Last Update: 25th December 2018


[General Instruction] | Introduction: 'nobs' | Project Tab |
[Line Observation] | Source Tab (Line) | Reference Tab (Line) | Scan Tab (Line) | Device Tab (Line) |
[Continuum Observation] | Source Tab (Cont.) | Reference Tab (Cont.) | Scan Tab (Cont.) | Device Tab (Cont.) |

Reference Tab (Line)

The Reference table is a newly-introduced table, which describes how to subtract noises from atmosphere and instruments. When we observe any target, a receiver outputs a summation of power throughout the path from the line-of-sight: the emission of the target and noises from the atmosphere and instruments including the radio telescope itself. In order to derive the emission of the target, there are two ways to subtraction of the noise. One is a position-switch method, the other is a frequency-switch method. For the 2018-2019 observing season, a frequency-switch method is NOT implemented on the nobs.

nobs: Reference Tab

Reference Table [mandatory field]

This field defines a name for the reference table. The file will be saved in your working directory, which is as same as 'Project' you entered at the Project tab. For example, your account ID, project name, and a name of the reference table are 'newobs', 'proj1', and 'ref1', respectively, your file is saved in

/home/newobs/proj1/obstable/

with a name of 'ref1.nreference'.

As other tables, a filename should follow the rules described below:

NOTE: You can save the input parameters anytime you want (the nobs allows you to save the reference table even if some mandatory fields still blank). The nobs does not check whether these input parameters follow the rules at that time.

Note (optional)

You can use this space to write any note about the reference table. A character limit is 100, and a line break is prohibited.

Reference Mode [fixed field]

It is needed to observe blank-sky (i.e., an emission-free region of the sky) that is close to the target, whose condition can be regarded as same as the atmosphere at the target, and subtract the blank-sky data from the target data. This position of the 'blank-sky' is called as an 'off-position'. Current nobs implement only 'position-switch' mode.

Position-Switch mode

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Recommended Setup for a Pointing Observation

For a pointing observation with a SiO maser (both for 43 GHz and 86 GHz), we recommend to use the following parameters:

  1. Reference Mode: Position-Switch mode
  2. Position Type: Offset from the source position
  3. Coordinate System: Horizontal
  4. Offset dx: 0 3 0
  5. Offset dy: 0 0 0

If you observe H2O maser at 22 GHz for checking pointing accuracy, the same parameters are recommended except for 'Offset dx' of '0 3 0' but '0 6 0'.


[General Instruction] | Introduction: 'nobs' | Project Tab |
[Line Observation] | Source Tab (Line) | Reference Tab (Line) | Scan Tab (Line) | Device Tab (Line) |
[Continuum Observation] | Source Tab (Cont.) | Reference Tab (Cont.) | Scan Tab (Cont.) | Device Tab (Cont.) |