This documentation teaches how to run the clearness index component of JGrass-Newage

1. Bancheri and Formetta
LINKERS
JGrass-NewAge: ClearnessIndex component
Marialaura Bancheri*†
and Giuseppe Formetta†
*
Correspondence:
marialaura.bancheri@unitn.it
Dipartimento di Ingegneria Civile
Ambientale e Meccanica, Trento,
Mesiano di Povo, Trento, IT
Full list of author information is
available at the end of the article
†
Code Author
Abstract
These pages teach how to run the clearness index (CI) component inside the OMS 3
console. Some preliminary knowledge and installation of OMS is mandatory (see @Also
useful). This component deals with the computation of the clearness index, which is the
ratio between the measured incoming solar radiation and the theoretical solar radiation
computed at the top atmosphere. The package is perfectly integrated in the
JGrass-NewAge, and it is fed by other components, like the one providing the
shortwave radiation (SWRB, (1)).
@Version:
0.1
@License:
GPL v. 3
@Inputs:
• Incoming solar radiation (W/m2
);
• theoretical solar radiation computed at the top atmosphere (W/m2
);
@Outputs:
• Clearness index (-)
@Doc Author: Marialaura Bancheri
@References:
• See References section below
Keywords: OMS; JGrass-NewAGE Component Description; clearness index

2. Bancheri and Formetta Page 2 of 5
Code Information
Executables
This link points to the jar file that, once downloaded can be used in the OMS console:
https://github.com/GEOframeOMSProjects/OMS_Project_CI/tree/master/lib
Developer Info
This link points to useful information for the developers, i.e. information about the code
internals, algorithms and the source code
https://github.com/geoframecomponents
Also useful
To run JGrass-NewAGE it is necessary to know how to use the OMS console. Information
at: ”How to install and run the OMS console”,
https://alm.engr.colostate.edu/cb/project/oms).
JGrasstools are required for preparing some input data (information at:
http://abouthydrology.blogspot.it/2012/11/udig-jgrasstools-resources-in-italian.
html
To visualize results you need a GIS. Use your preferred GIS, following its installation
instructions. To make statistics on the results, you can probably get benefits from R:
http://www.r-project.org/ and follow its installation instruction.
To whom address questions
marialaura.bancheri@unitn.it
Authors of documentation
Marialaura Bancheri (marialaura.bancheri@unitn.it)
This documentation is released under Creative Commons 4.0 Attribution International

3. Bancheri and Formetta Page 3 of 5
Component Description
The clearness index is the ratio between the measured incoming solar radiation and the
theoretical solar radiation computed at the top atmosphere. The index is needed to ac-
count for the cloudness for the simulation of the longwave radiation in all-sky conditions.
Its dimensionless values varies between [0,1].
Detailed Inputs description
General description
The input file is a .csv file containing a header and one or more time series of input data,
depending on the number of stations involved. Each column of the file is associated to a
different station.
The file must have the following header:
• The first 3 rows with general information such as the date of the creation of the file
and the author;
• the fourth and fifth rows contain the IDs of the stations (e.g. station number 8:
value 8, ID, ,8);
• the sixth row contains the information about the type of the input data (in this
case, one column with the date and one column with double values);
• the seventh row specifies the date format (YYYY-MM-dd HH:mm).
All the previous information are shown in the figure 1.
Figure 1 Heading of the .csv input file.
Measured incoming solar radiation
The measured incoming solar radiation should be given in time series or raster maps of
(W · m−2
) values for the investigated station.
Top atmosphere solar radiation
The theoretical solar radiation is computed at the top atmosphere (see (1)) and should
be given in time series or raster maps of (W · m−2
) values.
Detailed Outputs description
The output file will have exactly the same heading of the input file (see fig. 1).
Time series of the Clearness index
The Clearness index output is given as a time series at a given point or as raster maps.
The components in the two cases are different (respectively CLearnessIndexPointCase
and ClrearnessIndexRasterCase). Its units are (W · m−2
/ W · m−2
) and the values vary
between 0 and 1. During night time the values are set equal to NA. Figure 2 shows the
results of a CI simulation.

4. Bancheri and Formetta Page 4 of 5
0 5000 10000 15000 20000 25000
0.00.20.40.60.81.0
Clearness index
Time [h]
CI[-]
Figure 2 Evolution of clearness index with time: its values vary between 0 and 1
Examples
The following .sim file is customized for the use of the CI component for the point case.
import static oms3.SimBuilder.instance as OMS3
def home = oms_prj
// start and end date of the simulation
def startDate= "2004 -06 -10 00:00"
def endDate="2009 -12 -31 23:00"
OMS3.sim {
resource "$oms_prj/lib"
model(while: " reader_data_SWRB_measured .doProcess" ) {
components {
// components to be called : reader input data , CI and writer
output data
" reader_data_SWRB_measured " "org.jgrasstools.gears.io.
timedependent . OmsTimeSeriesIteratorReader "
" reader_data_SWRB_top " "org. jgrasstools .gears.io.
timedependent . OmsTimeSeriesIteratorReader "
"CI" " clearnessIndex .
ClearnessIndexPointCase "
"writer_CI" "org.jgrasstools.gears.io.
timedependent . OmsTimeSeriesIteratorWriter "
}
parameter{
// parameter of the reader components
" reader_data_SWRB_measured .file" "${home }/ data/
SWRBmeasured .csv"
" reader_data_SWRB_measured .idfield" "ID"
" reader_data_SWRB_measured .tStart" "${startDate}"
" reader_data_SWRB_measured .tEnd" "${endDate}"
" reader_data_SWRB_measured .tTimestep" 60
" reader_data_SWRB_measured .fileNovalue" " -9999"
" reader_data_SWRB_top .file" "${home }/ data/TOPATM.csv"
" reader_data_SWRB_top .idfield" "ID"
" reader_data_SWRB_top .tStart" "${startDate}"
" reader_data_SWRB_top .tEnd" "${endDate}"

5. Bancheri and Formetta Page 5 of 5
" reader_data_SWRB_top .tTimestep" 60
" reader_data_SWRB_top .fileNovalue" " -9999"
// parameter of the writing component
"writer_CI.file" "${home }/ output/CI.csv"
"writer_CI.tStart" "${startDate}"
"writer_CI.tTimestep" 60
}
connect {
" reader_data_SWRB_measured .outData" "CI.
inSWRBMeasuredValues "
" reader_data_SWRB_top .outData" "CI.
inSWRBTopATMValues "
" vreader_station .geodata" "CI.inStations"
"CI.outCIHM" "writer_CI.inData"
}
}
}
The .sim file can be downloaded from here:
https://github.com/GEOframeOMSProjects/OMS_Project_CI/tree/master/simulation
Data and Project
The following link is for the download of the input data necessaries to execute the CI
component (as shown in the .sim file in the previous section ) :
https://github.com/GEOframeOMSProjects/OMS_Project_CI/tree/master/data
The following link is for the download of the OMS project for the CI component:
https://github.com/GEOframeOMSProjects/OMS_Project_CI
%
References
1. Formetta, G., Rigon, R., Ch´avez, J., David, O.: Modeling shortwave solar radiation using the jgrass-newage system.
Geoscientific Model Development 6(4), 915–928 (2013)