Exercises related to the ALFALFA observing
memo we wrote on ALFA beam rotation.
Suppose the ALFALFA schedule for a given day
targets the drift at +28d35'30"; therefore, the central beam
(designated Beam "0") is the one
which is set to declination of +28d35'30".
- What is the zenith angle of this drift as observed with ALFA beam
- At what azimuth will we orient the azimuth arm so that ALFA
can observe this declination strip?
- List the resultant seven declinations covered by
the seven beams, in order, from south to north.
- Assuming a mean effective HPBW of the telescope at 1.4 GHz
(the frequency of the HI line) is about 3.5 arcminutes, how long does
it take for a source to traverse the beam?
Last modified: Sun Oct 7 09:41:14 EST 2007 by martha