net.simplace.sim.transformers.AstronomicParametersTransformer
Calculated daylength, photoperiodic daylength, solar constant and
daily total effective solar height for each DOY for a set of given latitudes.
For each row in the resource it creates 366 rows containing values for
each day of year (DOY)
The transformer needs the field names of a resource, that contain
- location id
- latitude in decimal degrees
- inclination of sun angle in decimal degrees
Normally you do not enter the numeric value for latitude, but a reference to the
value, i. e. the column name of the resource's column containing the latitudes.
It outputs a resource with following fields
- DOY (serves as a key) (INT)
- location id (serves as a key, same as the key of the resource)
- daylength (DOUBLE)
- photoperiodic daylength (DOUBLE)
- solar constant (DOUBLE)
- seasonal offset of sine of solar height (DOUBLE)
- amplitude of sine of solar height (DOUBLE)
- daily integral of SINB over the day (DOUBLE)
- daily integral of corrected SINB for lower atmospheric transmission at lower solar elevation (DOUBLE)
- area under the sinBeta curve (DOUBLE)
Example
First you need a resource that has a latitude and sun inclination column.
| <resource id="locations" interface="locationsfile" frequence="COMPLEX" rule="${DefaultManagement.DoSow}">
| <header>
| <res id="LocationId" datatype="CHAR" key="vActualLocation" />
| <res id="Altitude" datatype="DOUBLE" />
| <res id="Latitude" datatype="DOUBLE" />
| <res id="SunInclination" datatype="DOUBLE" />
| <res id="SoilType" description="" datatype="CHAR" />
| </header>
| </resource>
Now the resource id="locations" has to be written into the transformers resource attribute.
The header section contains the outputs of the tranformer. Make sure that they are in the same
order as in the example. Dont't forget to add to the second element (LocationId) the same
key attribute as in the resource.
Finally you tell the transformer the name of the resources id field (LocationId) and the name
of the fields that hold the latitude and sun inclination.
Remember: the names have to match exactly, lower and upper case matters!
| <transform id="at" frequence="DAILY" resource="locations" class="net.simplace.sim.transformers.AstronomicParametersTransformer">
| <header>
| <res id="DOY" datatype="INT" key="CURRENT.DOY" />
| <res id="LocationId" datatype="CHAR" key="vActualLocation" />
| <res id="DayLength" datatype="DOUBLE" />
| <res id="PhotoperiodicDayLength" datatype="DOUBLE" />
| <res id="SolarConstant" datatype="DOUBLE" />
| <res id="SINLD" datatype="DOUBLE" />
| <res id="COSLD" datatype="DOUBLE" />
| <res id="DSINB" datatype="DOUBLE" />
| <res id="DSINBE" datatype="DOUBLE" />
| </header>
| <input id="SunInclinationField">SunInclination</input>
| <input id="LatitudeField">Latitude</input>
| <input id="IdField">LocationId</input>
| </transform>
The calculation method follows mainly the routine from the Gecros model (1),
see also (2) and (3):
Differences between this routine and Gecros
- Gecros limits the latitude between -67 and 67 degrees. This routine extends the range from -90 to 90 degrees as in Lintul5 (2)
- Sine and Cosine of declination are calculated directly (in a mathematical equivalent way)
- Values are calculated with double precision, which might result in slightly different values than from the FORTRAN code.
Conversion factor from degrees to radians. The original Fortran/FST-Modules use a less
precise approximation of \(\pi \approx 3.141592654\), whereas here \(\pi \approx 3.141592653589793\).
\[
\begin{eqnarray}
rad &=& \frac{\pi}{180}\\
\end{eqnarray}
\]
Sine and cosine of latitude, maximal declination. Values calculated only once per location.
\[
\begin{eqnarray}
sinlat &=& \sin(rad \cdot latitutde)\\
coslat &=& \cos(rad \cdot latitutde)\\
sindcm &=& \sin(rad \cdot 23.45)\\
\end{eqnarray}
\]
Sine and cosine of declination of the sun as function of day of year.
Calculation is taken from Goudriaan, van Laar 1994.
Some models first calculate \(dec\) as the arcsine of \(sindec\) and
then take the sine and cosine. The methods are mathematically equivalent
due to \(sin^2+cos^2=1\)
\[
\begin{eqnarray}
sindec &=& -sindcm \cos(2 \pi \frac{doy+10}{365})\\
cosdec &=& \sqrt{1-sindec^2}\\
sinld &=& sinlat \cdot sindec\\
cosld &=& coslat \cdot cosdec
\end{eqnarray}
\]
Daylength calculation.
\[
\begin{eqnarray}
arg &=& \min(1,\max(-1,\frac{sinld}{cosld}))\\
daylength &=& 12 (1 + \frac{2}{\pi} \arcsin(arg))\\
\end{eqnarray}
\]
Photoperiodic daylength
\[
\begin{eqnarray}
arg2 &=& \min(1,\max(-1,\frac{-\sin(rad \cdot inclination)+sinld}{cosld}))\\
ddlp &=& 12(1+\frac{2}{\pi}\arcsin(arg2))\\
\end{eqnarray}
\]
Solar constant
\[
\begin{eqnarray}
sc &=& 1367(1 + 0.033 \cos(2 \pi\frac{doy-10}{365}))\\
\end{eqnarray}
\]
Daily total of effective solar height
\[
\begin{eqnarray}
dsinb &=& 3600(dayl \cdot sinld+24 cosld \frac{\sqrt{1-arg^2}}{\pi})\\
dsinbe &=& 3600(dayl(sinld+0.4(sinld^2+\frac{cosld^2}{2})) + 12 cosld(2+3\cdot 0.4 sinld)\frac{\sqrt{1-arg^2}}{\pi})
\end{eqnarray}
\]
Notice: The sine of solar height is \(sin\beta(h) = sinld + cosld \cdot \cos(2 \pi \frac{h-12}{24})\), \(dsinb\) is the integral \(\int_0^{24} sin\beta(h)dh\) converted to seconds.
Utilisation
Transformer is used in the FST based models:
Notice
Transformer works only with resources that have a single column key (that identifies the location)
The transformed resource has two keys: the DOY and the key from the resource.
Tweaks
Instead of transforming a resource, the transformer can get the values for latitude and inclination
directly and generate day lengths etc.
In order to use the transformer this way, you have to omit the resource attribute.
LatitudeField and SunInclinationField should then reference the coresponding DOUBLE variables.
| <var id="vActualLocation" datatype="CHAR">sevilla</var>
| <var id="vLatitude" datatype="DOUBLE">53.1</var>
| <var id="vSunInclination" datatype="DOUBLE">-2.5</var>
| ...
| <transform id="at" frequence="DAILY" resource="locations" class="net.simplace.sim.transformers.AstronomicParametersTransformer">
| <header>
| <res id="DOY" datatype="INT" key="CURRENT.DOY" />
| <res id="LocationId" datatype="CHAR" key="vActualLocation" />
| <res id="DayLength" datatype="DOUBLE" />
| ...
| </header>
| <input id="SunInclinationField">vSunInclination</input>
| <input id="LatitudeField">vLatitude</input>
| <input id="IdField">vActualLocation</input>
| </transform>
It's recommended to use the transformer with a resource, rather than the tweaked method.
You can't mix the two methods by taking one value from the resource and another directly.
The way of configuring the tweaked method might change (especially the ids of the inputs
might be renamed to distinguish them from the inputs of the standart method).
References
- (1) YIN, X. and van Laar, H. H., Crop Systems Dynamics, 2005
- (2) Wolf, J., User guide for Lintul 5, 2012 http://models.pps.wur.nl/sites/models.pps.wur.nl/files/LINTUL5-report-vs1_0.zip
- (3) Goudriaan, Modeling Potential Crop Growth Processes, 1994, (revised version Nov. 2004)
public class AstronomicParametersTransformer extends
net.simplace.sim.io.resources.FWSimResourceTransformer {
// Public Constructors
public AstronomicParametersTransformer(FWSimSession aSession, Element
aResourceElement, Integer aOrderNumber);
public AstronomicParametersTransformer(FWSimSession aSession, Integer
aOrderNumber);
// Public Instance Methods public HashMap createVariables(); // Defines
net.simplace.sim.io.FWSimIOAdapter
public FWSimResourceCache getData(FWSimVarMap aVarMap)
throws MissingSimResourceException; // Defines
net.simplace.sim.io.resources.FWSimInputAdapter
standard method from outside
public FWSimResourceCache
getData(FWSimVarMap aVarMap, FWSimResourceCache
aResourceCache) throws MissingSimResourceException;
used by test cases
- aVarMap
variable map
- aResourceCache
Cached resources (soil data)
returns delivered new data from transformer
public FWSimResourceCache
calculateDaylength(FWSimVariable aIdname,
FWSimVariable aLatitudename, FWSimVariable aInclinationname,
FWSimResourceCache aCache, FWSimVarMap aVarMap)
throws MissingSimResourceException;
Calculates Daylengths
- aIdname
- aLatitudename
- aInclinationname
- idname
- latitudename
- inclinationname
- aCache
original soil info stored
- aVarMap
returns the new created {@link FWSimResourceCache}
public void updateFields(FWObservable aObservable);
// Defines net.simplace.sim.io.resources.FWSimResourceTransformer
}
Hierarchy: java.lang.Object - net.simplace.sim.io.FWSimIOAdapter (net.simplace.sim.util.FWSimFieldContainer) - net.simplace.sim.io.resources.FWSimInputAdapter - net.simplace.sim.io.resources.FWSimResourceTransformer - AstronomicParametersTransformer