def __init__(self,
satellite_configuration,
groundstation_configuration,
channel_configuration,
monte_carlo=False,
warn=True):
# store the parameters internally
self.satellite_configuration = satellite_configuration
self.groundstation_configuration = groundstation_configuration
self.channel_configuration = channel_configuration
self.monte_carlo = monte_carlo
self.warn = warn
# if we're doing Monte-Carlo we need to choose an elevation to use
if self.monte_carlo:
distribution = channel_configuration['statistical']['geometry'][
'elevation']
assert distribution[0] == 'Uniform'
minimum_elevation = float(distribution[1][0])
maximum_elevation = float(distribution[1][1])
self.elevation = (maximum_elevation - minimum_elevation
) * random.random() + minimum_elevation
else:
self.elevation = channel_configuration['nominal']['geometry'][
'elevation']
# set the components
self.satellite_init()
self.groundstation_init()
self.channel_init()
# defaults to DVB-S2X
self.modulation = pylink.Modulation()
# form the downlink signal chain
self.downlink = pylink.DAGModel([
self.geometry, self.gs_rx_antenna, self.sat_transmitter,
self.sat_tx_antenna, self.gs_receiver, self.downlink_channel,
self.rx_interconnect, self.tx_interconnect, self.modulation,
pylink.LinkBudget(name='Downlink', is_downlink=True)
])
# form the downlink signal chain
self.uplink = pylink.DAGModel([
self.geometry, self.sat_rx_antenna, self.sat_receiver,
self.gs_transmitter, self.gs_tx_antenna, self.uplink_channel,
pylink.LinkBudget(name='Uplink', is_downlink=False)
])
def model():
return pylink.DAGModel([pylink.Geometry(),
pylink.Antenna(is_rx=True),
pylink.Interconnect(is_rx=True),
pylink.Receiver(),
pylink.Transmitter(),
pylink.Interconnect(is_rx=False),
pylink.Antenna(is_rx=False),
pylink.Channel(),
pylink.Modulation(name='QPSK', perf=perf),
pylink.LinkBudget()])
def update_gs_rx_antenna_gain(self, gain):
# create new antenna
self.gs_rx_antenna = pylink.Antenna(
gain=gain,
pattern=self.sampler(self.groundstation_configuration,
['rx', 'antenna', 'pattern']),
polarization=self.groundstation_configuration['nominal']['rx']
['antenna']['polarization'],
is_rx=True,
tracking=self.groundstation_configuration['nominal']['rx']
['antenna']['tracking'],
pointing_loss_db=self.sampler(self.groundstation_configuration,
['rx', 'antenna', 'pointing_loss']),
rx_noise_temp_k=self.sampler(self.groundstation_configuration,
['rx', 'antenna', 'noise_temp']))
# form the downlink signal chain
self.downlink = pylink.DAGModel([
self.geometry, self.gs_rx_antenna, self.sat_transmitter,
self.sat_tx_antenna, self.gs_receiver, self.downlink_channel,
self.rx_interconnect, self.tx_interconnect, self.modulation,
pylink.LinkBudget(name='Downlink', is_downlink=True)
])
center_freq_mhz=8200,
atmospheric_loss_db=1,
ionospheric_loss_db=1,
rain_loss_db=2,
multipath_fading_db=0,
polarization_mismatch_loss_db=3)
s_channel = pylink.Channel(bitrate_hz=500e3,
allocation_hz=5e6,
center_freq_mhz=2022.5,
atmospheric_loss_db=.5,
ionospheric_loss_db=.5,
rain_loss_db=1,
multipath_fading_db=0,
polarization_mismatch_loss_db=3)
# defaults to DVB-S2X
modulation = pylink.Modulation()
DOWNLINK = pylink.DAGModel([
geometry, gs_rx_antenna, sat_transmitter, sat_tx_antenna, gs_receiver,
x_channel, rx_interconnect, tx_interconnect, modulation,
pylink.LinkBudget(name='Example XBand Downlink', is_downlink=True)
])
UPLINK = pylink.DAGModel([
geometry, sat_rx_antenna, sat_receiver, gs_transmitter, gs_tx_antenna,
s_channel,
pylink.LinkBudget(name='Example SBand Uplink', is_downlink=False)
])
Nodes are added to the DAG in the order in which they are received.
So you can, if you wish, override a standard definition.
"""
# Vanilla link budget
m = pylink.DAGModel([
pylink.Geometry(),
pylink.Transmitter(tx_power_at_pa_dbw=2),
pylink.Interconnect(is_rx=False),
pylink.Antenna(is_rx=False),
pylink.Receiver(),
pylink.Antenna(is_rx=True),
pylink.Interconnect(is_rx=True),
pylink.Channel(),
pylink.Modulation('DVB-S2X'),
pylink.LinkBudget()
])
e = m.enum
print 'Link margin in vanilla example: %s' % m.link_margin_db
# let's override the link_margin_db node in the kwargs
def _evil_margin_db(model):
return -3.0
m = pylink.DAGModel([
pylink.Geometry(),
pylink.Transmitter(tx_power_at_pa_dbw=2),
pylink.Interconnect(is_rx=False),
atmospheric_loss_db=1,
ionospheric_loss_db=1,
rain_loss_db=2,
multipath_fading_db=0,
polarization_mismatch_loss_db=3)
modulation = pylink.Modulation()
DOWNLINK = pylink.DAGModel([geometry,
gs_rx_antenna,
sat_transmitter,
sat_tx_antenna,
gs_receiver,
ka_channel,
rx_interconnect,
tx_interconnect,
modulation,
pylink.LinkBudget(name='Ka Downlink',
is_downlink=True)])
UPLINK = pylink.DAGModel([geometry,
sat_rx_antenna,
sat_receiver,
gs_transmitter,
gs_tx_antenna,
ka_channel,
modulation,
pylink.LinkBudget(name='Ka Uplink',
is_downlink=False)])
}
tx_power = TA(2,
part_number='234x',
test_report='http://reports.co/234x')
m = pylink.DAGModel([pylink.Geometry(),
pylink.Transmitter(tx_power_at_pa_dbw=tx_power),
pylink.Interconnect(is_rx=False),
pylink.Antenna(is_rx=False),
pylink.Receiver(),
pylink.Antenna(is_rx=True),
pylink.Interconnect(is_rx=True),
pylink.Channel(),
pylink.Modulation('DVB-S2X'),
pylink.LinkBudget()],
**ex)
e = m.enum
print('slant range (km): %3g' % m.slant_range_km)
print('antenna angle (deg): %3g' % m.satellite_antenna_angle_deg)
print('total rx noise temp (K): %3g' % m.rx_noise_temp_k)
print('receiver noise temp (K): %3g' % m.rx_system_noise_temp_k)
print('noise factor: %3g' % m.rx_system_noise_factor)
print('noise figure (dB): %3g' % m.rx_system_noise_figure)
print('transmit power (dBW): %3g' % m.tx_power_at_antenna_dbw)
print('transmit eirp (dBW): %3g' % m.tx_eirp_dbw)
print('UGPL (dB): %3g' % m.unity_gain_propagation_loss_db)
print('Total Channel Loss (dB): %3g' % m.total_channel_loss_db)
print('Link Margin (dB): %3g' % m.link_margin_db)
print('Noise BW Loss (dB): %-3g' % m.excess_noise_bandwidth_loss_db)
