For any two-axis “gimbal” mount, the basic a priori model consists of seven terms: two encoder index errors, two non-perpendicularities, two azimuth-axis tilt components, and Hooke’s Law ﬂexure.
Evaluation of the ALMA Prototype Antennas
The mean radiometrically-inferred (solid black) and mean azimuth (cyan dashed) and elevation (purple dashed) encoder pointing errors as a function of time since the start of the 1.5 deg fast switching slew are shown.
Evaluation of the ALMA Prototype Antennas
Azimuth encoder errors were converted to cross-elevation errors through multiplication with the cosine of the elevation.
Study of the Dynamics of Large Reflector Antennas with Accelerometers
For analysis of the antenna pointing and the understanding of the pointing model it is useful to know which part of the azimuth axis pointing error is due to the azimuth bearing.
Mechanical Measurements of the ALMA Prototype Antennas
In the speciﬁc example of the observation of the disk around AB Aur by AEOS telescope (Oppenheimer et al. 2008), Jang-Condell and Kuchner (2010) estimate that the error is typically at the level of ∼ 20% by ﬁtting the intrinsic azimuthal variation by a certain ﬁtting function and by calculating the rms deviation.
The Structure of a Self-Gravitating Protoplanetary Disk and its Implications to Direct Imaging Observations
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