def get_next_pass(self,
location,
when_utc=None,
max_elevation_gt=5,
aos_at_dg=0,
limit_date=None):
"""Return a PredictedPass instance with the data of the next pass over the given location
location_llh: point on Earth we want to see from the satellite.
when_utc: datetime UTC after which the pass is calculated, default to now.
max_elevation_gt: filter passes with max_elevation under it.
aos_at_dg: This is if we want to start the pass at a specific elevation.
The next pass with a LOS strictly after when_utc will be returned,
possibly the current pass.
"""
if when_utc is None:
when_utc = dt.datetime.utcnow()
for pass_ in self.passes_over(location,
when_utc,
limit_date,
max_elevation_gt=max_elevation_gt,
aos_at_dg=aos_at_dg):
return pass_
else:
raise NotReachable('Propagation limit date exceeded')
def get_next_pass(self, location, when_utc=None, max_elevation_gt=5,
aos_at_dg=0, limit_date=None):
"""Implements same api as standard predictor"""
if when_utc is None:
when_utc = datetime.datetime.utcnow()
for pass_ in self.passes_over(location, when_utc, limit_date,
max_elevation_gt=max_elevation_gt,
aos_at_dg=aos_at_dg):
return pass_
else:
raise NotReachable('Propagation limit date exceded')
def _get_next_pass(self, location, when_utc, aos_at_dg=0, limit_date=None):
if not isinstance(location, Location):
raise TypeError("location must be a Location instance")
pass_ = PredictedPass(location=location,
sate_id=self.sate_id,
aos=None,
los=None,
max_elevation_date=None,
max_elevation_position=None,
max_elevation_deg=0,
duration_s=0)
seconds = 0
self._iterations = 0
while True:
# to optimize the increment in seconds must be inverse proportional to
# the distance of 0 elevation
date = when_utc + datetime.timedelta(seconds=seconds)
if limit_date is not None and date > limit_date:
raise NotReachable('Propagation limit date exceded')
elev_pos = self.get_position(date)
_, elev = location.get_azimuth_elev(elev_pos)
elev_deg = degrees(elev)
if elev_deg > pass_.max_elevation_deg:
pass_.max_elevation_position = elev_pos
pass_.max_elevation_date = date
pass_.max_elevation_deg = elev_deg
if elev_deg > aos_at_dg and pass_.aos is None:
pass_.aos = date
if pass_.aos and elev_deg < aos_at_dg:
pass_.los = date
pass_.duration_s = (pass_.los - pass_.aos).total_seconds()
break
if elev_deg < -2:
delta_s = abs(elev_deg) * 15 + 10
else:
delta_s = 20
seconds += delta_s
self._iterations += 1
return pass_