Subversion Repositories public iLand

#ifndef SolarRadiation_H

#define SolarRadiation_H

//---------------------------------------------------------------------------

class HemiGrid;

/** Handles sun and radiation calculations.

  This class contains functions to calculate daylength, and hemipherical radiation intensities

  based on latitude. */

class SolarRadiation

{

public:

        SolarRadiation():  mMinDay(-1), mMaxDay(367), mDiffusRadFraction(0.5) {}

        void Setup(double BreiteGrad);

        /** calculate radiation matrix.

          calculates for each sector of the "Grid" the yearly radiation intensites.

          Intensities are influenced by latitude, vegetation period and the fraction of diffuse radiation.

          @param Step_deg size of one cell in degree (e.g. 5 -> each pixel has a size of 5°x5°)

          @param Grid results are stored in that HemiGrid (no setup required)    */

        void calculateRadMatrix(const float Step_deg, HemiGrid &Grid);

        /// set fraction of diffuse radiation (1: only diffuse rad, 0: only direct rad)

        void setDiffusRadFraction(double fraction_of_diffus_rad) { mDiffusRadFraction = fraction_of_diffus_rad; }

        /// set latitude in degree

        void setLatidude(const double lat_degree) { Latitude = lat_degree * M_PI/180.; }

        void setVegetationPeriod(int day_start, int day_end) { mMinDay=day_start; mMaxDay=day_end; }

private:

        int  FTime; ///< time of day

        double DayLength[366]; ///< length of day (seconds)

        double RadExtraTerrestrisch[366]; ///< total radiation Extraterrestrisch kJ/m2 daysum

        double SolarConstant; ///< radiation constant in space

        double Latitude;    ///< Latitude in rad

        int mMinDay; ///< start of vegetation period (day)

        int mMaxDay; ///< end of vegetation period (day)

        double mDiffusRadFraction;

        void calcDay(int day);

        ///< calculate daylength and daily radiation values

};

#endif