ROIs seen by MAJIS during GCO5000

Example of opportunities for MAJIS to observe Ganymede ROIs during GCO5000 phase.

import matplotlib.pyplot as plt

from planetary_coverage import GANYMEDE, GanymedeROIs, TourConfig, read_events
from planetary_coverage.misc import wget
from planetary_coverage.ticks import deg_ticks

Download JUICE mission phases from the SOC

URL = 'https://juicesoc.esac.esa.int/data/DATA/crema_5_0'
MISSION_PHASES = 'Mission_Phases.csv'

wget(f'{URL}/{MISSION_PHASES}', MISSION_PHASES, skip=True)

PosixPath('Mission_Phases.csv')

Get GCO 5000 windows from the mission phases

phases = read_events(MISSION_PHASES)

gco_5000 = phases['GCO5000']

gco_5000

column_0	Ganymede_Phase_6_2
name	GCO5000
t_start	2035-01-17T03:00:00
t_end	2035-04-16T16:00:00
column_4

Load JUICE trajectory during GCO 5000

tour = TourConfig(mk='5.1 150lb', spacecraft='JUICE', instrument='MAJIS',
                  target='Ganymede', version='v400')

majis_gco_5000 = tour[gco_5000:'15 min']

majis_gco_5000

<InstrumentTrajectory> Observer: JUICE_MAJIS | Target: GANYMEDE
 - UTC start time: 2035-01-17T03:00:00.000
 - UTC stop time: 2035-04-16T16:00:00.000
 - Nb of pts: 8,598

Keep only the part of the trajectory well lighted

traj = majis_gco_5000.where(majis_gco_5000.inc < 70)

traj

<MaskedInstrumentTrajectory> Observer: JUICE_MAJIS | Target: GANYMEDE
 - First UTC start time: 2035-01-17T03:00:00.000
 - Last UTC stop time: 2035-04-13T06:29:59.998
 - Nb of pts: 1,819 (+6,779 masked)
 - Nb of segments: 158

Find the ROIs intersected by the trajectory

traj_in_rois = traj & GanymedeROIs

traj_in_rois

<MaskedInstrumentTrajectory> Observer: JUICE_MAJIS | Target: GANYMEDE
 - First UTC start time: 2035-01-17T03:30:00.000
 - Last UTC stop time: 2035-04-13T05:59:59.998
 - Nb of pts: 703 (+7,895 masked)
 - Nb of segments: 369

rois_visible = GanymedeROIs & traj
rois_not_visible = GanymedeROIs ^ traj

len(GanymedeROIs), len(rois_visible), len(rois_not_visible)

(139, 118, 21)

(
    f'{len(rois_visible) / len(GanymedeROIs):.0%} of Ganymede ROIs are '
    'visible with MAJIS with an incidence lower than 70° during GCO 5000.'
)

'85% of Ganymede ROIs are visible with MAJIS with an incidence lower than 70° during GCO 5000.'

Represent the intersection opportunities on the map

fig = plt.figure(figsize=(12, 9))
ax = fig.add_subplot(projection=GANYMEDE)

ax.add_collection(traj_in_rois.fovs(facecolors='inc', vmin=45, vmax=70, sort='inc'))

ax.add_collection(rois_visible(edgecolors='red'))
ax.add_collection(rois_not_visible(edgecolors='white', linewidths=1, linestyles='--'))

ax.colorbar(vmin=45, vmax=70, label='inc')
ax.twin_colorbar(label='Solar elevation', format=90 - deg_ticks)
ax.set_title('MAJIS coverage opportunities during GCO 5000 (downlink windows excluded)')

plt.show()

Download

• majis_gco_5000.ipynb

• majis_gco_5000.py