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Enter the control and performance parameters

The final technical specifications of your Science Goal are entered in the Control and Performance panel (see Fig. 3.8). The Configuration Information section displays information on the array configurations planned for Cycle 1, and uses the representative frequency defined in the spectral setup to calculate the Synthesized beamsize and the Maximum recoverable scale of the observations.

In the Desired Performance section you can define and check technical details of the observations using the following fields (fields displayed in red must be filled):

Desired Angular Resolution: your choice should be guided by the synthesized beamsizes corresponding to the most compact and most extended configurations available in Cycle 1 as displayed in the Configuration Information. The value entered cannot be smaller than the synthesized beam size of the most extended configuration, and cannot be larger than twice the synthesized beam size of the most compact configuration. You can input the angular resolution in arc-seconds or a fraction of the main beam size.
Largest Angular Scale in source: select whether you are observing a point source or an extended source. For the latter choice you will be prompted to specify the largest expected angular scale. Together with the angular resolution, this will be used to define the array configuration(s) necessary to achieve your scientific goals. The input units are the same as for the angular resolution.
Desired sensitivity per pointing: you should enter the sensitivity required for the most restrictive line/continuum observation to achieve the scientific aims of the Science Goal, and if relevant mention the sensitivity for the remaining lines/continuum in the technical justification. In the case of a rectangular field mosaic you should specify the sensitivity required over the mosaic, not that for individual overlapping pointings.
Bandwidth used for Sensitivity: for continuum observations, this field is automatically set to AggregateBandwidth. For spectral line observations, you can pick one of four choices given in the dropdown menu:

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AggregrateBandwidth: the sensitivity calculation will be performed for the summed bandwidth of all your selected spectral windows
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LargestWindowBandwidth: the bandwidth of your widest spectral window is used to perform the sensitivity calculation
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FinestResolution: the sensitivity calculation is performed for the Hanning smoothed spectral resolution of your observation
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User: the sensitivity calculation is performed for a bandwidth of your choice, which is useful if you are intending to smooth your data after observation to achieve a certain S/N.

Do you request complementary ACA observations: based on your previous input, the OT will make a recommendation on whether you need additional ACA observations if you press the Suggest button. You can choose to override the recommendation of the OT, but should carefully justify your choice in the technical justification.
Science goal integration time estimate: The Time Estimate button will estimate the total time required to achieve the desired sensitivity goal on the 12m antennas, including calibrations, multiple pointings, and overheads. ACA and Total Power observations are estimated to require a factor of three more time than the 12-m array observations. It is the time computed here that is displayed on the front page of your proposal and will be used by the observatory as an estimate of how long your project will take to complete. Note that, for Cycle 1, proposals requiring more than 100 hours cannot be submitted.
Does your setup need more time than is indicated by the time estimate? If the time required to reach your scientific objective is not driven purely by sensitivity, but by other factors such monitoring requirements, this should be indicated here and carefully justified in the technical justification.
Is this observing time constrained? The OT currently has the facility to capture simple time constraints using a calendar tool (see Fig. 3.8). Other relevant timing information can be entered in the free-format text box.

Figure 3.8: Control and Performance editor pane.
Image Img09

You can use the Sensitivity Calculator button in the Toolbar to bring up a pop-up window (see Fig. 3.9) that allows you to experiment with the integration time estimated to achieve a given sensitivity for a given setup. By default, the setup is appropriate for Cycle 1 capabilities. Note that any parameters entered here are not reflected in the Control and Performance page. The integration time computed from the Sensitivity Calculator refers to just one pointing for the science target and does not take into account calibrations or other overheads.

Figure 3.9: Sensitivity Calculator.
Image Img10


next up previous contents
Next: Validate your project Up: Proposal creation and submission Previous: Select the calibration strategy   Contents
The ALMA OT Team, 2013 Feb 27