Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atmospheric dispersion and the implications for phase calibration   The success of any ALMA phase-calibration strategy, which incorporates phase
transfer, depends on a good understanding of how the atmospheric path delay
changes with frequency (e.g. Holdaway & Pardo 2001). We explore how the wet
dispersive path delay varies for realistic atmospheric conditions at the ALMA
site using the ATM transmission code. We find the wet dispersive path delay
becomes a significant fraction (>5 per cent) of the non-dispersive delay for
the high-frequency ALMA bands (>160 GHz, Bands 5 to 10). Additionally, the
variation in dispersive path delay across ALMA's 4-GHz contiguous bandwidth is
not significant except in Bands 9 and 10. The ratio of dispersive path delay to
total column of water vapour does not vary significantly for typical amounts of
water vapour, water vapour scale heights and ground pressures above Chajnantor.
However, the temperature profile and particularly the ground-level temperature
are more important. Given the likely constraints from ALMA's ancillary
calibration devices, the uncertainty on the dispersive-path scaling will be
around 2 per cent in the worst case and should contribute about 1 per cent
overall to the wet path fluctuations at the highest frequencies.

24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
30
The categories of this paper are: q-alg