UV_TRACK_PHASE

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UV_TRACK_PHASE

        UV_TRACK_PHASE  simulates the uv coverage of an observation specified by
        the source, observatory, and hour angle range. The output is a uv  table
        that  can be used as input for tasks such as UV_FMODEL. Caution: this uv
        table is not standard, as it includes two addition columns (#11 with el-
        evation, #12 with integration time).

        The  weight  column  (#10) is filled with as realistic as possible esti-
        mates of the actual weights (derived from Trec, Tau, elevation).

        The visibilities columns (#8 and #9) are filled with a point source (am-
        plitude  =  1,  phase = 0). Random phase noise can be added, to simulate
        atmospheric phase noise.

        If DO_SCREEN = YES, a phase screen is used to simulate phase noise: this
        file  contains a statistically correct spatial distribution of the phase
        perturbation induced by the atmopshere. This screen moves above the  ar-
        ray  at  the wind velocity. The correct phase value is computed each an-
        tenna at each time dump.

        If DO_CALIB = YES, the observations of a calibrator are  simulated,  as-
        suming  a loop calibrator-source-calibrator-source. The corresponding uv
        table is created.

        If DO_RADIOM = YES, a phase correction based on WVR measurements is sim-
        ulated.

        UV_TRACK family of tasks (in order of increasing complexity):

            - UV_TRACK: uv coverage + random phase noise
            - UV_TRACK_PHASE: phase noise from atmospheric screen + observations
              of calibrator +  WVR correction
            - UV_OBSERVE: also includes amplitude noise
            - UV_OBSERVE_NEW: also includes anomalous refraction