astroSpectra.hpp

Go to the documentation of this file.

/** \file astroSpectra.hpp
 * \author Jared R. Males
 * \brief Type definitions for the astronomical spectral libraries.
 * \ingroup astrophot
 *
 */
 
#ifndef mx_astro_astroSpectra_hpp
#define mx_astro_astroSpectra_hpp
 
#include "units.hpp"
#include "../ioutils/readColumns.hpp"
 
namespace mx
{
namespace astro
{
 
/// A basic spectrum
/**
 * \ingroup astrophot_spectra
 */
template <typename _units>
struct basicSpectrum
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The parameter is a string name.
 
    /// Specify how to convert to SI wavelength units. No conversions are performed in the basic spectrum
    static constexpr realT wavelengthUnits = static_cast<realT>( 1 );
 
    /// Specify how to convert to SI flux units. No conversions are performed in the basic spectrum
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    /// The data directory environment variable name.
    static constexpr const char *dataDirEnvVar = 0;
 
    /// This function should calculate the file name (without the path) for the spectrum parameters.
    static std::string
    fileName( const paramsT &name /**< [in] The parameters of the spectrum, in this case just its file name.*/ )
    {
        return name;
    }
 
    /// This function reads the spectrum, returning its raw wavelength and spectrum points.
    /** No unit conversions or interpolations should take place.
     */
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        return mx::ioutils::readColumns( path, rawLambda, rawSpectrum );
    }
};
 
/// A spectrum from the astroFilt filter library
/**
 * \ingroup astrophot_spectra
 */
template <typename _units, bool _rsr = true>
struct astroFilter
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The astroFilters are parameterized by name.
 
    /// Convert from um to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e6 );
 
    /// No conversion is performed on filter transmission.
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    static constexpr const char *dataDirEnvVar = "ASTROFILT_DATADIR";
 
    static std::string fileName( const std::string &name )
    {
        return name + ".dat";
    }
 
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        mx::ioutils::readColumns( path, rawLambda, rawSpectrum );
        realT max = 0;
 
        for( int i = 0; i < rawLambda.size(); ++i )
        {
            // if(_rsr) rawSpectrum[i] = rawSpectrum[i]*rawLambda[i];
            if( rawSpectrum[i] > max )
                max = rawSpectrum[i];
        }
 
        for( int i = 0; i < rawLambda.size(); ++i )
        {
            rawSpectrum[i] /= max;
        }
 
        return 0;
    }
};
 
/// A square-wave filter spectrum
/** Parameters specify the central wavelength, width, and sampling (all in microns) of a square-wave type filter.
 *
 * To create this filter:
 * \code
 * typedef double realT;
 *
 * realT lam0 = 0.5; //Central wavelength in microns
 * realT fw = 0.05; //Full-width, in microns.
 * realT dlam = 0.001; //Delta-lambda for specifying the defining points.  See note.
 *
 * astroSpectrum<sqWaveFilter<units::si<realT>>> filt({ lam0, fw, dlam});
 *
 * filt.setSpectrum(grid_meters); // grid_meters is a vector<realT> specifying the wavelength grid in meters
 *
 * \endcode
 *
 * Note that dlam specifies how sharp the filter edges are when interpolated.  Larger values will make the filter more
 * trapezoidal.
 *
 * \ingroup astrophot_spectra
 */
template <typename _units, bool _rsr = true>
struct sqWaveFilter
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    /// The square wave is parameterized by the central wavelength, width, and sampling (all in microns).
    typedef struct
    {
        realT lam0; ///< The central Wavelength in microns
        realT fw;   ///< The full width of the filter in microns
        realT dlam; ///< The wavelength sampling to use in microns.
    } paramsT;
 
    /// Convert from um to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e6 );
 
    /// No conversion is performed on filter transmission.
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    static constexpr const char *dataDirEnvVar = 0;
 
    static std::string fileName( const paramsT &params )
    {
        return " "; // must not be empty to avoid error
    }
 
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        rawLambda.resize( 4 );
        rawSpectrum.resize( 4 );
 
        rawLambda[0] = params.lam0 - 0.5 * params.fw - 0.5 * params.dlam;
        rawSpectrum[0] = 0.0;
 
        rawLambda[1] = params.lam0 - 0.5 * params.fw + 0.5 * params.dlam;
        rawSpectrum[1] = 1.0;
 
        rawLambda[2] = params.lam0 + 0.5 * params.fw - 0.5 * params.dlam;
        rawSpectrum[2] = 1.0;
 
        rawLambda[3] = params.lam0 + 0.5 * params.fw + 0.5 * params.dlam;
        rawSpectrum[3] = 0.0;
 
        return 0;
    }
};
 
/// A spectrum from the HST calspec library
/** See http://www.stsci.edu/hst/observatory/crds/calspec.html
 *
 * \ingroup astrophot_spectra
 */
template <typename _units>
struct calspecSpectrum
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The calspec Spectra are parameterized by star name.
 
    /// Convert from A to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e10 );
 
    /// Convert from erg s-1 cm-2 A-1 to SI W m-3
    static constexpr realT fluxUnits =
        static_cast<realT>( 1e7 ) / ( static_cast<realT>( 1e4 ) * static_cast<realT>( 1e10 ) );
 
    static constexpr const char *dataDirEnvVar = "CALSPEC_DATADIR";
 
    /// The file name is found from the star's name.
    static std::string fileName( const std::string &name )
    {
        if( name == "alpha_lyr" || name == "vega" )
            return "alpha_lyr_stis_005.asc";
        else if( name == "1740346" )
            return "1740346_nic_002.ascii";
        else if( name == "sun" || name == "sun_reference" )
            return "sun_reference_stis.002.asc";
    }
 
    /// Read a CALSPEC spectrum, which is a simple two column ASCII format.
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        return mx::ioutils::readColumns( path, rawLambda, rawSpectrum );
    }
};
 
/// A spectrum from the Pickles library
/**
 * \ingroup astrophot_spectra
 */
template <typename _units>
struct picklesSpectrum
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The Pickles spectra are parameterized by a spectral type string.
 
    /// Convert from A to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e10 );
 
    /// The Pickles spectra are dimensionless.
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    /// The Pickles spectra location is specified by the PICKLES_DATADIR environment variable.
    static constexpr const char *dataDirEnvVar = "PICKLES_DATADIR";
 
    /// The name of the datafile is constructed from its spectral type string.
    static std::string fileName( const std::string &spt )
    {
        return "uk" + ioutils::toLower( spt ) + ".dat";
    }
 
    /// Read a Pickles spectrum, which for these purposes is a simple two column ASCII format.
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        return mx::ioutils::readColumns( path, rawLambda, rawSpectrum );
    }
};
 
/// Earth Albedo Spectra
/** The spectra can be one of:
 * - "EPOXI" returns the apparent albedo spectrum from Cowan and Strait (2013) \cite cowan_2013.
 * - "RawEarthshine" returns the unormalized albedo spectrum measured using Earthshine by Turnbull et al (2006) \cite
 * turnbull_20016.
 * - "Earthshine" returns the Earthshine spectrum normalized to match the EPOXI result of 0.27 in the 550 nm band.
 *
 * \ingroup astrophot_spectra
 */
template <typename _units>
struct earthAlbedo
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The name of the spectrum can be "EPOXI", "Earthshine", or "RawEarthshine".
 
    /// Convert from A to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e6 );
 
    /// The Earthshine is a dimensionless albedo.
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    /// The location is specified by the EARTHSHINE_DATADIR environment variable.
    static constexpr const char *dataDirEnvVar = "EARTHSHINE_DATADIR";
 
    /// The name of the datafile is a constant.
    static std::string fileName( const std::string &name )
    {
        if( name == "EPOXI" )
            return "cowan_2013_EPOXI_albedo.dat";
        if( name == "Earthshine" )
            return "earthshine_epoxi_normalized.dat";
        if( name == "RawEarthshine" )
            return "Earthshine/F7_opt_NIR_ES_data.txt";
 
        mxError( "earthAlbeo::fileName", MXE_INVALIDARG, "name not recognized." );
 
        return "";
    }
 
    /// Read the Earthshine albedo spectrum, which is a simple two column ASCII format.
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        if( mx::ioutils::readColumns( path, rawLambda, rawSpectrum ) < 0 )
            return -1;
        return 0;
    }
};
 
/// Venus Spectra
/**
 *
 * \ingroup astrophot_spectra
 */
template <typename _units>
struct venusAlbedo
{
    typedef _units units;
    typedef typename units::realT realT;
 
    static const bool freq = false;
 
    typedef std::string paramsT; ///< The name of the spectrum can be "venus"
 
    /// Convert from A to SI m
    static constexpr realT wavelengthUnits = static_cast<realT>( 1e6 );
 
    /// The Earthshine is a dimensionless albedo.
    static constexpr realT fluxUnits = static_cast<realT>( 1 );
 
    /// The location is specified by the EARTHSHINE_DATADIR environment variable.
    static constexpr const char *dataDirEnvVar = "VENUS_DATADIR";
 
    /// The name of the datafile is a constant.
    static std::string fileName( const std::string &name )
    {
        if( name == "Venus" )
            return "venus_combined_albedo.dat";
 
        mxError( "venusAlbeo::fileName", MXE_INVALIDARG, "name not recognized." );
 
        return "";
    }
 
    /// Read the Earthshine albedo spectrum, which is a simple two column ASCII format.
    static int readSpectrum(
        std::vector<realT> &rawLambda,   ///< [out] the raw wavelength vector.  This should be an empty vector on input.
        std::vector<realT> &rawSpectrum, ///< [out] the raw spectrum.  This should be an empty vector on input.
        const std::string &path,         ///< [in] the full path to the file.
        const paramsT &params            ///< [in] the parameters are passed in case needed to construct the spectrum
    )
    {
        if( mx::ioutils::readColumns( path, rawLambda, rawSpectrum ) < 0 )
            return -1;
        return 0;
    }
};
 
} // namespace astro
 
} // namespace mx
 
#endif // mx_astro_astroSpectra_hpp