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.

      On-Source (center) : Observe the coordinate of a source defined in Source Table. This is not ON-OFF scan.
      Cross Scan : Cross scan on a source. This pattern is used for pointing.
      Five Points : Observe 5 (or 9) points like a cross. The center is the coordinate of a source defined in Source Table.
      On-Off Scan : Random positions.  Coordinates of 20 ON positions can be defined.
      Raster Scan : Mapping by raster scan.
      Radial Scan : Radial scan on a source. The center is the coordinate of a source defined in Source Table.
    Calibration Mode : Select calibration system for intensity calibration.
      LD1-SKY : Default
      Non : No calibration

      Integration Time : Integration time of the sky and the absorber for calibration. Enter half of the integration time. Default value is 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 4.2.2  On-Source (center) Window
    Coordinate System : Coordinate system for ON position.

    Sequence Time : Integration time of ON position.

    Number of Sequences : Number of sequences.


    Fig 4.2.3  Cross Scan Window

    Observation Mode : For pointing, select pointing.

    Coordinate System : Coordinate system for scan.
                (XSUN_A, YSUN_A) :
              (XSUN_D, YSUN_D) :

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

    Scan 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. Scan speed of the antenna is Scan Length/Scan Time. The typical scan speed is 10-20"/s.
    Approach : Time for acceleration.
    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.

    Fig 4.2.5  Five Points Scan Window
    Observation Mode : Select non-pointing.

    Coordinate System : Coordinate system for ON positions.

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

    Number of Positions : Number of ON positions. Since the center is observed twice in one cycle, total numbers of ON positions are 6 for 5 points and 10 for 9 points.

    Grid Spacing 1 : Position offset (of the inner points for 9 points) from the center.

    Grid Spacing 2 (for 9 points) : Position offset of the outer points from the center.

    Off Position : Offset value of OFF position from the center.

    Time :

    On-Position : Integration time of ON position.
    Margin : Margin time before integration.
    Transit : Transit time to move to the next ON position.


    Number of Cycles : Number of repeat of the cycle.

    Fig 4.2.6  Scan pattern of the above Scan Table.

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