LABOCA observing time calculator, Ver 3.3

You can either calculate the RMS for a given integration time, or calculate the integration time needed to reach a certain RMS.

The mean point-source sensitivity of the array, determined from on-sky integrations, is 60 mJy sqrt(s). This value is achieved only by filtering the low frequencies (hence large scale emission) to reject residual sky-noise. Without low frequency filtering the observations become sensitive to extended emission at the cost of the mean array sensitivity increasing to 100 mJy sqrt(s). The proper value is selected based on if "Point source(s)" or "Extended source(s)" is checked.

Scanning area should correspond to the area covered by the scanning pattern. For a single point source, this value should be set to 0. Note that the unit is square arc minutes (arcmin²).

The calculated integration time does not include any overhead times. This overhead includes setup, target acquisition, software setup, data transfer time (writing the FITS file), telescope slewing time, and calibrations (skydips, focus, pointings and flux calibration). In order to facilitate the calculation of the total observing time needed to achive a certain goal in rms noise, a time calculation including an avarage combined overhead of 65% is also presented by the observing time calculator.

A default PWV of 1.0 mm is proposed. You can change this value below (this value corresponds to a line-of-sight opacity of 0.373 at an elevation of 60 degrees).

Since July 2016 LABOCA photometry mode is not offered anymore due to unreliable performance

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Calculate RMS Point source(s) Extended source(s) Scanning area (arcmin2): Integration time (seconds): Elevation (degrees): PWV [<3](mm):

Calculate Integration time Point source(s) Extended source(s) Scanning area (arcmin2): RMS (mJy/beam): Elevation (degrees): PWV [<3](mm):

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Version history

• Version 1.0: Based on the experience in the science verification.
• Version 2.0: Based on observations. Adding wobbler on-off and mode and possibility to change elevation
• Version 3.0: Adding the possibilty to change the PWV.
• Version 3.1: The RMS obtainded in wobbler mode has been updated, based on data accumulated over the years.
• Version 3.2: Updated the number of working bolometers in 2015.
• Version 3.2.1: (2016-07-01) Photometry mode not offered anymore due to unreliable performance.
• Version 3.3: (2017-03-01) Updated number of working bolometers and NEFD according to instrument status.