Base class for implementing an earth model. More...

#include <EarthModelBase.h>

Inheritance diagram for OscProb::EarthModelBase:

Public Member Functions
virtual void	SetDetPos (double rad, double lat=0, double lon=0)=0

virtual int	FillPath (double cosT, double phi)=0

virtual std::vector< NuPath >	GetNuPath ()

virtual std::vector< NuPath >	GetMergedPaths (double prec=0.25)
	Get merged path sequence in a vector. More...

virtual double	GetTotalL (double cosT)
	Get the total baseline for a given cosTheta. More...

virtual double	GetCosT (double L)
	Get the cosTheta for a given total baseline. More...

virtual void	SetRemoveSmallPaths (bool rp=true)
	Set tag to remove small paths. More...

Protected Member Functions
virtual void	SetDetectorCoordinates (double rad, double lat, double lon)

virtual void	AddPathSegment (double length, double density, double zoa, int index)
	Add a path segment to the sequence. More...

	ClassDef (EarthModelBase, 1)

Protected Attributes
std::vector< NuPath >	fNuPath
	The current neutrino path sequence. More...

double	fRadiusMax
	Maximum radius in Earth model (in km) More...

double	fDetRadius
	The radius where the detector sits (in km) More...

double	fDetLat
	The latitude (in rad) where the detector sits. More...

double	fDetLon
	The longitude (in rad) where the detector sits. More...

bool	fRemoveSmallPaths
	Tag whether to merge small paths. More...

Detailed Description

This abstract class provides the structure to able to produce path sequences through the Earth as a function of the azimuthal angle and cosine of the zenith angle with respect to the detector.

The detector can be positioned at any point within the Earth (except at the exact center), and the path sequences will take into account the fact that some layers are above the detector.

This class inherits from TObject and can be saved in ROOT files.

Author: rpestes@apc.in2p3.fr

Definition at line 27 of file EarthModelBase.h.

Member Function Documentation

◆ AddPathSegment()

void EarthModelBase::AddPathSegment	(	double	length,
		double	density,
		double	zoa,
		int	index
	)

protectedvirtual

Add a path segment to the sequence.

For a given EarthBin, adds a path of a given length in that material

Parameters

length	- The length of the path segment in km
density	- The density along the path segment
zoa	- Z/A along the path segment
index	- Index for the matter along the path segment

Definition at line 65 of file EarthModelBase.cxx.

{
  fNuPath.push_back(NuPath(length, density, zoa, index));
}

References fNuPath.

Referenced by OscProb::EarthModelBinned::AddPath(), and OscProb::PremModel::AddPath().

◆ ClassDef()

OscProb::EarthModelBase::ClassDef	(	EarthModelBase	,
		1
	)

protected

◆ FillPath()

virtual int OscProb::EarthModelBase::FillPath	(	double	cosT,
		double	phi
	)

pure virtual

Construct the neutrino path through the Earth having zenith angle defined by cosT and azimuthal angle phi.

Not implemented in base class. Fill the path sequence in a vector (phi in degrees)

Implemented in OscProb::EarthModelBinned, and OscProb::PremModel.

◆ GetCosT()

double EarthModelBase::GetCosT ( double L )

virtual

Get the cosTheta for a given total baseline.

Given a baseline, find the direction of the neutrino. This could be useful for experiments with fixed baselines for example.

The baseline must be within the range of possible values in this earth model. Will return vertical neutrinos otherwise.

Parameters

L	- The total baseline of the neutrino

Definition at line 99 of file EarthModelBase.cxx.

{
  if (L < fRadiusMax - fDetRadius) return 1;
  if (L > fRadiusMax + fDetRadius) return -1;
 
  return (fRadiusMax * fRadiusMax - fDetRadius * fDetRadius - L * L) /
         (2 * fDetRadius * L);
}

References fDetRadius, and fRadiusMax.

◆ GetMergedPaths()

vector< NuPath > EarthModelBase::GetMergedPaths ( double prec = 0.25 )

virtual

Merge similar paths to reduce number of steps

This method will merge consecutive paths and take their averages until it finds a large enough gap to start a new merged path.

The merged paths will be returned, and the original detailed path will not be changed and will stay stored as an attribute.

Parameters

prec	- The precision to merge paths in g/cm^3

Returns: The vector of merged path segments

Definition at line 121 of file EarthModelBase.cxx.

{
  // The output vector
  vector<NuPath> mergedPath;
 
  // Start with the first path
  NuPath path = fNuPath[0];
 
  // Track the total length
  double totL = 0;
 
  // Loop over all paths starting from second
  for (int i = 1; i < fNuPath.size(); i++) {
    // If this path electron density is beyond the tolerance
    if (fabs(path.density * path.zoa - fNuPath[i].density * fNuPath[i].zoa) >
        prec * path.zoa) {
      // Add merged path to vector
      mergedPath.push_back(path);
 
      // Set this path as new merged path
      path = fNuPath[i];
    }
    else { // If path is within tolerance
 
      // Merge the path with current merged path
      path = AvgPath(path, fNuPath[i]);
    }
 
    // Increment total length
    totL += fNuPath[i].length;
 
  } // End of loop over paths
 
  // Add the final merged path to vector
  mergedPath.push_back(path);
 
  // If tag is true, remove small paths
  if (fRemoveSmallPaths) {
    // Start at first path
    int k = 0;
 
    // While not at the end of vector
    while (k + 1 < mergedPath.size()) {
      // If length is less than 1% of total
      if (mergedPath[k].length < 0.01 * totL) {
        // Merge path with following path
        mergedPath = MergePaths(mergedPath, k, k + 1);
      }
      // If path is long enough skip it
      else
        k++;
 
    } // End of while loop
 
  } // End of if statement
 
  // return the merged vector
  return mergedPath;
}

References OscProb::AvgPath(), OscProb::NuPath::density, fNuPath, fRemoveSmallPaths, OscProb::MergePaths(), and OscProb::NuPath::zoa.

◆ GetNuPath()

vector< NuPath > EarthModelBase::GetNuPath ( )

virtual

Get the current neutrino path sequence

The path needs to be filled for a given cosTheta before calling this function.

Definition at line 52 of file EarthModelBase.cxx.

52{ return fNuPath; }

References fNuPath.

◆ GetTotalL()

double EarthModelBase::GetTotalL ( double cosT )

virtual

Get the total baseline for a given cosTheta.

Parameters

cosT	- The cosine of the neutrino direction

Definition at line 77 of file EarthModelBase.cxx.

{
  if (fabs(cosT) > 1) return 0;
 
  double sinsqrT = 1 - cosT * cosT;
 
  return -fDetRadius * cosT +
         sqrt(fRadiusMax * fRadiusMax - fDetRadius * fDetRadius * sinsqrT);
}

References fDetRadius, and fRadiusMax.

◆ SetDetectorCoordinates()

void EarthModelBase::SetDetectorCoordinates	(	double	rad,
		double	lat,
		double	lon
	)

protectedvirtual

Set the coordinates of the detector (rad = radius in km, lat/lon in deg)

Set the coordinates of the detector: radius in km, latitude in degrees, longitude in degrees

Parameters

rad	- The distance from the detector to the Earth's center in km
lat	- The latitude of the detector in deg N (between -90 and 90)
lon	- The longitude of the detector in deg E (between 0 and 360)

Definition at line 25 of file EarthModelBase.cxx.

{
  // Force radius to be non-negative
  if (rad < 0) {
    cerr << "WARNING: Negative radius detected. Setting to absolute value."
         << endl;
    rad = -rad;
  }
  fDetRadius = rad;
 
  // Force latitude to be between -90 and 90 deg
  lat -= floor((lat + 90.0) / 360.0) * 360.0;
  if (lat > 90) { lat = 180.0 - lat; }
  fDetLat = lat / 180.0 * M_PI; // convert to radians
 
  // Force longitude to be between 0 and 360 deg
  lon -= floor(lon / 360.0) * 360.0;
  fDetLon = lon / 180.0 * M_PI; // convert to radians
}