The Arecibo Legacy Fast ALFA Survey

Principles of ALFALFA Scheduling

The objective of ALFALFA scheduling during each observing season is to map completely, in 2 pass mode, two separate blocks of contiguous ALFALFA tiles. Each ALFALFA tile covers 4 degrees in Dec. and 20 min (5 degrees at the equator) in R.A. The Right Ascension coverage corresponds to two observing "seasons":

Given the complexities of the Arecibo telescope schedules in practice, we have mapped out a detailed plan of target drift(s) for each given observing session which tries to optimize the allocation to ALFALFA in two ways:

All of the declination settings (corresponding to Beam 0 of the ALFA) for the entire ALFALFA survey have been preset. Contiguous drifts in the 1st pass are offset from each other by 14.6'. As part of the two-pass strategy, the 2nd pass drifts are offset from the 1st by 7.3' in order to even out the scalloping.

ALFALFA Survey Status

Graphical summaries of completed and planned observations are available and are updated regularly. Just click on the links below to access them.

  • Fall 2012 observations   (in progress)
  • Completed Fall 2011 observations
  • Completed Spring 2011 observations
  • Completed Fall 2010 observations
  • Completed Spring 2010 observations
  • Completed Fall 2009 observations
  • Completed Spring 2009 observations
  • Completed Fall 2008 observations
  • Completed Spring 2008 observations
  • No observations in Fall 2007 (:
  • Completed Spring 2007 observations
  • Completed Fall 2006 observations
  • Completed Spring 2006 observations
  • Completed Fall 2005 observations
  • Completed Spring 2005 observations

    Last modified: Mon Sep 10 10:49:07 EDT 2012 by martha