Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Methods Of Measurement The Three-Dimensional Wind Waves Spectra, Based
  On The Processing Of Video Images Of The Sea Surface   Optical instruments for measuring surface-wave characteristics provide a
better spatial and temporal resolution than other methods, but they face
difficulties while converting the results of indirect measurements into
absolute levels of the waves. We have solved this problem to some extent. In
this paper, we propose an optical method for measuring the 3D power spectral
density of the surface waves and spatio-temporal samples of the wave profiles.
The method involves, first, synchronous recording of the brightness field over
a patch of a rough surface and measurement of surface oscillations at one or
more points and, second, filtering of the spatial image spectrum. Filter
parameters are chosen to maximize the correlation of the surface oscillations
recovered and measured at one or two points. In addition to the measurement
procedure, the paper provides experimental results of measuring
multidimensional spectra of roughness, which generally agree with theoretical
expectations and the results of other authors.

28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg