Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of Clouds in Multiple Wind Velocity Fields using Ground-based
  Infrared Sky Images   Horizontal atmospheric wind shear causes wind velocity fields to have
different directions and speeds. In images of clouds acquired using
ground-based sky imagers, clouds may be moving in different wind layers. To
increase the performance of an intra-hour global solar irradiance forecasting
algorithm, it is important to detect multiple layers of clouds. The information
provided by a solar forecasting algorithm is necessary to optimize and schedule
the solar generation resources and storage devices in a smart grid. This
investigation studies the performance of unsupervised learning techniques when
detecting the number of cloud layers in infrared sky images. The images are
acquired using an innovative infrared sky imager mounted on a solar tracker.
Different mixture models are used to infer the distribution of the cloud
features. The optimal decision criterion to find the number of clusters in the
mixture models is analyzed and compared between different Bayesian metrics and
a sequential hidden Markov model. The motion vectors are computed using a
weighted implementation of the Lucas-Kanade algorithm. The correlations between
the cloud velocity vectors and temperatures are analyzed to find the method
that leads to the most accurate results. We have found that the sequential
hidden Markov model outperformed the detection accuracy of the Bayesian
metrics.

18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci