0.0.2 Multi-Boresight (2026-02-23)

New Features

  • Multi-Boresight Support: Satellites can now define multiple named boresights for different payloads and instruments

    • Boresight argument now accepts a dictionary mapping names to 3D vectors

    • Goals can reference specific boresights via the boresight_name parameter

    • Fully backward compatible with single boresights (np.ndarray)

  • Backward Compatibility

    • Passing np.ndarray as a boresight: automatically registered as "default"

    • Passing None: defaults to (0, 0, 1) and registered as "default"

  • Added boresight_hist field to simulation results in both ADCS.simulate and ADCS.simulate_mc

Example: Multi-Boresight Single-Run Simulation

Consider a satellite with multiple instruments pointing in different directions, using a fixed-attitude goal followed by goals that reference specific boresights.

import ADCS as ADCS
import numpy as np
import matplotlib.pyplot as plt

np.random.seed(42)
mtm_max_torque = 0.1
mtqs = [ADCS.MTQ(axis=axes, max_torque=mtm_max_torque) for axes in np.eye(3)]

rw_max_torque = 4.51
rw_J = 0.22
rw_h0 = 1
rw_hmax = 3.8
rws = [ADCS.RW(axis=axes, max_torque=rw_max_torque, J=rw_J, h=rw_h0, h_max=rw_hmax) for axes in np.eye(3)]

acts = mtqs + rws
mtms = [ADCS.MTM(axis=axes) for axes in np.eye(3)]

# Define multiple boresights for different instruments
boresights = {
    "camera": np.array([0, 0, 1]),
    "solar_panel": np.array([1, 0, 0])
}

real_sat = ADCS.Satellite(
    mass=4.0,
    J_0=np.diagflat([3.4, 2.9, 1.3]),
    actuators=acts,
    sensors=mtms,
    boresight=boresights
)
x_0 = np.array([0, 0, 0] + [1, 0, 0, 0] + [0, 0, 0])

controller = ADCS.controller.MTQ_w_RW(
    est_sat=real_sat,
    p_gain=0.1,
    d_gain=0.7,
    c_gain=0.1,
    h_target=np.array([0, 0, 0])
)

# Define goals that reference specific boresights
goal_timeline = {
    0.0: ADCS.goals.Fixed_Attitude_Goal(q_ref=np.array([0, 0, 0, 1])),
    100.0: ADCS.goals.Coordinate_Goal(lat=33.75, lon=-84.3885, alt=0, boresight_name="camera"),
    200.0: ADCS.goals.AntiVelocity_Goal(boresight_name="solar_panel"),
    300.0: ADCS.goals.Sun_Goal(boresight_name="solar_panel")
}
goallist = ADCS.GoalList(
    goal_timeline=goal_timeline,
    time_units="seconds",
    start_juliantime=0.22
)

os0 = ADCS.Orbital_State(
    ephem=ADCS.Ephemeris(),
    J2000=0.22,
    R=np.array([7000, 0, 0]),
    V=np.array([0, 7.5, 0])
)

results = ADCS.simulate(
    x=x_0,
    satellite=real_sat,
    controller=controller,
    goal=goallist,
    os0=os0,
    dt=1.0,
    tf=1000.0
)

ADCS.plot(
    results,
    ADCS.plots.ControlPlot(),
    ADCS.plots.TargetPlot(modes=["real_target"]),
    ADCS.plots.TargetHistogram(),
    ADCS.plots.IlluminationPlot(),
    layout=(2, 2),
    title="Control Plot",
)

plt.show()
Alignment with Camera Axis Alignment with Solar Panel Axis Error Plots

As can be seen in the plots, the satellite successfully aligns with the camera boresight during the coordinate goal and then reorients to align the solar panel boresight for the anti-velocity and sun goals, demonstrating the multi-boresight functionality in action.

Backward Compatibility

The multi-boresight feature is fully backward compatible:

Single boresight as ``np.ndarray``:

real_sat = ADCS.Satellite(
    mass=4.0,
    J_0=np.diagflat([3.4, 2.9, 1.3]),
    actuators=acts,
    sensors=mtms,
    boresight=np.array([0, 0, 1])  # Automatically named "default"
)

No boresight specified:

real_sat = ADCS.Satellite(
    mass=4.0,
    J_0=np.diagflat([3.4, 2.9, 1.3]),
    actuators=acts,
    sensors=mtms
    # boresight defaults to (0, 0, 1) as "default"
)

Both forms register the boresight as "default", allowing goals to use boresight_name="default" or rely on the default behavior when no boresight name is specified.