82 research outputs found
Approximation of holomorphic mappings on strongly pseudoconvex domains
Let D be a relatively compact strongly pseudoconvex domain in a Stein
manifold, and let Y be a complex manifold. We prove that the set A(D,Y),
consisting of all continuous maps from the closure of D to Y which are
holomorphic in D, is a complex Banach manifold. When D is the unit disc in C
(or any other topologically trivial strongly pseudoconvex domain in a Stein
manifold), A(D,Y) is locally modeled on the Banach space A(D,C^n)=A(D)^n with
n=dim Y. Analogous results hold for maps which are holomorphic in D and of
class C^r up to the boundary for any positive integer r. We also establish the
Oka property for sections of continuous or smooth fiber bundles over the
closure of D which are holomorphic over D and whose fiber enjoys the Convex
approximation property. The main analytic technique used in the paper is a
method of gluing holomorphic sprays over Cartan pairs in Stein manifolds, with
control up to the boundary, which was developed in our paper "Holomorphic
curves in complex manifolds" (Duke Math. J. 139 (2007), no. 2, 203--253)
Analysis of the application of the optical method to the measurements of the water vapor content in the atmosphere - Part 1: Basic concepts of the measurement technique
We retrieved the total content of the atmospheric water vapor (or Integrated
Water Vapor, IWV) from extensive sets of photometric data obtained since 1995
at Lindenberg Meteorological Observatory with star and sun photometers.
Different methods of determination of the empirical parameters that are
necessary for the retrieval are discussed. The instruments were independently
calibrated using laboratory measurements made at Pulkovo Observatory with the
VKM-100 multi-pass vacuum cell. The empirical parameters were also calculated
by the simulation of the atmospheric absorption by water vapor, using the
MODRAN-4 program package for different model atmospheres. The results are
compared to those presented in the literature, obtained with different
instruments and methods of the retrieval. The reliability of the empirical
parameters, used for the power approximation that links the water vapor content
with the observed absorption, is analyzed. Currently, the total (from
measurements, calibration, and calculations) errors yield the standard
uncertainty of about 10% in the total column water vapor. We discuss the
possibilities for improving the accuracy of calibration to ~1% as indispensable
condition in order to make it possible to use data obtained by optical
photometry as an independent reference for other methods (GPS, MW-radiometers,
lidar, etc).Comment: 28 pages, 8 figures, 3 tables. In submitting to Atmospheric
Measurement Technique
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