LISSAJOUS

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LISSAJOUS

        LISSAJOUS    xAmplitude   yAmplitude
          /CENTER    xCenter      yCenter
          /FREQUENCY frequencyX   frequencyY
          /PHASES    phiX         phiY
          /TOTF      tOtf
          /SYSTEM    system

        additionally for NIKA:

          /FOCUS     f1 f2 [... f18] [direction]
          /POINTING  [yes|no]
          /TUNE      xOffsetT     yOffsetT
          /TTUNE     tTune

        Specify an On-The-Fly (OTF) map with a Lissajous curve in 1 subscan.
        LISSAJOUS is at this time (2014-11-10) supported only for GISMO and NIKA

        Real      :: xAmplitude        ! amplitude for x-offsets
        Real      :: yAmplitude        ! amplitude for y-offsets
        Real      :: xCenter           ! center x-offset
        Real      :: yCenter           ! center y-offset
        Real      :: frequencyX        ! frequency    [Hz]  for x
        Real      :: frequencyY        ! frequency    [Hz]  for y
        Real      :: phiX              ! phase offset [rad] for x
        Real      :: phiY              ! phase offset [rad] for y

        Real      :: tOtf              ! time [s]
        Character :: systemName        ! name of system, one of:
                                       ! PROJECTION
                                       ! TRUEHORIZON

        Real      :: f1 f2 [... f18]   ! focus offset [mm] during each Lissajous cur
        Character :: direction         ! direction of focus offsets, one of:
                                       ! X
                                       ! Y
                                       ! Z

        Real      :: xOffsetT          ! x-offset for tune subscan
        Real      :: yOffsetT          ! y-offset for tune subscan
        Real      :: tTune             ! time [s] for tune subscan

        During a Lissajous OTF segment, the position offsets
        x and y as a function of time t are:

        x = xCenter + xAmplitude * SIN(2 Pi frequencyX t + phiX)
        y = yCenter + yAmplitude * SIN(2 Pi frequencyY t + phiY)

        SIN is the usual sine function, Pi is the number Pi.

        xAmplitude yAmplitude xCenter yCenter are in angle units ([arc sec])
        frequencyX frequencyY                 are in [Hz]
        phiX       phiY                       are in [rad]

        Note that the possible frequencies are very low,
        typically 0.01 to 0.15 Hz.

        At the start of a Lissajous subscan, paKo will insert a "ramp" along a
        straight line, i.e., a linear OTF segment, increasing the count of
        segments by 2.  This ramp up starts with speed 0 relative to the
        source and joins smoothly with the start position and velocity of the
        Lissajous segment.  The purpose is to avoid a sudden acceleration at
        the start of the Lissajous segment.  The inserted ramp up
        segment and the Lissajous segment become part of the same subscan.

        Lissajous curves with large amplitudes or frequencies can reach the
        antenna's speed and acceleration limits for tracking.  Lissajous
        curves can be executed only for elevations less than a maximum, which
        depends on the Lissajous parameters.  For information, this elevation
        condition is shown by pako. Even below the limits, during very fast
        Lissajous curves the tracking errors will be higher, several arc sec,
        than during most other observations.

        DO NOT TRY TO OBSERVE LISSAJOUS ABOVE THIS MAXIMUM ELEVATION.

Subsections

- LISSAJOUS /CENTER
- LISSAJOUS /FREQUENCY
- LISSAJOUS /PHASES
- LISSAJOUS /SYSTEM
- LISSAJOUS /TOTF
- LISSAJOUS /FOCUS
- LISSAJOUS /POINTING
- LISSAJOUS /TUNE
- LISSAJOUS /TTUNE