Index: trunk/MagicSoft/Mars/Changelog
===================================================================
--- trunk/MagicSoft/Mars/Changelog	(revision 9350)
+++ trunk/MagicSoft/Mars/Changelog	(revision 9351)
@@ -53,4 +53,18 @@
    * mimage/MHHillas.cc, mimage/MMHillas.Ext.cc, mimage/MHHillasSrc.cc:
      - converted default binning from mm to deg
+
+   * mraw/MRawRunHeader.cc:
+     - print less when values doen't have any meaning
+
+   * msim/MSimAtmosphere.[h,cc]:
+     - added
+
+   * msim/SimLinkDef.h, msim/Makefile:
+     - added MSimAtmosphere
+
+   * mjobs/MJSimulation.cc:
+     - added simulation of atmosphere
+     - clean isolated pixels away before calculating image parameters
+     - don't clean calibration runs
 
 
Index: trunk/MagicSoft/Mars/NEWS
===================================================================
--- trunk/MagicSoft/Mars/NEWS	(revision 9350)
+++ trunk/MagicSoft/Mars/NEWS	(revision 9351)
@@ -75,5 +75,13 @@
      memory and it was never freed, so the program took this memory
      until the end)
- 
+
+   * Converted the code from MMCS' reflector program to MSimAtmosphere
+     (instead of the tables build in for MAGIC Winter and Summer 
+     atmosphere we use the values written by Corsika fitted to the
+     tabulated atmosphere given as input)
+
+   * For caluclating the displayed image parameters in ceres a basic
+     image cleaning removing isolated pixels is now done.
+
  ;star
 
Index: trunk/MagicSoft/Mars/mjobs/MJSimulation.cc
===================================================================
--- trunk/MagicSoft/Mars/mjobs/MJSimulation.cc	(revision 9350)
+++ trunk/MagicSoft/Mars/mjobs/MJSimulation.cc	(revision 9351)
@@ -80,4 +80,5 @@
 #include "MSimMMCS.h"
 #include "MSimAbsorption.h"
+#include "MSimAtmosphere.h"
 #include "MSimReflector.h"
 #include "MSimPointingPos.h"
@@ -326,4 +327,5 @@
     MSimMMCS simmmcs;
 
+    MSimAtmosphere simatm;
     MSimAbsorption absapd("PhotonDetectionEfficiency");
     MSimAbsorption absmir("MirrorReflectivity");
@@ -511,6 +513,8 @@
     // -------------------------------------------------------------------
 
-    // FIXME: Remove isolated pixels
-    MImgCleanStd clean(7, 4.5);
+    // Remove isolated pixels
+    MImgCleanStd clean(0, 0);
+    clean.SetCleanLvl0(0); // The level above which isolated pixels are kept
+    clean.SetCleanRings(0);
     clean.SetMethod(MImgCleanStd::kAbsolute);
 
@@ -551,5 +555,6 @@
         //    if (header.IsPointRun())
         //        tasks.AddToList(&stars);
-        //tasks.AddToList(&print);
+        if (1)
+            tasks.AddToList(&simatm); // Here because before fillh1
         tasks.AddToList(&fillh1);
         tasks.AddToList(&fillG);
@@ -558,4 +563,6 @@
             tasks.AddToList(&absapd);
             tasks.AddToList(&absmir);
+            if (0)
+                tasks.AddToList(&simatm); // FASTER?
         }
         tasks.AddToList(&reflect);
@@ -628,5 +635,6 @@
         tasks.AddToList(&fillx0a);
         tasks.AddToList(&fillx0c);
-        //tasks.AddToList(&clean);
+        if (!header.IsCalibrationRun())
+            tasks.AddToList(&clean);
         tasks.AddToList(&hcalc);
         tasks.AddToList(&fillx0d);
Index: trunk/MagicSoft/Mars/mraw/MRawRunHeader.cc
===================================================================
--- trunk/MagicSoft/Mars/mraw/MRawRunHeader.cc	(revision 9350)
+++ trunk/MagicSoft/Mars/mraw/MRawRunHeader.cc	(revision 9351)
@@ -957,6 +957,9 @@
     if (fFormatVersion>5)
         *fLog << "Observation: '" << fObservationMode << "'" << endl;
-    *fLog << "Source:      '" << fSourceName << "' " << "  ";
-    *fLog << fSourceEpochChar << dec << fSourceEpochDate << endl;
+    if (fSourceName[0]!=0 || fSourceEpochChar[0]!=0 || fSourceEpochDate!=0)
+    {
+        *fLog << "Source:      '" << fSourceName << "' " << "  ";
+        *fLog << fSourceEpochChar << dec << fSourceEpochDate << endl;
+    }
     if (fRunStart)
         *fLog << "Run Start:    " << fRunStart << endl;
@@ -974,8 +977,11 @@
     else
         *fLog << (fNumSamplesLoGain+fNumSamplesHiGain) * fNumBytesPerSample << "B/pix" << endl;
-    *fLog << "Evt Counter:  " << fNumEvents;
-    if (fFormatVersion>8)
-        *fLog << " (read=" << fNumEventsRead << ")";
-    *fLog << endl;
+    if (fNumEvents>0 || fNumEventsRead>0)
+    {
+        *fLog << "Evt Counter:  " << fNumEvents;
+        if (fFormatVersion>8)
+            *fLog << " (read=" << fNumEventsRead << ")";
+        *fLog << endl;
+    }
 
     if (TString(t).Contains("header", TString::kIgnoreCase))
Index: trunk/MagicSoft/Mars/msim/MSimAtmosphere.cc
===================================================================
--- trunk/MagicSoft/Mars/msim/MSimAtmosphere.cc	(revision 9351)
+++ trunk/MagicSoft/Mars/msim/MSimAtmosphere.cc	(revision 9351)
@@ -0,0 +1,869 @@
+/* ======================================================================== *\
+!
+! *
+! * This file is part of CheObs, the Modular Analysis and Reconstruction
+! * Software. It is distributed to you in the hope that it can be a useful
+! * and timesaving tool in analysing Data of imaging Cerenkov telescopes.
+! * It is distributed WITHOUT ANY WARRANTY.
+! *
+! * Permission to use, copy, modify and distribute this software and its
+! * documentation for any purpose is hereby granted without fee,
+! * provided that the above copyright notice appears in all copies and
+! * that both that copyright notice and this permission notice appear
+! * in supporting documentation. It is provided "as is" without express
+! * or implied warranty.
+! *
+!
+!
+!   Author(s): Thomas Bretz,  1/2009 <mailto:tbretz@astro.uni-wuerzburg.de>
+!
+!   Copyright: CheObs Software Development, 2000-2009
+!
+!
+\* ======================================================================== */
+
+//////////////////////////////////////////////////////////////////////////////
+//
+//  MSimAtmosphere
+//
+//  Task to calculate wavelength or incident angle dependent absorption
+//
+//  Input Containers:
+//   MPhotonEvent
+//   MCorsikaRunHeader
+//
+//  Output Containers:
+//   MPhotonEvent
+//
+//////////////////////////////////////////////////////////////////////////////
+#include "MSimAtmosphere.h"
+
+#include <fstream>
+
+#include <TGraph.h>
+#include <TRandom.h>
+
+#include "MLog.h"
+#include "MLogManip.h"
+
+#include "MParList.h"
+
+#include "MCorsikaRunHeader.h"
+#include "MPhotonEvent.h"
+#include "MPhotonData.h"
+
+ClassImp(MSimAtmosphere);
+
+using namespace std;
+
+// ==========================================================================
+//
+// January 2002, A. Moralejo: We now precalculate the slant paths for the
+// aerosol and Ozone vertical profiles, and then do an interpolation in
+// wavelength for every photon to get the optical depths. The parameters
+// used, defined below, have been taken from "Atmospheric Optics", by
+// L. Elterman and R.B. Toolin, chapter 7 of the "Handbook of geophysics
+// and Space environments". (S.L. Valley, editor). McGraw-Hill, NY 1965.
+// 
+// WARNING: the Mie scattering and the Ozone absorption are implemented
+// to work only with photons produced at a height a.s.l larger than the
+// observation level. So this is not expected to work well for simulating
+// the telescope pointing at theta > 90 deg (for instance for neutrino
+// studies. Rayleigh scattering works even for light coming from below.
+// 
+// Fixed bugs (of small influence) in Mie absorption implementation: there
+// were errors in the optical depths table, as well as a confusion:
+// height a.s.l. was used as if it was height above the telescope level.
+// The latter error was also present in the Ozone aborption implementation.
+// 
+// On the other hand, now we have the tables AE_ABI and OZ_ABI with optical
+// depths between sea level and a height h (before it was between 2km a.s.l
+// and a height h). So that we can simulate also in the future a different
+// observation level.
+// 
+// AM: WARNING: IF VERY LARGE zenith angle simulations are to be done (say
+// above 85 degrees, for neutrino primaries or any other purpose) this code
+// will have to be adapted accordingly and checked, since in principle it has
+// been written and tested to simulate the absorption of Cherenkov photons
+// arriving at the telescope from above.
+// 
+// AM: WARNING 2: not to be used for wavelengths outside the range 250-700 nm
+// 
+// January 2003, Abelardo Moralejo: found error in Ozone absorption treatment.
+// At large zenith angles, the air mass used was the one calculated for
+// Rayleigh scattering, but since the Ozone distribution is rather different
+// from the global distribution of air molecules, this is not a good
+// approximation. Now I have left in this code only the Rayleigh scattering,
+// and moved to atm.c the Mie scattering and Ozone absorption calculated in
+// a better way.
+// 
+// A. Moralejo, January 2003: added some parameters for Mie scattering
+// and Ozone absorption derived from the clear standard atmosphere model
+// in "Atmospheric Optics", by L. Elterman and R.B. Toolin, chapter 7 of
+// the "Handbook of geophysics and Space environments". S.L. Valley,
+// editor. McGraw-Hill, NY 1965.
+// 
+// AM, Jan 2003: Changed the meaning of the argument height: now it is the
+// true height above sea level at which a photon has been emitted, before
+// it was the height given by Corsika, measured in the vertical of the
+// observer and not in the vertical of the emitting particle.
+//
+//
+// MAGIC-Winter and MAGIC-Summer by M. Haffke,
+// parametrizing profiles obtained with MSIS:
+// http://uap-www.nrl.navy.mil/models_web/msis/msis_home.htm
+//
+//
+// The MAGIC-Winter and MAGIC-Summer parametrisations reproduce the MSIS
+// profiles for the 3 atmospheric layers from 0 up to 40 km height. Beyond
+// that height, it was not possible to achieve a good fit, but the amount
+// of residual atmosphere is so small that light absorption would be
+// negligible anyway. Showers develop well below 40 km.
+//
+//
+// The mass overburden is given by T = AATM + BATM * exp(-h/CATM)
+// The last layer of the US standard atmosphere (in which T varies
+// linearly with h) is above 100 km and has not been included here
+// because it should not matter.
+//
+class MAtmRayleigh
+{
+private:
+    static const Double_t fgMeanFreePath; // [g/cm^2] Mean free path for scattering Rayleigh XR
+
+    Double_t fR;         // [cm] Earth radius to be used
+
+    Double_t fHeight[5]; // Layer boundaries (atmospheric layer)
+
+    // Parameters of the different atmospheres. We use the same parametrization
+    // shape as in Corsika atmospheric models (see Corsika manual, appendix D).
+    // The values here can be/are obtained from the Corsika output
+    //Float_t  fAtmA[4];   // The index refers to the atmospheric layer (starting from sea level and going upwards)
+    Float_t  fAtmB[4];   // The index refers to the atmospheric layer (starting from sea level and going upwards)
+    Float_t  fAtmC[4];   // The index refers to the atmospheric layer (starting from sea level and going upwards)
+
+    Double_t fRho[5];    // Precalculated integrals for rayleigh scatterning
+
+    // --------------------------------------------------------------------------
+    //
+    // Precalcalculate the integrals from the observer level to the next
+    // atmpsheric layer below including the lower boundary. Thus a
+    // correct calculation is reduced to the calculation of the upper
+    // boundary.
+    //
+    // fRho[0] = B0;
+    // fRho[1] = B0-A0 + B1;
+    // fRho[2] = B0-A0 + B1-A1 + B2;
+    // fRho[3] = B0-A0 + B1-A1 + B2+A2 + B3;
+    // fRho[4] = B0-A0 + B1-A1 + B2+A2 + B3 - A3;
+    //
+    void PreCalcRho()
+    {
+        // Limits (height in cm) of the four layers in which
+        // atmosphere is parametrized.
+        // This is a stupid trick giving 0 for the integrals below
+        // the observer
+
+        const Double_t h[5] =
+        {
+            fObsLevel,                       //   0km
+            TMath::Max(fObsLevel, 4e5),      //   4km
+            1.0e6,                           //  10km
+            4.0e6,                           //  40km
+            1.0e7                            // 100km
+        };
+
+        memcpy(fHeight, h, sizeof(Double_t)*5);
+
+        fRho[0] = 0;
+        for (int i=0; i<4; i++)
+        {
+            const Double_t b = fAtmB[i];
+            const Double_t c = fAtmC[i];
+
+            const Double_t h1 = h[i+1];
+            const Double_t h0 = h[i];
+
+            const Double_t B = b*TMath::Exp(-h0/c);
+            const Double_t A = b*TMath::Exp(-h1/c);
+
+            // Calculate rho for the i-th layer from the lower
+            // to the higher layer boundary.
+            // If height is within the layer only calculate up to height.
+            fRho[i]  += B;
+            fRho[i+1] = fRho[i] - A;
+        }
+    }
+
+protected:
+    Double_t fObsLevel; // [cm] observation level a.s.l.
+
+public:
+    // Init an atmosphere from the data stored in MCorsikaRunHeader
+    MAtmRayleigh(const MCorsikaRunHeader &h)
+    {
+        Init(h);
+    }
+
+    // Defualt constructor
+    MAtmRayleigh() : fObsLevel(-1) { }
+
+    // Check if the ovservation level has been correctly initialized
+    // Used as a marker for correct initialization
+    Bool_t IsValid() const { return fObsLevel>=0; }
+
+    // Get the Earth radius to be used
+    Double_t R() const { return fR; }
+
+    // Init an atmosphere from the data stored in MCorsikaRunHeader
+    // This initialized fObsLevel, fR, fAtmB and fAtmC and
+    // PreCalcRho
+    void Init(const MCorsikaRunHeader &h)
+    {
+        // Observation level above earth radius
+        fObsLevel = h.GetObsLevel();
+
+        // Use earth radius as defined in Corsika
+        fR = h.EarthRadius();
+
+        //memcpy(fAtmA, (Float_t*)h.GetAtmosphericCoeffA(), sizeof(Float_t)*4);
+        memcpy(fAtmB, (Float_t*)h.GetAtmosphericCoeffB(), sizeof(Float_t)*4);
+        memcpy(fAtmC, (Float_t*)h.GetAtmosphericCoeffC(), sizeof(Float_t)*4);
+
+        PreCalcRho();
+    }
+
+    // Return the vertical thickness between the observer and height.
+    // Therefor the integral of the layers below (including the lower
+    // boudary) Have been precalculated by PreCalcRho
+    Double_t GetVerticalThickness(Double_t height) const
+    {
+        // FIXME: We could store the start point above obs-level
+        //        (Does this really gain anything?)
+        Int_t i=0;
+        while (i<4 && height>fHeight[i+1])
+            i++;
+
+        const Double_t b = fAtmB[i];
+        const Double_t c = fAtmC[i];
+
+        return fRho[i] - b*TMath::Exp(-height/c);
+    }
+
+    /*
+     // The "orginal" code for the vertical thickness
+    Double_t GetVerticalThickness(Double_t obslev, Double_t height) const
+    {
+        // This is a C++-version of the original code from attenu.c
+
+        // Limits (height in cm) of the four layers in which atmosphere is parametrized:
+        const double lahg[5] =
+        {
+            obslev,
+            TMath::Max(obslev, 4e5),
+            1.0e6,
+            4.0e6,
+            1.0e7
+        };
+
+        Double_t Rho_Tot = 0.0;
+        for (int i=0; i<4; i++)
+        {
+            const Double_t b = fAtmB[i];
+            const Double_t c = fAtmC[i];
+
+            const Double_t h0 = TMath::Min(height, lahg[i+1]);
+            const Double_t h1 =                    lahg[i];
+
+            // Calculate rho for the i-th layer from the lower
+            // to the higher layer boundary.
+            // If height is within the layer only calculate up to height.
+            Rho_Tot += b*(exp(-h1/c) - exp(-h0/c));
+
+            if (lahg[i+1] > height)
+                break;
+        }
+
+        return Rho_Tot;
+    }
+    */
+    Double_t CalcTransmission(Double_t height, Double_t wavelength, Double_t sin2) const
+    {
+        // sin2: sin(theta)^2
+        // height is the true height a.s.l.
+
+        // LARGE ZENITH ANGLE FACTOR (AIR MASS FACTOR):
+        // Air mass factor "airmass" calculated using a one-exponential
+        // density profile for the atmosphere,
+        //
+        //     rho = rho_0 exp(-height/hscale) with hscale = 7.4 km
+        //
+        // The air mass factor is defined as I(theta)/I(0), the ratio of
+        // the optical paths I (in g/cm2) traversed between two given
+        // heights, at theta and at 0 deg z.a.
+
+        const Double_t H = height-fObsLevel;
+        const Double_t h = 2*H;
+
+        // Scale-height (cm) for Exponential density profile
+        const Double_t hscale = 7.4e5;
+        const Double_t f      = 2*hscale;
+
+        // Precalc R*cos(theta)^2 (FIXME: Is ph.GetCosW2 more precise?)
+        const Double_t Rcos2 = fR * (1-sin2); // cos2 = 1 - sin2
+
+        const Double_t x1 = TMath::Sqrt((Rcos2      ) / f);
+        const Double_t x2 = TMath::Sqrt((Rcos2 + 2*h) / f);
+        const Double_t x3 = TMath::Sqrt((fR         ) / f);
+        const Double_t x4 = TMath::Sqrt((fR    + 2*h) / f);
+
+        // Return a -1 transmittance in the case the photon comes
+        // exactly from the observation level, because in that case the
+        // "air mass factor" would become infinity and the calculation
+        // is not valid!
+        if (fabs(x3-x4) < 1.e-10)
+            return  -1.;
+
+        const Double_t e12 = erfc(x1) - erfc(x2);
+        const Double_t e34 = erfc(x3) - erfc(x4);
+
+        const Double_t airmass = TMath::Exp(-fR*sin2 / f) * e12/e34;
+
+        // Calculate the traversed "vertical thickness" of air using the
+        // US Standard atmosphere:
+        const Double_t Rho_tot = GetVerticalThickness(/*fObsLevel,*/ height);
+
+        // We now convert from "vertical thickness" to "slanted thickness"
+        // traversed by the photon on its way to the telescope, simply
+        // multiplying by the air mass factor m:
+        const Double_t Rho_Fi = airmass * Rho_tot;
+
+        // Finally we calculate the transmission coefficient for the Rayleigh
+        // scattering:
+        // AM Dec 2002, introduced ABS below to account (in the future) for
+        // possible photons coming from below the observation level.
+
+        const Double_t wl = 400./wavelength;
+
+        // Mean free path for scattering Rayleigh XR (g/cm^2)
+        return TMath::Exp(-TMath::Abs(Rho_Fi/fgMeanFreePath)*wl*wl*wl*wl);
+    }
+};
+
+// ==========================================================================
+
+class MAtmosphere : public MAtmRayleigh
+{
+private:
+    static const Double_t STEPTHETA; // aprox. 1 degree
+
+    // Aerosol number density for 31 heights a.s.l., from 0 to 30 km,
+    // in 1 km steps (units: cm^-3)
+    static const Double_t aero_n[31];
+
+    // Ozone concentration for 51 heights a.s.l., from 0 to 50 km,
+    // in 1 km steps (units: cm/km)
+    static const Double_t oz_conc[51];
+
+    // aerosol_path contains the path integrals for the aerosol number
+    // density (relative to the number density at sea level) between the
+    // observation level and a height h for different zenith angles. The
+    // first index indicate height above sea level in units of 100m, the
+    // second is the zenith angle in degrees.
+    float aerosol_path[301][90];
+
+    // ozone_path contains the path integrals for the ozone concentration
+    // between the observation level and a height h for different zenith
+    // angles. The first index indicate height above sea level in units
+    // of 100m, the second is the zenith angle in degrees.
+    float ozone_path[501][90];
+
+    // Interpolate the graph at wavelength
+    Double_t GetBeta(Double_t wavelength, const TGraph &g) const
+    {
+        // FIXME: This might not be the fastest because range
+        // checks are done for each call!
+        return g.GetN()==0 ? 0 : g.Eval(wavelength)*1e-5; // from km^-1 to cm^-1
+/*
+        // Linear interpolation
+        // (FIXME: Is it faster to be replaced with a binary search?)
+        // (       This might be faster because we have more photons
+        //         with smaller wavelengths)
+        //int index;
+        //for (index = 1; index <g.GetN()-1; index++)
+        //    if (wavelength < g.GetX()[index])
+        //        break;
+        const Int_t index = TMath::BinarySearch(g.GetN(), g.GetX(), wavelength)+1;
+
+        const Double_t t0 = g.GetY()[index-1];
+        const Double_t t1 = g.GetY()[index];
+
+        const Double_t w0 = g.GetX()[index-1];
+        const Double_t w1 = g.GetX()[index];
+
+        const Double_t beta0 = t0+(t1-t0)*(wavelength-w0)/(w1-w0);
+
+        return beta0 * 1e-5; // from km^-1 to cm^-1
+        */
+    }
+
+
+    //MSpline3 *fAbsCoeffOzone;
+    //MSpline3 *fAbsCoeffAerosols;
+
+    TGraph *fAbsCoeffOzone;
+    TGraph *fAbsCoeffAerosols;
+
+public:
+    MAtmosphere(const MCorsikaRunHeader &h) : fAbsCoeffOzone(0), fAbsCoeffAerosols(0)
+    {
+        Init(h, "ozone.txt", "aerosols.txt");
+    }
+
+    MAtmosphere(const char *name1="ozone.txt", const char *name2="aerosols.txt") : fAbsCoeffOzone(0), fAbsCoeffAerosols(0)
+    {
+        InitOzone(name1);
+        InitAerosols(name2);
+    }
+
+    ~MAtmosphere()
+    {
+        if (fAbsCoeffOzone)
+            delete fAbsCoeffOzone;
+        if (fAbsCoeffAerosols)
+            delete fAbsCoeffAerosols;
+    }
+
+    Float_t GetWavelengthMin() const { return fAbsCoeffOzone && fAbsCoeffAerosols ? TMath::Max(fAbsCoeffOzone->GetX()[0], fAbsCoeffAerosols->GetX()[0]) : -1; }
+    Float_t GetWavelengthMax() const { return fAbsCoeffOzone && fAbsCoeffAerosols ? TMath::Min(fAbsCoeffOzone->GetX()[fAbsCoeffOzone->GetN()-1], fAbsCoeffAerosols->GetX()[fAbsCoeffAerosols->GetN()-1]) : -1; }
+
+    Bool_t HasValidOzone() const   { return fAbsCoeffOzone    && fAbsCoeffOzone->GetN()>0; }
+    Bool_t HasValidAerosol() const { return fAbsCoeffAerosols && fAbsCoeffAerosols->GetN()>0; }
+
+    Bool_t IsAllValid() const { return IsValid() && HasValidOzone() && HasValidAerosol(); }
+
+    void PreCalcOzone()
+    {
+        // It follows a precalculation of the slant path integrals we need
+        // for the estimate of the Mie scattering and Ozone absorption:
+        Double_t dh = 1.e3;
+        const Double_t STEPTHETA = 1.74533e-2; // aprox. 1 degree
+
+        // Ozone absorption
+        for (Int_t j = 0; j < 90; j++)
+        {
+            const Double_t theta = j * STEPTHETA;  
+            const Double_t sin2  = sin(theta)*sin(theta);
+            const Double_t H     = R()+fObsLevel;
+
+            Double_t path_slant = 0;
+            for (Double_t h = fObsLevel; h <= 50e5; h += dh)
+            {
+                // h is the true height vertical above ground
+                if (fmod(h,1e4) == 0)
+                    ozone_path[(int)(h/1e4)][j] = path_slant;
+
+                const Double_t km  = h/1e5;
+                const Int_t    i   = TMath::FloorNint(km);
+                const Double_t l   = R()+h;
+
+                const Double_t L   = TMath::Sqrt(l*l - H*H * sin2);
+                const Double_t f   = dh * l / L;
+
+                // Linear interpolation at h/1e5
+                Double_t interpol = oz_conc[i] + fmod(km, 1) * (oz_conc[i+1]-oz_conc[i]);
+
+                path_slant += f * interpol;
+            }
+        }
+    }
+
+    void PreCalcAerosol()
+    {
+        // It follows a precalculation of the slant path integrals we need
+        // for the estimate of the Mie scattering and Ozone absorption:
+        Double_t dh = 1.e3;
+        const Double_t STEPTHETA = 1.74533e-2; // aprox. 1 degree
+
+        /* Mie (aerosol): */
+        for (Int_t j = 0; j < 90; j++)
+        {
+            const Double_t theta = j * STEPTHETA;  
+            const Double_t sin2  = sin(theta)*sin(theta);
+            const Double_t H     = R()+fObsLevel;
+
+            Double_t path_slant = 0;
+            for (Double_t h = fObsLevel; h <= 30e5; h += dh)
+            {
+                // h is the true height vertical above ground
+                if (fmod(h,1e4) == 0)
+                    aerosol_path[(int)(h/1e4)][j] = path_slant;
+
+                const Double_t km  = h/1e5;
+                const Int_t    i   = TMath::FloorNint(km);
+                const Double_t l   = R()+h;
+
+                const Double_t L   = TMath::Sqrt(l*l - H*H * sin2);
+                const Double_t f   = dh * l / L;
+
+                // Linear interpolation at h/1e5
+                Double_t interpol = aero_n[i] + fmod(km, 1)*(aero_n[i+1]-aero_n[i]);
+
+                path_slant += f * interpol/aero_n[0];    // aero_n [km^-1]
+            }
+        }
+    }
+
+    Bool_t InitOzone(const TString name="")
+    {
+        if (!name.IsNull())
+        {
+            if (fAbsCoeffOzone)
+                delete fAbsCoeffOzone;
+
+            fAbsCoeffOzone = new TGraph(name);
+            fAbsCoeffOzone->Sort();
+        }
+
+        if (!HasValidAerosol())
+            return kFALSE;
+
+        if (IsValid())
+            PreCalcOzone();
+
+        return kTRUE;
+    }
+
+    Bool_t InitAerosols(const TString name="")
+    {
+        if (!name.IsNull())
+        {
+            if (fAbsCoeffAerosols)
+                delete fAbsCoeffAerosols;
+
+            fAbsCoeffAerosols = new TGraph(name);
+            fAbsCoeffAerosols->Sort();
+        }
+
+        if (!HasValidAerosol())
+            return kFALSE;
+
+        if (IsValid())
+            PreCalcOzone();
+
+        return kTRUE;
+    }
+
+    void Init(const MCorsikaRunHeader &h, const char *name1=0, const char *name2=0)
+    {
+        MAtmRayleigh::Init(h);
+
+        InitOzone(name1);
+        InitAerosols(name2);
+    }
+/*
+    Double_t GetOz(Double_t height, Double_t theta) const
+    {
+        // Distance between two points D = 1km /cos(theta)
+        // Density along y within this km:   f =  (x[i+1]-x[i])/1km * dy
+        // Integral of this density  f =  (x[i+1]-x[i])/1km * (y[i+1]-y[i])
+        // f(h) = int [ (c1-c0)/1km*(h-h0)*dh + c0 ] dh
+        //      = (c-co)*(h-h0)
+
+        Double_t rc = 0;
+        int i;
+        for (i=0; i<49; i++)
+            if (i>=2 && i+1<height/1e5)    // cm -> km
+                rc += oz_conc[i] * 1e5/cos(theta);
+
+        rc -= oz_conc[2]*0.2*1e5/cos(theta);
+        rc += oz_conc[i+1]*fmod(height/1e5,1)*1e5/cos(theta);
+
+        return rc;
+    }
+    */
+
+    Double_t CalcOzoneAbsorption(Double_t h, Double_t wavelength, Double_t theta) const
+    {
+        if (!fAbsCoeffOzone)
+            return 1;
+
+        //******* Ozone absorption *******
+        if (h > 50.e5)
+            h = 50.e5;
+
+        // Vigroux Ozone absorption coefficient a.s.l. through interpolation:
+        //const float oz_vigroux[15]= {1.06e2, 1.01e1, 8.98e-1, 6.40e-2, 1.80e-3, 0, 0, 3.50e-3, 3.45e-2, 9.20e-2, 1.32e-1, 6.20e-2, 2.30e-2, 1.00e-2, 0.00};
+        //const Double_t beta0 = getbeta(wavelength, oz_vigroux);
+        const Double_t beta0 = GetBeta(wavelength, *fAbsCoeffOzone);
+
+        // Now use the pre-calculated values of the path integral
+        // for h and theta
+        const UInt_t H = TMath::Nint(h/1e4);
+        const UInt_t T = TMath::Min(89, TMath::Nint(theta/STEPTHETA));
+
+        const Double_t path = ozone_path[H][T];
+
+        return TMath::Exp(-beta0*path);
+    }
+
+    Double_t CalcAerosolAbsorption(Double_t h, Double_t wavelength, Double_t theta) const
+    {
+        if (!fAbsCoeffAerosols)
+            return 1;
+
+        //******* Mie (aerosol) *******
+        if (h > 30.e5)
+            h = 30.e5;
+
+        // Mie absorption coefficient at sea level through interpolation
+        //const float aero_betap[15] = {0.27, 0.26, 0.25, 0.24, 0.24, 0.23, 0.20, 0.180, 0.167, 0.158, 0.150, 0.142, 0.135, 0.127, 0.120};
+        //const Double_t beta0 = getbeta(wavelength, aero_betap);
+        const Double_t beta0 = GetBeta(wavelength, *fAbsCoeffAerosols);
+
+        // Now use the pre-calculated values of the path integral
+        // for h and theta
+        const UInt_t H = TMath::Nint(h/1e4);
+        const UInt_t T = TMath::Min(89, TMath::Nint(theta/STEPTHETA));
+
+        const Double_t path = aerosol_path[H][T];
+
+        return TMath::Exp(-beta0*path);
+    }
+
+    Double_t GetTransmission(const MPhotonData &ph) const
+    {
+        const Double_t wavelength = ph.GetWavelength();
+        const Double_t height     = ph.GetProductionHeight();
+
+        // Reduce the necessary number of floating point operations
+        // by storing the intermediate results
+        const Double_t sin2  = ph.GetSinW2();
+        const Double_t cost  = TMath::Sqrt(1-sin2);
+        const Double_t theta = TMath::ACos(cost);
+
+        // Path from production height to obslevel
+        const Double_t z = height-fObsLevel;
+
+        // Distance of emission point to incident point on ground
+        const Double_t d = z/cost;
+
+        // Avoid problems if photon is very close to telescope:
+        if (TMath::Abs(d)<1)
+            return 1;
+
+        // Earth radius plus observation height (distance of telescope
+        // from earth center)
+        const Double_t H = R() + fObsLevel;
+
+        // We calculate h, the true height a.s.l.
+        // of the photon emission point in cm
+        const Double_t h = TMath::Sqrt(H*H + d*d + 2*H*z) - R();
+
+        //**** Rayleigh scattering: *****
+        const Double_t T_Ray = CalcTransmission(h, wavelength, sin2);
+        if (T_Ray<0)
+            return 0;
+
+        //****** Ozone absorption: ******
+        const Double_t T_Oz  = CalcOzoneAbsorption(h, wavelength, theta);
+
+        //******** Mie (aerosol) ********
+        const Double_t T_Mie = CalcAerosolAbsorption(h, wavelength, theta);
+
+        // FIXME: What if I wanna display these values?
+
+        // Calculate final transmission coefficient
+        return T_Ray * T_Oz * T_Mie;
+    }
+};
+
+const Double_t MAtmosphere::STEPTHETA = 1.74533e-2; // aprox. 1 degree
+
+const Double_t MAtmRayleigh::fgMeanFreePath = 2970;
+
+const Double_t MAtmosphere::aero_n[31] = {200, 87, 38, 16, 7.2, 3.1, 1.1, 0.4, 0.14, 5.0e-2, 2.6e-2, 2.3e-2, 2.1e-2, 2.3e-2, 2.5e-2, 4.1e-2, 6.7e-2, 7.3e-2, 8.0e-2, 9.0e-2, 8.6e-2, 8.2e-2, 8.0e-2, 7.6e-2, 5.2e-2, 3.6e-2, 2.5e-2, 2.4e-2, 2.2e-2, 2.0e-2, 1.9e-2};
+
+const Double_t MAtmosphere::oz_conc[51]={0.3556603E-02, 0.3264150E-02, 0.2933961E-02, 0.2499999E-02, 0.2264150E-02, 0.2207546E-02, 0.2160377E-02, 0.2226414E-02, 0.2283018E-02, 0.2811320E-02, 0.3499999E-02, 0.4603772E-02, 0.6207545E-02, 0.8452828E-02, 0.9528299E-02, 0.9905657E-02, 0.1028302E-01, 0.1113207E-01, 0.1216981E-01, 0.1424528E-01, 0.1641509E-01, 0.1839622E-01, 0.1971697E-01, 0.1981131E-01, 0.1933962E-01, 0.1801886E-01, 0.1632075E-01, 0.1405660E-01, 0.1226415E-01, 0.1066037E-01, 0.9028300E-02, 0.7933960E-02, 0.6830187E-02, 0.5820753E-02, 0.4830188E-02, 0.4311319E-02, 0.3613206E-02, 0.3018867E-02, 0.2528301E-02, 0.2169811E-02, 0.1858490E-02, 0.1518867E-02, 0.1188679E-02, 0.9301884E-03, 0.7443394E-03, 0.5764149E-03, 0.4462263E-03, 0.3528301E-03, 0.2792452E-03, 0.2226415E-03, 0.1858490E-03};
+
+// ==========================================================================
+
+// --------------------------------------------------------------------------
+//
+//  Default Constructor.
+//
+MSimAtmosphere::MSimAtmosphere(const char* name, const char *title)
+    : fEvt(0), fAtmosphere(0)
+{
+    fName  = name  ? name  : "MSimAtmosphere";
+    fTitle = title ? title : "Simulate the wavelength and height-dependant atmpsheric absorption";
+
+    fAtmosphere = new MAtmosphere;
+}
+
+// --------------------------------------------------------------------------
+//
+//  Calls Clear()
+//
+MSimAtmosphere::~MSimAtmosphere()
+{
+    delete fAtmosphere;
+}
+
+// --------------------------------------------------------------------------
+//
+// Search for the needed parameter containers. Read spline from file
+// calling ReadFile();
+//
+Int_t MSimAtmosphere::PreProcess(MParList *pList)
+{
+    fEvt = (MPhotonEvent*)pList->FindObject("MPhotonEvent");
+    if (!fEvt)
+    {
+        *fLog << err << "MPhotonEvent not found... aborting." << endl;
+        return kFALSE;
+    }
+
+
+    return kTRUE;
+}
+
+// --------------------------------------------------------------------------
+//
+Bool_t MSimAtmosphere::ReInit(MParList *pList)
+{
+    MCorsikaRunHeader *h = (MCorsikaRunHeader*)pList->FindObject("MCorsikaRunHeader");
+    if (!h)
+    {
+        *fLog << err << "MCorsikaRunHeader not found... aborting." << endl;
+        return kFALSE;
+    }
+
+    //if (fRunHeader->Has(MCorsikaRunHeader::kRefraction))
+    //    *fLog << inf << "Atmospheric refraction already applied in Corsika... skipping our own." << endl;
+
+    // FIXME: Check wavelength range
+
+    /*
+    if (h->GetWavelengthMin()<fSpline->GetXmin())
+        *fLog << warn << "WARNING - Lower bound of wavelength bandwidth exceeds lower bound of spline." << endl;
+
+    if (h->GetWavelengthMax()>fSpline->GetXmax())
+        *fLog << warn << "WARNING - Upper bound of wavelength bandwidth exceeds upper bound of spline." << endl;
+    */
+
+    fAtmosphere->Init(*h);
+
+    if (!fAtmosphere->IsAllValid())
+    {
+        *fLog << err << "ERROR - Something with the atmoshere's initialization went wrong!" << endl;
+        return kFALSE;
+    }
+
+    if (h->GetWavelengthMin()<fAtmosphere->GetWavelengthMin())
+        *fLog << warn << "WARNING - Lower bound of wavelength bandwidth exceeds valid range of atmosphere." << endl;
+
+    if (h->GetWavelengthMax()>fAtmosphere->GetWavelengthMax())
+        *fLog << warn << "WARNING - Lower bound of wavelength bandwidth exceeds  valid range of atmosphere." << endl;
+
+    if (!h->Has(MCorsikaRunHeader::kAtmext))
+        *fLog << warn << "WARNING - ATMEXT option not used for Corsika data." << endl;
+
+    if (!h->Has(MCorsikaRunHeader::kRefraction))
+        *fLog << warn << "WARNING - Refraction calculation disabled for Corsika data." << endl;
+
+    return kTRUE;
+}
+
+// --------------------------------------------------------------------------
+//
+Int_t MSimAtmosphere::Process()
+{
+    // Get the number of photons in the list
+    const Int_t num = fEvt->GetNumPhotons();
+
+    // FIMXE: Add checks for
+    //         * upgoing particles
+    //         * Can we take the full length until the camera into account?
+
+    // Counter for number of total and final events
+    Int_t cnt = 0;
+    for (Int_t i=0; i<num; i++)
+    {
+        // Get i-th photon from the list
+        const MPhotonData &ph = (*fEvt)[i];
+
+        // Get atmospheric transmission for this photon
+        const Double_t eff = fAtmosphere->GetTransmission(ph);
+
+        // Get a random value between 0 and 1 to determine whether the photon will survive
+        // gRandom->Rndm() = [0;1[
+        if (gRandom->Rndm()>=eff)
+            continue;
+
+        // Copy the surviving events bakc in the list
+        (*fEvt)[cnt++] = ph;
+    }
+
+    // Now we shrink the array to the number of new entries.
+    fEvt->Shrink(cnt);
+
+    return kTRUE;
+}
+
+/*
+ Int_t MSimWavelength::Process()
+ {
+    // Get the number of photons in the list
+    const Int_t num = fEvt->GetNumPhotons();
+
+    // FIMXE: Add checks for
+    //         * upgoing particles
+    //         * wavelength range
+    //         * check if corsika atmosphere is switched on
+    //         * Can we take the full length until the camera into account?
+
+    // Counter for number of total and final events
+    Int_t cnt = 0;
+    for (Int_t i=0; i<num; i++)
+    {
+        // Get i-th photon from the list
+        MPhotonData &ph = (*fEvt)[i];
+
+        const Double_t min = fRunHeader->GetWavelengthMin(); // WAVLGL
+        const Double_t max = fRunHeader->GetWavelengthMax(); // WAVLGU
+        const Double_t f   = (max-min)/max;
+
+        // WAVELENGTH = 1. / (1/min - RD(1)/(min*max/(max-min)))
+
+
+        ph.SetWavelength(TMath::Nint(min / (1. - gRandom->Rndm()*f)));
+    }
+
+    return kTRUE;
+ }
+ */
+
+// --------------------------------------------------------------------------
+//
+// FileName: reflectivity.txt
+// UseTheta: No
+//
+Int_t MSimAtmosphere::ReadEnv(const TEnv &env, TString prefix, Bool_t print)
+{
+    Bool_t rc = kFALSE;
+/*
+    if (IsEnvDefined(env, prefix, "FileName", print))
+    {
+        rc = kTRUE;
+        SetFileName(GetEnvValue(env, prefix, "FileName", fFileName));
+    }
+
+    if (IsEnvDefined(env, prefix, "UseTheta", print))
+    {
+        rc = kTRUE;
+        SetUseTheta(GetEnvValue(env, prefix, "UseTheta", fUseTheta));
+    }
+*/
+    return rc;
+}
Index: trunk/MagicSoft/Mars/msim/MSimAtmosphere.h
===================================================================
--- trunk/MagicSoft/Mars/msim/MSimAtmosphere.h	(revision 9351)
+++ trunk/MagicSoft/Mars/msim/MSimAtmosphere.h	(revision 9351)
@@ -0,0 +1,38 @@
+#ifndef MARS_MSimAtmosphere
+#define MARS_MSimAtmosphere
+
+#ifndef MARS_MTask
+#include "MTask.h"
+#endif
+
+class MParList;
+class MAtmosphere;
+class MPhotonEvent;
+
+class MSimAtmosphere : public MTask
+{
+private:
+    MPhotonEvent *fEvt;        //! Event stroing the photons
+
+    MAtmosphere  *fAtmosphere; //! Instance of class describing atmosphere
+
+    // MParContainer
+    Int_t ReadEnv(const TEnv &env, TString prefix, Bool_t print=kFALSE);
+
+    // MTask
+    Int_t  PreProcess(MParList *pList);
+    Bool_t ReInit(MParList *pList);
+    Int_t  Process();
+
+public:
+    MSimAtmosphere(const char *name=NULL, const char *title=NULL);
+    ~MSimAtmosphere();
+
+    // MSimAtmosphere
+
+    // TObject
+
+    ClassDef(MSimAtmosphere, 0) // Simulate the wavelength and height-dependant atmpsheric absorption
+};
+
+#endif
Index: trunk/MagicSoft/Mars/msim/Makefile
===================================================================
--- trunk/MagicSoft/Mars/msim/Makefile	(revision 9350)
+++ trunk/MagicSoft/Mars/msim/Makefile	(revision 9351)
@@ -26,4 +26,5 @@
 	   MHPhotonEvent.cc \
 	   MSimMMCS.cc \
+	   MSimAtmosphere.cc \
 	   MSimAbsorption.cc \
 	   MSimPointingPos.cc
Index: trunk/MagicSoft/Mars/msim/SimLinkDef.h
===================================================================
--- trunk/MagicSoft/Mars/msim/SimLinkDef.h	(revision 9350)
+++ trunk/MagicSoft/Mars/msim/SimLinkDef.h	(revision 9351)
@@ -14,4 +14,5 @@
 #pragma link C++ class MSimPointingPos+;
 #pragma link C++ class MSimAbsorption+;
+#pragma link C++ class MSimAtmosphere+;
 
 #pragma link C++ class MSimMMCS+;
