Heliosat
Project - Software
Software
is written in C for a Unix station and is made of libraries.
A
document (November
2002, revision February 2004) describes the various libraries
and procedures for Heliosat-2. It provides also the equations
used in the libraries as well as bibliographical references.
It describes how these can be implemented for the correct execution
of the whole method. The procedures described here comprise
I/O orders that are to be tailored to the specific format for
Meteosat images. The
method can be applied to other geostationary satellites offering
similar broadband in the visible range (0.4 - 1.1 mm). The
input images are geometrically superimposable images. Calibration coefficients
exist that convert digital counts into radiances (W m-2 sr-1).
Two
libraries are available
- the
ESRA clear-sky model
- all
libraries for the method Heliosat-2,
including those relating to the solar geometry, clear sky
and Meteosat images (up to Meteosat-7 included)
The
ESRA clear-sky model
A
library in C for computing the irradiance / irradiation available
at ground level under clear skies. The ESRA model is named model5
in this library. The library "csmodels_lib.c"
comprises the following items:
- computation
of the Rayleigh optical depth, depending on various models,
- computation
of the Linke turbidity factor, depending on various models.
- clear
sky beam transmittance and angular function for beam radiation,
- clear
sky diffuse transmittance and angular function for diffuse
radiation,
- clear
sky irradiance (power) or irradiation (energy), as well as
the direct, beam and diffuse components, for any instant,
any duration,
- same
quantities, but averaged over a month or a year.
An
execution of the code is possible through the SoDa service to check the correct implementation.
The
ESRA clear-sky model, which is also used in the method Heliosat-2,
requests the knowledge at each geographical site of the elevation
and the Linke turbidity factor. If necessary, both databases
can be obtained at: Les Presses, Ecole des Mines de Paris.
Contact Mrs.
Silvia Dekorsy.
The coverage is worldwide.
Software
for Heliosat-2
A
set of libraries (zip format)
in C for implementing the method Heliosat-2. This set includes
the libraries relating to the solar geometry, clear sky and
Meteosat images (up to Meteosat-7 included).
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