Observing time estimates

Observing time estimates must take into account:

• integration time on source and comparison field(s), including overheads for ON/OFF telescope motions, deadtime for device switching and data transfer.
• pointing, focus, continuum and line calibrations
• telescope slew motions
• receiver tunings (for heterodyne observations),

For bolometer observations, integration time estimators are available in the NIC software [11]. For heterodyne observations, the total integration time should be derived using the standard radiometer 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 in Hz, and t the total (ON + OFF) integration time in seconds. For 3, 2, and 1.3mm observations, should be estimated for average winter conditions (4 mm of precipitable water, or at 230 GHz). Proposals for 0.8mm should adopt good winter conditions (1.5 mm of water, or at 345 GHz).

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]. It has been included in the 30-m telescope Manual [10]. You are asked to follow the guidelines given in this report (or to justify particular requirements) in your proposal.