Example - 61 - Compute v_inf and arrival declination from flyby dates (2)
In this example, we compute the arrival v_inf and declination from a trajectory whose last flyby and arrival dates are known.
Note: This examples requires
poliastro to be installed. These are not installed by default when AMAT is installed and must be installed separately using
pip install astropy and
pip install poliastro.
import numpy as np from astropy.time import Time from AMAT.arrival import Arrival
In this example, we use the flyby dates from Option 5: Uranus Orbiter Concept with Probe presented in the NASA Ice-Giants Pre-Decadal Study Report.
arrival = Arrival() arrival.set_vinf_vec_from_lambert_arc(lastFlybyPlanet='JUPITER', arrivalPlanet='URANUS', lastFlybyDate=Time("2036-03-28 00:00:00", scale='tdb'), arrivalDate=Time("2043-05-17 00:00:00", scale='tdb'))
print("Arrival v_inf vector, ICRF: "+str(arrival.v_inf_vec)+" km/s")
Arrival v_inf vector, ICRF: [-4.0742798 6.69346343 3.04912046] km/s
print("Arrival v_inf magnitude: "+str(round(arrival.v_inf_mag, 2))+" km/s.")
Arrival v_inf magnitude: 8.41 km/s.
print("Arrival Declination: "+str(round(arrival.declination, 2))+" deg.")
Arrival Declination: -47.88 deg.
Compare with values in page 406 of the NASA Ice-Giants Pre-Decadal Study Report.