MoonHandler.py

import spiceypy as spice
import numpy as np
import math

spice.furnsh('../resources/naif0012.tls')  # Load the leap seconds kernel
spice.furnsh('../resources/de430.bsp')  # Load the ephemeris file


class MoonHandler():
    @staticmethod
    def calculate_positions(time):
        et = spice.str2et(time)
        pos_moon, _ = spice.spkpos('MOON', et, 'J2000', 'NONE', 'EARTH')
        pos_sun, _ = spice.spkpos('SUN', et, 'J2000', 'NONE', 'EARTH')
        return pos_moon, pos_sun

    @staticmethod
    def calculate_RA_vector(pos):
        x, y, _ = pos
        RA = math.degrees(math.atan2(y, x))
        return RA
    
    @staticmethod
    def calculate_distance(pos_moon):
        return np.linalg.norm(pos_moon)

    @staticmethod
    def phase(pos_moon, pos_sun):
        RA_moon = MoonHandler.calculate_RA_vector(pos_moon)
        RA_sun = MoonHandler.calculate_RA_vector(pos_sun)

        O = math.acos(
            np.dot(pos_moon, pos_sun) /
            (np.linalg.norm(pos_moon[:2]) * np.linalg.norm(pos_sun[:2]))
        )
        O_degrees = math.degrees(O)
        
        if RA_moon < RA_sun:
            O_degrees = -O_degrees
        return O_degrees
    
    @staticmethod
    def brightness(phase, distance):
        return ((abs(phase)/180)*(pow(distance/356500,2)))/1.3