Observing time estimates

Observing time estimates must take into account:

• receiver tunings,

• pointing, focus, eventually necessary receiver alignment, continuum and line calibrations,

• telescope motions when changing sources as well as dead times due to telescope motion and/or data writing between ON and OFF subscans,

• integration time on source and comparison field(s). The total integration time should be derived using the standard formula:

  

  where and are the telescope forward and main beam efficiencies, is the system temperature above the atmosphere (in the antenna temperature scale), B the channel noise bandwidth, and t the total (ON + OFF) integration time. should be estimated for an `average' winter humidity for 3mm, 2mm and 1.3mm observations (4 mm of precipitable water, or at 230 GHz) and for `good' winter conditions (1.5 mm of water, or at 345 GHz) for 0.8 mm observations.

  We ask you to specify in your proposal the parameter values ( total integration time, overheads and dead times) adopted in your calculation of the needed telescope time.

A technical report explaining how to estimate the telescope time needed to reach a given sensitivity level in various modes of observation was published in the January 1995 issue of the IRAM Newsletter [9] . You are asked to follow the guidelines given in this report (or to justify particular requirements) in your proposal.