Exemplo n.º 1
0
def compare_perturbers_orekit():
    f, ax = plt.subplots(2, 1)

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )

    trySentinel1_compare(
        ax,
        sv,
        'no solarsystem perturbers',
        C_D=2.3,
        C_R=1.0,
        radiation_pressure=True,
        solarsystem_perturbers=[],
    )
    trySentinel1_compare(
        ax,
        sv,
        'Moon + sun perturbers',
        C_D=2.3,
        C_R=1.0,
        radiation_pressure=True,
        solarsystem_perturbers=['Moon', 'Sun'],
    )
    ax[0].set_title(
        'Errors from propagation: Third body perturbations comparison')
    ax[0].set_ylabel('Position error [m]')
    ax[1].set_ylabel('Velocity error [m/s]')
    ax[1].set_xlabel('Time [h]')
    ax[0].legend()
    plt.show()
Exemplo n.º 2
0
def compare_grav_orekit():
    f, ax = plt.subplots(2, 1)

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )

    trySentinel1_compare(
        ax,
        sv,
        'Newtonian grav',
        C_D=2.3,
        C_R=1.0,
        radiation_pressure=True,
        earth_gravity='Newtonian',
    )
    trySentinel1_compare(
        ax,
        sv,
        'HolmesFeatherstone grav',
        C_D=2.3,
        C_R=1.0,
        radiation_pressure=True,
        earth_gravity='HolmesFeatherstone',
    )
    ax[0].set_title('Errors from propagation: gravity model')
    ax[0].set_ylabel('Position error [m]')
    ax[1].set_ylabel('Velocity error [m/s]')
    ax[1].set_xlabel('Time [h]')
    ax[0].legend()
    plt.show()
Exemplo n.º 3
0
def compare_C_D_orekit():

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )
    N = len(sv)
    t = 10 * np.arange(N)

    f, ax = plt.subplots(2, 1)
    trySentinel1_compare(
        ax,
        sv,
        'C_D = 1.6',
        C_D=1.6,
        C_R=1.0,
        radiation_pressure=True,
    )
    pv = trySentinel1_compare(
        ax,
        sv,
        'C_D = 2.3',
        C_D=2.3,
        C_R=1.0,
        radiation_pressure=True,
    )
    trySentinel1_compare(
        ax,
        sv,
        'C_D = 3.0',
        C_D=3.0,
        C_R=1.0,
        radiation_pressure=True,
    )
    ax[0].set_title('Errors from propagation: drag coefficient comparison')
    ax[0].set_ylabel('Position error [m]')
    ax[1].set_ylabel('Velocity error [m/s]')
    ax[1].set_xlabel('Time [h]')
    '''
    ax2 = ax[0].twinx()

    ax2.plot(t/3600., np.linalg.norm(pv[:3].T, axis=1), 'b.', alpha=0.25)
    ax2.set_ylabel('Orbital radius', color='b')
    ax2.tick_params('y', colors='b')
    '''
    f.tight_layout()

    ax[0].legend()
    plt.show()
Exemplo n.º 4
0
def compare_effects_orekit():
    f, ax = plt.subplots(2, 1)

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )

    trySentinel1_compare(
        ax,
        sv,
        'No tidal, No PR',
        C_D=2.3,
        C_R=1.0,
        frame_tidal_effects=False,
        radiation_pressure=False,
    )
    trySentinel1_compare(
        ax,
        sv,
        'No tidal, PR',
        C_D=2.3,
        C_R=1.0,
        frame_tidal_effects=False,
        radiation_pressure=True,
    )
    trySentinel1_compare(
        ax,
        sv,
        'Tidal, PR',
        C_D=2.3,
        C_R=1.0,
        frame_tidal_effects=True,
        radiation_pressure=True,
    )
    ax[0].set_title('Errors from propagation: tidal and radiation effect')
    ax[0].set_ylabel('Position error [m]')
    ax[1].set_ylabel('Velocity error [m/s]')
    ax[1].set_xlabel('Time [h]')
    ax[0].legend()
    plt.show()
Exemplo n.º 5
0
def trySentinel1(**kw):

    p = PropagatorOrekit(
        in_frame='ITRF',
        out_frame='ITRF',
        frame_tidal_effects=True,
        #earth_gravity='Newtonian',
        #radiation_pressure=False,
        #solarsystem_perturbers=[],
        #drag_force=False,
    )

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )

    x, y, z = sv[0].pos
    vx, vy, vz = sv[0].vel
    mjd0 = (sv[0]['utc'] - np.datetime64('1858-11-17')) / np.timedelta64(
        1, 'D')

    N = len(sv)
    t = 10 * np.arange(N)

    kwargs = dict(m=2300., C_R=0., C_D=.0, A=4 * 2.3)
    kwargs.update(**kw)

    pv = p.get_orbit_cart(t, x, y, z, vx, vy, vz, mjd0, **kwargs)

    perr = np.linalg.norm(pv[:3].T - sv.pos, axis=1)
    verr = np.linalg.norm(pv[3:].T - sv.vel, axis=1)

    f, ax = plt.subplots(2, 1)
    ax[0].plot(t / 3600., perr)
    ax[0].set_title('Errors from propagation')
    ax[0].set_ylabel('Position error [m]')
    ax[1].plot(t / 3600., verr)
    ax[1].set_ylabel('Velocity error [m/s]')
    ax[1].set_xlabel('Time [h]')
Exemplo n.º 6
0
o_nept = dict()
p_orekit = PropagatorOrekit
o_orekit = dict(
    in_frame='TEME',
    out_frame='ITRF',
)

props = [
    (p_sgp4, o_sgp4),
    (p_nept, o_nept),
    #    (p_orekit,o_orekit),
]

# wtf is this?
sv, _, _ = over.read_poe(
    'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
)

sv = sv[:8641]

x, y, z = sv[0].pos / 1e3
vx, vy, vz = sv[0].vel / 1e3
mjd0 = (sv[0]['utc'] - np.datetime64('1858-11-17')) / np.timedelta64(1, 'D')

_alph = 0.75

N = len(sv)
t = 10 * np.arange(N)

fig, axs = plt.subplots(2, 1)
Exemplo n.º 7
0
def trySentinel1_array(**kw):

    p = PropagatorOrekit(
        in_frame='ITRF',
        out_frame='ITRF',
        frame_tidal_effects=True,
        #earth_gravity='Newtonian',
        #radiation_pressure=False,
        #solarsystem_perturbers=[],
        #drag_force=False,
    )

    sv, _, _ = over.read_poe(
        'data/S1A_OPER_AUX_POEORB_OPOD_20150527T122640_V20150505T225944_20150507T005944.EOF'
    )

    x, y, z = sv[0].pos
    vx, vy, vz = sv[0].vel
    mjd0 = (sv[0]['utc'] - np.datetime64('1858-11-17')) / np.timedelta64(
        1, 'D')

    N = len(sv)
    t = 10 * np.arange(N)

    num = []
    for _, item in kw.items():
        num.append(len(item))
    num = np.sum(num) / float(len(num))
    if np.abs(num - np.round(num)) < 1e-9:
        num = int(num)
    else:
        raise Exception('All vectors not equal length')

    perr = np.empty((N, num), dtype=np.float64)
    verr = np.empty((N, num), dtype=np.float64)

    kwargs = dict(m=2300., C_R=0., C_D=.0, A=4 * 2.3)

    comm = MPI.COMM_WORLD
    rank = comm.rank
    pool = comm.size

    my_range = list(range(rank, num, pool))

    for place, ind in enumerate(my_range):
        print('PID{}: {}/{} orbits done'.format(rank, place, len(my_range)))

        for key, item in kw.items():
            kwargs.update({key: item[ind]})

        pv = p.get_orbit_cart(t, x, y, z, vx, vy, vz, mjd0, **kwargs)

        perr[:, ind] = np.linalg.norm(pv[:3].T - sv.pos, axis=1)
        verr[:, ind] = np.linalg.norm(pv[3:].T - sv.vel, axis=1)

    if pool > 1:

        if rank == 0:
            print(
                '---> Thread {}: Receiving all results <barrier>'.format(rank))
            for T in range(1, pool):
                for ind in range(T, num, pool):
                    perr[:, ind] = comm.recv(source=T, tag=ind)
                    verr[:, ind] = comm.recv(source=T, tag=ind * 10)
        else:
            print(
                '---> Thread {}: Distributing all filter results to thread 0 <barrier>'
                .format(rank))
            for ind in my_range:
                comm.send(perr[:, ind], dest=0, tag=ind)
                comm.send(verr[:, ind], dest=0, tag=ind * 10)
        print('---> Distributing done </barrier>')

    if rank == 0:
        f, ax = plt.subplots(2, 1)
        for ind in range(num):
            ax[0].plot(t / 3600., perr[:, ind], '-b', alpha=0.01)
            ax[1].plot(t / 3600., verr[:, ind], '-b', alpha=0.01)

        ax[0].set_title('Errors from propagation')
        ax[0].set_ylabel('Position error [m]')
        ax[1].set_ylabel('Velocity error [m/s]')
        ax[1].set_xlabel('Time [h]')
        plt.show()