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Some measures conducted at the MRT (30 m telescope) to characterize the sky noise anomalous refraction.

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Presentation on theme: "Some measures conducted at the MRT (30 m telescope) to characterize the sky noise anomalous refraction."— Presentation transcript:

1 Some measures conducted at the MRT (30 m telescope) to characterize the sky noise anomalous refraction

2 Anomalous refraction measurements [J.Peñalver] 2 seconds between each point

3 Anomalous refraction measurements [J.Peñalver] 2 seconds between each point => anomalous refraction may move pointing faster than traditional jiggling used to compensate for it...

4 Anomalous refraction measurements [J.Peñalver] 2 seconds between each point

5 The wobbler is always used with a period of 0.52sec (freq. ~1.923Hz), i.e. with a "phase time" of 260msec and a blanking time of 40msec => integration time per wobbler phase = 220msec. The plots show the percentage of time the noise in the data is below the value on the x-axes. In red is the noise in the orig. data (the "phases"), in green in the chopped data (the "phase difference"). The % numbers in green show the percentage of observing time, the chopped data have noise = sqrt(2)*noise on absorber, (sky noise = noise on absorber). In other words: if the noise in the data is < sqrt(2)*noise on absorber (=60mJy/0.52sec), we are "bolo. noise dominated". Sky Noise [R.Zylka] The plots show the cumulative weather statistics during MAMBO2 observations.

6 The plots show the "anomalous refraction" for the winters 2003/04+2004/05 (i.e. with the OCS) as determined using the pointing scans with MAMBO2. The rms values are ~1.7arcsec Sky Noise [R.Zylka]

7 The plots show the "anomalous refraction" as determined using the pointings with het. receivers @1.2mm in winter (2007.11.01 till 2008.03.31, the decimal fraction is the scan #) Sky Noise [R.Zylka]

8 The plots show the "anomalous refraction" as determined using the pointings with het. receivers @1.2mm in "summer" (2008.04.01 till 2008.08.31). Sky Noise [R.Zylka]


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