G_ali                   Albedo-reflected irradiance on Mars inclined
                        surface
G_b                     Direct beam irradiance on Mars surface normal
                        to solar rays
G_bh                    Direct beam irradiance on Mars horizontal
                        surface
G_bi                    Direct beam irradiance on Mars inclined surface
G_dh                    Diffuse irradiance on Mars horizontal surface
G_di                    Diffuse irradiance on Mars inclined surface
G_h                     Global irradiance on Mars horizontal surface
G_i                     Global irradiance on Mars inclined surface
G_ob                    Beam irradiance at top of Martian atmosphere
G_obh                   Beam irradiance on horizontal surface at top of
                        Mars atmosphere
H_ali                   Albedo-reflected daily insolation on Mars
                        inclined surface
H_bh                    Beam daily insolation on Mars horizontal
                        surface
H_bi                    Beam daily insolation on Mars inclined surface
H_dh                    Diffuse daily insolation on Mars horizontal
                        surface
H_di                    Diffuse daily insolation on Mars inclined
                        surface
H_h                     Global daily insolation on Mars horizontal
                        surface
H_i                     Global daily insolation on Mars inclined
                        surface
H_obh                   Daily beam insolation at top of Mars atmosphere
I_ali                   Albedo-reflected insolation on Mars inclined
                        surface over time period
I_bh                    Beam insolation on Mars horizontal surface over
                        time period
I_bi                    Beam insolation on Mars inclined surface over
                        time period
I_dh                    Diffuse insolation on Mars horizontal surface
                        over time period
I_di                    Diffuse insolation on Mars inclined surface
                        over time period
I_h                     Global insolation on Mars horizontal surface
                        over time period
I_i                     Global insolation on Mars inclined surface over
                        time period
I_obh                   Beam insolation at top of Mars atmosphere over
                        time period
T_d                     Number of Mars daylight hours
Z                       Solar zenith angle
albedo                  The albedo function.
declination             Solar declination angle on Mars
f                       Normalized net flux function
is_irradiated           Check if surface is receiving solar irradiance
is_polar_day            Check if location is experiencing polar day
is_polar_night          Check if location is experiencing polar night
marsrad-package         marsrad: Mars Solar Radiation
optical_depth           Atmospheric optical depth on Mars
optimal_angle           Optimal tilt angle for maximum daily insolation
sunrise                 Sunrise time on Mars
sunset                  Sunset time on Mars
