and are functional. The master oscillator and the round trip phase hardware have been operating uninterrupted since November 2003. Hundreds of hours of test observations have been performed as we start the task of characterizing the upgraded system. This paper discusses the results of this testing and describes the techniques used to maintain phase coherence of the EVLA LO chain and of the new wideband receivers. The enhancements to the VLA system include a new local oscillator (LO) system, a fiber optic LO distribution system, and a digital round trip phase measurement system. The phase requirement for the LO system requires that the long term phase drift slope be less than 6.0 picoseconds per 30 minutes at 40 GHz and be maintained across the entire array. To accomplish this, a near real time continuous measurement is made of the phase delay in the fiber optic cable distributing the LO reference signals to each antenna. This information is used by the correlator to set the phase on each of the baselines in the array.

Affiliated with

Also associated with

No associations

Rating

Phase coherence of the EVLA radio telescope does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Phase coherence of the EVLA radio telescope, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase coherence of the EVLA radio telescope will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1623297