def getOwlt(utc_time): '''Uses novas module to compute One Way Light Time at given UTC time.''' jd_start, jd_end, number = eph_manager.ephem_open() jd_tt = novas.julian_date(utc_time.tm_year, utc_time.tm_mon, utc_time.tm_mday, utc_time.tm_hour) mars = novas.make_object(0, 4, 'Mars', None) ra, dec, dis = novas.astro_planet(jd_tt, mars) au_sec = 499.0047838061 # Light-time for one astronomical unit (AU) in seconds, from DE-405 owlt = dis * au_sec return owlt
def print_planet(planet_name, planet_num):
# make_object(type, number, name, star)
# type = 0;major planet, Pluto, Sun, or Moon
# type = 1; minor planet
# type = 2; object located outside the soloar system
# number; Mercury = 1, ..., Pluto = 9, Sun = 10, Moon = 11
print planet_name
planet = novas.make_object(0, planet_num, planet_name, None)
ra, dec, dis = novas.astro_planet(jd_tt, planet)
print 'R.A. %d:%02f' % (ra, abs(ra) % 1. * 60.)
print 'dec. %d:%02f' % (dec, abs(dec) % 1. * 60.)
print 'distance %f AU' % (dis,)
def test_astro_planet(self):
for jd_tt, name in product([T0, TA, TB], planets_to_test):
obj = c.make_object(0, planet_codes[name], 'planet', None)
ra, dec, dis = c.astro_planet(jd_tt, obj)
earth = self.e.earth
planet = getattr(self.e, name)
jd = JulianDate(tt=jd_tt)
g = planet.observe_from(earth(jd)).astrometric()
self.eq(ra * tau / 24.0, g.ra, 0.001 * arcsecond)
self.eq(dec * tau / 360.0, g.dec, 0.001 * arcsecond)
self.eq(dis, g.distance, 0.001 * meter)
def test_astro_planet(jd, planet_name_and_code):
planet_name, planet_code = planet_name_and_code
obj = c.make_object(0, planet_code, 'planet', None)
ra0, dec0, distance0 = c.astro_planet(jd.tt, obj)
earth = de405.earth
planet = getattr(de405, planet_name)
e = earth(jd)
distance = length_of((e - planet(jd)).position.AU)
ra, dec, d = e.observe(planet).radec()
eq(ra0, ra.hours(), 1e-3 * arcsecond_in_hours)
eq(dec0, dec.degrees(), 1e-3 * arcsecond_in_degrees)
eq(distance0, distance, 0.5 * meter)
def test_astro_planet(timepairs, planets_list):
jd_tt = timepairs[0]
planet_name = planets_list[0]
planet_code = planets_list[1]
obj = c.make_object(0, planet_code, 'planet', None)
ra, dec, dis = c.astro_planet(jd_tt, obj)
earth = emp.earth
planet = getattr(emp, planet_name)
jd = JulianDate(tt=jd_tt)
g = planet.observe_from(earth(jd)).astrometric()
eq(ra * TAU / 24.0, g.ra, 0.001 * arcsecond)
eq(dec * TAU / 360.0, g.dec, 0.001 * arcsecond)
eq(dis, g.distance, 0.001 * meter)