4. Parameters of "Scan Table"

4.2 Continuum observation
    4.2.1 Common parameters
    4.2.2 Scan pattern

    4.2.1 Common parameters

    Fig 4.2.1  Scan Table Window

    File Name : Name of "Scan Table" to save.

    Scan Mode : Select a scan pattern by pushing any button.  A window to set parameters appears.

      Cross Scan : Cross scan on a source. This pattern is used for pointing.
      Raster Scan : Mapping by raster scan.

    Calibration Mode : Select calibration system for intensity calibration.
      Non : No calibration (Default).
      R-SKY : Use R-SKY calibration.

      Integration Time : Integration time of the sky and the absorber for calibration. Enter half of the integration time, for example, 8 (¡ß 2) sec.
       

    Interval : Number of repeat of the sequence defined by Scan Mode between intensity calibrations. The interval time of calibration should be 10-20 min. You should decide this parameter depending on the weather condition.
    4.2.2 Scan Pattern
     


      Fig 4.2.3  Cross Scan Window

      Observation Mode : For pointing, select pointing.

      Coordinate System : Coordinate system for scan.

      Map Position Angle : Position angle of the scan pattern on the specified coordinate system. (+ : CCW)

      Scan :

      dX0, dY0 : Coordinate of the start point of a map (not include Approach).
      Length : Length of main scan path. Approach is not included. Scan direction is defined by +/- (cf. fig 4.2.4).

      Time :

      Scan : Scan time of main scan path. Enter half of the time. Scan speed of the antenna is Scan Length/Scan Time. The typical scan speed is 10-20 arcsec/s.
      Approach : Time for acceleration. Enter half of the time.
      Transit : Transit time to start point of the next scan path.


      Number of Cycles :Number of repeat of the cycles.
       
       

      Fig 4.2.4  Scan pattern of the above Scan Table.

      • Raster Scan
      Fig 4.2.8  Raster Scan Window
      Observation Mode : Select non-pointing.

      Coordinate System : Coordinate system for scan.

      Position Angle : Position angle of a map on the specified coordinate system. (+ : CCW)

      Scan :

      dX0, dY0 : Coordinate of the start point of a map (not include Approach).
      Length : Length of one scan path. Initial direction of scan is defined by +/-.
      Spacing : Spacing between scan paths. Direction of the next scan path is defined by +/-.
      Direction : Scan direction.
      Begin-End : Numbers of start scan path and end scan path.


      Time :

      Approach : Time for accelerataion. Enter half of the time.
      Scan : Scan time of main scan path. Enter half of the time. Scan speed of the antenna is Scan Length/Scan Time. The typical scan speed is 10-20 arcsec/s.
      Transit : Transit time to move to the next scan path. Enter half of the time.
      Return : Time to return to the start point. Enter half of the time.


      Number of Maps : Number of repeat of the scan.

      Fig 4.2.9  Scan pattern of the above Scan Table.
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