Exemple #1
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def Ede():
    loc = Observer()
    loc.horizon = "0"
    loc.lat = str(52.)
    loc.lon = str(5.6)
    loc.elevation = 24.5
    return loc
Exemple #2
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def setupobs(lla):
    obs = Observer()
    try:
        obs.lat = str(lla[0]); obs.lon = str(lla[1]); obs.elevation=float(lla[2])
    except ValueError:
        warn('observation location not specified. defaults to lat=0, lon=0')
    return obs
Exemple #3
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def iridium_tle(fn,T,sitella,svn):
    assert isinstance(svn,int)
    assert len(sitella)==3
    assert isinstance(T[0],datetime),'parse your date'

    fn = Path(fn).expanduser()
#%% read tle
    with fn.open('r') as f:
        for l1 in f:
            if int(l1[2:7]) == svn:
                l2 = f.readline()
                break
    sat = readtle('n/a',l1,l2)
#%% comp sat position
    obs = Observer()
    obs.lat = str(sitella[0]); obs.lon = str(sitella[1]); obs.elevation=float(sitella[2])

    ecef = DataFrame(index=T,columns=['x','y','z'])
    lla  = DataFrame(index=T,columns=['lat','lon','alt'])
    aer  = DataFrame(index=T,columns=['az','el','srng'])
    for t in T:
        obs.date = t
        sat.compute(obs)
        lat,lon,alt = degrees(sat.sublat), degrees(sat.sublong), sat.elevation
        az,el,srng = degrees(sat.az), degrees(sat.alt), sat.range
        x,y,z = geodetic2ecef(lat,lon,alt)
        ecef.loc[t,:] = column_stack((x,y,z))
        lla.loc[t,:]  = column_stack((lat,lon,alt))
        aer.loc[t,:]  = column_stack((az,el,srng))

    return ecef,lla,aer
 def distanceToSun(self):
     """
     Find the distance between the Sun and the target pointings
     """
     lofar = Observer()
     lofar.lon = '6.869882'
     lofar.lat = '52.915129'
     lofar.elevation = 15.*u.m
     lofar.date = self.startTime
     
     # Create Sun object
     sun = Sun()
     sun.compute(lofar)
     
     # Create the target object
     target = FixedBody()
     target._epoch = '2000'
     target._ra = self.coordPoint1.ra.radian
     target._dec = self.coordPoint1.dec.radian
     target.compute(lofar)
     print 'INFO: Sun is {:0.2f} degrees away from {}'.format(\
           float(separation(target, sun))*180./np.pi, self.namePoint1)
     target._ra = self.coordPoint2.ra.radian
     target._dec = self.coordPoint2.dec.radian
     target.compute(lofar)
     print 'INFO: Sun is {:0.2f} degrees away from {}'.format(\
           float(separation(target, sun))*180./np.pi, self.namePoint2)
Exemple #5
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def get_dutch_lofar_object():
    """Return an ephem.Observer() object with details containing the Dutch
       Lofar array"""
    lofar = Observer()
    lofar.lon = '6.869882'
    lofar.lat = '52.915129'
    lofar.elevation = 15.
    return lofar
Exemple #6
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def setupobs(obslla):
    assert len(obslla) == 3
    obs = Observer()
    obs.lat = str(obslla[0])  # STRING or wrong result! degrees
    obs.lon = str(obslla[1])  # STRING or wrong result! degrees
    obs.elevation = obslla[2]  # meters

    return obs
Exemple #7
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    def __init__(self,
                 name,
                 lat,
                 lon,
                 rot_ang=Angle(0.0, 'rad'),
                 elevation=0.0,
                 outrigger_delay=0.0):

        if not isinstance(lat, Latitude):
            raise TypeError, 'lat must be an instance of astropy.coordinates.Latitude'
        elif not isinstance(lon, Longitude):
            raise TypeError, 'lon must be an instance of astropy.coordintes.Latitude'

        self.isNull = False
        self.name = name
        self.lat = lat
        self.lon = lon
        self.rot_ang = rot_ang
        self.FOV_radius = Angle(23, unit='deg')
        self.alt_min = Angle(90.0, 'deg') - self.FOV_radius
        self.outrigger_delay = outrigger_delay

        #calculate range of declinations
        self.minDec = self.lat - self.FOV_radius
        self.maxDec = self.lat + self.FOV_radius

        #setup ephem.Observer representation
        self.observer = Observer()
        self.observer.lon = self.lon.deg.__str__()
        self.observer.lat = self.lat.deg.__str__()
        self.observer.elevation = elevation
Exemple #8
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 def test_moon_day_calculation_twelve(self, observer: Observer, moon: Moon,
                                      dt, number):
     moon.use_twelve_algorithm = True
     observer.date = dt
     moon.compute(observer)
     assert moon.get_day()['number'] == number, (dt,
                                                 moon.get_day()['number'],
                                                 number)
Exemple #9
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    def setUp(self):
        self.date = Date('1955/05/21')

        self.obs = obs = Observer()
        obs.lat, obs.lon, obs.elev = '33:45:10', '-84:23:37', 320.0
        obs.date = '1997/2/15'

        # Avoid seeing the deprecation warning for old attributes.
        warnings.filterwarnings('ignore', '.', DeprecationWarning)
Exemple #10
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def get_next_setting(location: ephem.Observer,
                     sun: ephem._sun,
                     transit_datetime: Datetime,
                     use_center: bool = False) -> Optional[Datetime]:
    try:
        d = ephem.localtime(location.next_setting(
            sun, use_center=use_center)).astimezone(tz=None)
        return remove_odd(transit_datetime, d)
    except (ephem.NeverUpError, ephem.AlwaysUpError):
        return None
Exemple #11
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def init_groundstation():
    # Ground station stuff
    gs_lat = 39.50417
    gs_lon = -80.218615
    gs_el_meters = 359.664
    gs_tzname = 'US/Eastern'
    groundstation_name = 'Fairmont'
    gs_minimum_elevation_angle = 10.0
    gs_observer = Observer()
    gs_observer.lat = gs_lat * math.pi / 180.0
    gs_observer.lon = gs_lon * math.pi / 180.0
    gs_observer.elevation = gs_el_meters

    # Times we need
    now = datetime.now()
    tomorrow = now + timedelta(1)
    gs_observer.date = now
    #now += timedelta(hours=14) # testing
    #tomorrow = now + timedelta(hours=4) # testing
    gs_tz = timezone(gs_tzname)
    gs_start = gs_tz.localize(now)
    gs_end = gs_tz.localize(tomorrow)
    #print(gs_start)
    #print(gs_end)

    gs = GroundStation.from_location(gs_lat, gs_lon, \
                                     gs_el_meters, \
                                     gs_tzname, \
                                     groundstation_name, \
                                     gs_minimum_elevation_angle)

    return [gs, gs_observer, gs_tz, gs_start, gs_end]
    def _isVisible(self, coord, startTime, duration):
        """
        For a given source and datetime, check if the source is visible
        during the specified duration. Not that the horizon here is
        the elevation specified by the user. Note that the coordinate of
        source is specified as 'RA;Dec'
        """
        endTime = startTime + datetime.timedelta(hours=duration)
        time = startTime
        while time < endTime:
            lofar = Observer()
            lofar.lon = '6.869882'
            lofar.lat = '52.915129'
            lofar.elevation = 15.
            lofar.date = time

            target = FixedBody()
            target._epoch = '2000'
            coordTarget = SkyCoord('{} {}'.format(coord.split(';')[0], \
                              coord.split(';')[1]), \
                              unit=(u.hourangle, u.deg))
            target._ra = coordTarget.ra.radian
            target._dec = coordTarget.dec.radian
            target.compute(lofar)
            targetElevation = float(target.alt) * 180. / np.pi

            if targetElevation < self.elevation:
                return False

            time += datetime.timedelta(minutes=15)
        # Turns out this source is above the horizon
        return True
    def findCalibrator(self, time):
        """
        For a given datetime, return a list of calibrators that are above
        the minimum elevation limit.
        """
        # Create the telescope object
        # The following values were taken from otool.py which is part of the
        # LOFAR source visibility calculator.
        lofar = Observer()
        lofar.lon = '6.869882'
        lofar.lat = '52.915129'
        lofar.elevation = 15.*u.m
        lofar.date = time
        
        # Create the target object
        target = FixedBody()
        target._epoch = '2000'
        target._ra = self.coordPoint1.ra.radian
        target._dec = self.coordPoint1.dec.radian
        target.compute(lofar)
        targetElevation = float(target.alt)*180./np.pi

        # Create the calibrator object
        calibrator = FixedBody()
        calibrator._epoch = '2000'
        calName = []
        distance = []
        for item in self.validCals:
            myCoord = getCalPointing(item)
            calibrator._ra = myCoord.split(';')[0]
            calibrator._dec = myCoord.split(';')[1]
            calibrator.compute(lofar)
            tempElevation = float(calibrator.alt)*180./np.pi
            if tempElevation > self.elevation:
                calName.append(item)
                distance.append(np.absolute(tempElevation-targetElevation))
        return calName[np.argmin(distance)]
	def solve_coordinates(self, satellites, lines1, lines2):

		from ephem import Observer, degrees, now
		self.observer = Observer()
		(lon, lat, ele) = self.get_location()

		self.observer.lon = degrees(lon)
		self.observer.lat = degrees(lat)
		self.observer.elevation = ele

		self.observer.date = now()
		self.observer.epoch = now()
		
		for i in range(self.index):
			self.pyephem_routine(satellites[i], lines1[i], lines2[i])
Exemple #15
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    def solve_coordinates(self, index):

        self.observer = Observer()
        (lon, lat, ele) = self.get_location()

        self.observer.lon = degrees(lon)
        self.observer.lat = degrees(lat)
        self.observer.elevation = ele

        self.observer.date = now()
        self.observer.epoch = now()

        for i in range(index):
            self.pyephem_routine(self.show_satellite_list[i],
                                 self.tle_first_line_list[i],
                                 self.tle_second_line_list[i])
    def __build_obs (self) :
        '''Set up the Observer

        Returns:
            The observer built
        '''
        local_observer = Observer ()
        local_observer.pressure = 0
        local_observer.horizon  = HORIZON
        local_observer.lat = LATITUDE
        local_observer.lon = LONGITUDE
        return local_observer
Exemple #17
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def rise_and_set(lat, lon, horizon=0):
    sun = Sun()
    date = None
    while True:
        loc = Observer()
        loc.horizon = str(horizon)
        loc.lat = str(lat)
        loc.lon = str(lon)
        loc.date = clock.now()
        #if date:
        #    loc.date = date
        #loc.date = loc.date.datetime().date() # strip time
        t_rise = loc.next_rising(sun)
        t_set = loc.next_setting(sun)
        #date = yield localtime(t_rise), localtime(t_set)
        yield localtime(t_rise), localtime(t_set)
    def findHBACalibrator(self, time, exclude=None):
        """
        For a given datetime, return the ``best'' flux density calibrator
        for an HBA observation.
        """
        # Create the telescope object
        # The following values were taken from otool.py which is part of the
        # LOFAR source visibility calculator.
        lofar = Observer()
        lofar.lon = '6.869882'
        lofar.lat = '52.915129'
        lofar.elevation = 15.
        lofar.date = time

        # Create a target object
        # If multiple targets are specified, use the first one
        target = FixedBody()
        target._epoch = '2000'
        coordTarget = SkyCoord('{} {}'.format(\
                              self.targetRA[0],
                              self.targetDec[0]),
                              unit=(u.hourangle, u.deg))
        target._ra = coordTarget.ra.radian
        target._dec = coordTarget.dec.radian
        target.compute(lofar)
        targetElevation = float(target.alt) * 180. / np.pi

        # Create the calibrator object
        calibrator = FixedBody()
        calibrator._epoch = '2000'
        calName = []
        calibElevation = []
        if exclude is not None:
            self.validCalibs.remove(exclude)
        for item in self.validCalibs:
            myCoord = self._getCalPointing(item)
            calibrator._ra = myCoord.split(';')[0]
            calibrator._dec = myCoord.split(';')[1]
            calibrator.compute(lofar)
            tempElevation = float(calibrator.alt) * 180. / np.pi
            #print 'Temp is', tempElevation
            #if tempElevation > self.elevation:
            #    calName.append(item)
            #    calibElevation.append(tempElevation)
            #print calibElevation
            calName.append(item)
            calibElevation.append(tempElevation)
        if calibElevation[np.argmax(calibElevation)] < self.elevation:
            showWarningPopUp('One of the chosen calibrator is below user '+\
                'specified elevation [{} degrees].'.format(self.elevation) +\
                ' Will generate text file anyway.')
        return calName[np.argmax(calibElevation)]
Exemple #19
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 def test_pressure_at_11km(self):
     o = Observer()
     o.elevation = 11e3
     o.compute_pressure()
     assert 226.31 < o.pressure < 226.33
Exemple #20
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 def test_pressure_at_sea_level(self):
     o = Observer()
     o.elevation = 0
     o.compute_pressure()
     self.assertEqual(o.pressure, 1013.25)
Exemple #21
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def main():
    # arguments
    from argparse import ArgumentParser
    args = ArgumentParser(
        epilog=
        """This script will compute the local coordinates (altitude and azimuth) for Jupiter
and Saturn for the given date. Altitude is degrees above the horizon and azimuth is degrees eastwards from North. Locate North
by finding the Polaris, the pole star.""")
    args.add_argument(
        "-x",
        "--longitude",
        type=float,
        default=-74.151494,
        help=
        "East longitude of the observer in decimal degrees. West is negative.")
    args.add_argument(
        "-y",
        "--latitude",
        type=float,
        default=40.373545,
        help="North latitude of the observer. South is negative.")
    args.add_argument("-t",
                      "--timezone",
                      type=str,
                      default='US/Eastern',
                      help="The local time-zone of the observer.")
    args.add_argument("-e",
                      "--elevation",
                      type=float,
                      default=20e0,
                      help="Elevation in metres above sea level.")
    args.add_argument(
        "time",
        nargs='?',
        default=datetime.now().strftime("%H:%M:%S"),
        help="Local time for calculation, default is current time, as HH:MM:SS."
    )
    args.add_argument(
        "date",
        nargs='?',
        default=datetime.now().strftime("%Y-%m-%d"),
        help=
        "Local date for calculation, default is current date, as YYYY-MM-DD.")
    args = args.parse_args()

    # time
    localtime = timezone(args.timezone)
    utc = timezone('UTC')
    timestamp = localtime.localize(
        datetime.strptime(args.date + ' ' + args.time, '%Y-%m-%d %H:%M:%S'))
    observer = Observer()
    observer.lat = args.latitude * pi / 180.0
    observer.lon = args.longitude * pi / 180.0
    observer.date = timestamp.astimezone(utc)
    observer.elevation = args.elevation

    print(
        "Calculation of the location of Jupiter and Saturn for an observer at %.4f° %s, %.4f° %s, %.4f m above sea level.\n"
        % (abs(args.longitude), "E" if args.longitude > 0 else "W",
           abs(args.latitude), "N" if args.latitude > 0 else "S",
           args.elevation))

    print("Computed for local time %s." %
          timestamp.astimezone(localtime).strftime('%Y-%m-%d %H:%M:%S'))

    # Sun
    sun = Sun(observer)
    sunlight = max(0e0, cos(pi / 2 - sun.alt)) * 1e2

    if sunlight > 0:
        print(
            "The Sun is currently above the horizon, with light at %.2f %%, at %.2f° %s."
            % (sunlight, (sun.az - pi if sun.az > pi else sun.az) * 180e0 / pi,
               "E" if sun.az < pi else "W" if sun.az > pi else "S"))

        sunset = utc.localize(
            datetime.strptime(str(
                observer.next_setting(sun)), "%Y/%m/%d %H:%M:%S")).astimezone(
                    localtime) if observer.next_setting(sun) != None else None

        if sunset != None:
            print("The Sun will set at %s." % sunset.strftime("%H:%M:%S"))

    else:
        print("The Sun has set.")

        sunrise = utc.localize(
            datetime.strptime(str(
                observer.next_rising(sun)), "%Y/%m/%d %H:%M:%S")).astimezone(
                    localtime) if observer.next_rising(sun) != None else None
        print("The Sun will rise at %s." % sunrise.strftime("%H:%M:%S"))

    # Moon
    moon = Moon(observer)
    moonlight = max(0e0, cos(pi / 2 - moon.alt)) * 1e2

    if moonlight > 0:
        print(
            "The Moon is currently above the horizon, with light at %.2f %%." %
            moonlight)

    # Jupiter
    jupiter = Jupiter(observer)

    if jupiter.alt > 0e0:
        print(
            "Jupiter is %.2f° above the horizon, %.2f° %s." %
            (jupiter.alt * 180e0 / pi,
             (2 * pi - jupiter.az if jupiter.az > pi else jupiter.az) * 180e0 /
             pi, "W" if jupiter.az > pi else "E" if jupiter.az < pi else "S"))

    else:
        print("Jupiter is not above the horizon.")

    # Jupiter
    saturn = Saturn(observer)

    if saturn.alt > 0e0:
        print("Saturn is %.2f° above the horizon, %.2f° %s." %
              (saturn.alt * 180e0 / pi,
               (2 * pi - saturn.az if saturn.az > pi else saturn.az) * 180e0 /
               pi, "W" if saturn.az > pi else "E" if saturn.az < pi else "S"))

    else:
        print("Saturn is not above the horizon.")

    # done
    print("Done.")
Exemple #22
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 def test_optimization_day_calculation_simple(self, observer: Observer,
                                              moon: Moon):
     observer.date = datetime(2017, 4, 3, 23)
     for i in range(10000):
         moon.compute(observer)
         assert moon.get_day()['number'] == 7, (moon.get_day()['number'], 7)
Exemple #23
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 def test_moon_day_calculation_simple(self, observer: Observer, moon: Moon,
                                      dt, number):
     observer.date = dt
     moon.compute(observer)
     assert moon.get_day()['number'] == number, (moon.get_day()['number'],
                                                 number)
Exemple #24
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# print data.dtypes
# print int(data['time'][0])
# print(data['time'])

# plt.figure(figsize=(14,10))
# #plt.scatter(data['t2'],data['mag'])
# n, bins, patches = plt.hist(data['t2'], bins=96)
# plt.xlim(-12,12)
# plt.show()

dt = '2016/5/27 00:00'
sun = Sun()
sun.compute(dt)

elginfield = Observer()
elginfield.lat = 43.19237
elginfield.lon = -81.31799
elginfield.date = dt
ra, dec = elginfield.radec_of('0', '-90')

print('RA_sun:',sun.ra)
print('Elgin nadir', ra)
print('Solar time:', hours((ra-sun.ra)%(2*pi)), 'hours')

fig, ax = plt.subplots(figsize=(14,10))
n, bins, patches = ax.hist(data['t2'], bins=192, rwidth=0.9, edgecolor='black')
ax.axvline(0, color='red')

plt.xlim(-12,12)
Exemple #25
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def get_lv_lofar_object():
    """Return an ephem.Observer() object with details containing the LV station"""
    lv = Observer()
    lv.lon = '21.854916'
    lv.lat = '57.553493'
    return lv
Exemple #26
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def get_ie_lofar_object():
    """Return an ephem.Observer() object with details containing the IE station"""
    ie = Observer()
    ie.lon = '-7.921790'
    ie.lat = '53.094967'
    return ie
Exemple #27
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 def test_lon_can_also_be_called_long(self):
     o = Observer()
     o.lon = 3.0
     self.assertEqual(o.long, 3.0)
     o.long = 6.0
     self.assertEqual(o.lon, 6.0)
Exemple #28
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 def test_lon_can_also_be_called_long(self):
     o = Observer()
     o.lon = 3.0
     self.assertEqual(o.long, 3.0)
     o.long = 6.0
     self.assertEqual(o.lon, 6.0)
Exemple #29
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 def test_pressure_at_11km(self):
     o = Observer()
     o.elevation = 11e3
     o.compute_pressure()
     assert 226.31 < o.pressure < 226.33
        'DATE-OBS', 'FREQCENT', 'FINECHAN', 'INTTIME', 'BANDWDTH', 'AZIMUTH',
        'ALTITUDE'
]:
    test_avail(key)

initial_date = f[0].header['DATE-OBS']
##Change in to oskar date format
date, time = initial_date.split('T')
year, month, day = date.split('-')
oskar_date = "%s-%s-%s %s" % (day, month, year, time)

time_int = float(options.time_int)
low_freq = float(options.low_freq)

##ephem Observer class, use this to compute LST from the date of the obs
MRO = Observer()
##Set the observer at Boolardy
MRO.lat, MRO.long, MRO.elevation = '-26:42:11.95', '116:40:14.93', 0
date, time = initial_date.split('T')
MRO.date = '/'.join(date.split('-')) + ' ' + time
intial_lst = float(MRO.sidereal_time()) * R2D
initial_ra_point = float(f[0].header['RA'])
dec_point = float(f[0].header['DEC'])

healpix = options.healpix
telescope_dir = options.telescope
telescope_name = options.telescope.split('/')[-1]
#template_uvfits = fits.open("%s/template_%s.uvfits" %(telescope_dir,telescope_name))
#template_data = template_uvfits[0].data
#template_baselines = template_uvfits[0].data['BASELINE'].copy()
#num_baselines = len(template_data)
Exemple #31
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 def setUp(self):
     self.tunhien = Observer()
     self.tunhien.lon, self.tunhien.lat = '105.83416', '21.027764'
     self.timezone = 7
     self.solardate = date(1991, 10, 24)
Exemple #32
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 def test_pressure_at_sea_level(self):
     o = Observer()
     o.elevation = 0
     o.compute_pressure()
     self.assertEqual(o.pressure, 1013.25)
Exemple #33
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from ephem import Equatorial
from ephem import Galactic
import datetime

# set the default azimuth and elevation for the  first calcuation
az = '220'
el = '20'
el = '45'

nargs = len(sys.argv)
el = float(sys.argv[1])

print 'Calculating galactic coordinates for elevation ' + str(el) + ' deg'

# first define the observer location
me = Observer()
me.lon = '-79.8397'
me.lat = '38.4331'
me.elevation = 800  # height in meters
# reformat the time into ephemerus format.
now = datetime.datetime.utcnow()
strnow = now.isoformat()
dates = strnow.split('T')
datestr = dates[0] + ' ' + dates[1]
me.date = datestr
timestrfull = str(dates[1])
times = timestrfull.split('.')
outname = dates[0] + '_' + times[0] + '.txt'
#print(outname)
# check the LST as a test
#print('UTC = ' + datestr + ' -> ' + str(me.sidereal_time()) + ' LST ')
Exemple #34
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 def test_longitude_constructor_does_not_hang(self):  # GitHub #207
     observer = Observer()
     observer.lon = '-113.78401934344532'
Exemple #35
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def whats_up(
        start: datetime.datetime,
        end: datetime.datetime,
        location: ephem.Observer,
        magnitude: float = 6.) -> dict:
    """
    Find all objects that will be "up" between start and end time.

    Takes a location, start and end time, and limiting magnitude.
    """
    body_list = []
    start_e, end_e = ephem.Date(start), ephem.Date(end)
    location.date = start_e
    for o,body_type in filter(lambda x: x[1] != 'planetary_moon', OBJECT_DICT.values()):
        o.compute(location)
        circumpolar = False
        rising, setting = None, None
        if body_type != 'satellite':
            try:
                rising = location.next_rising(o, start = location.previous_antitransit(o))
                setting = location.next_setting(o, start = rising)
            except ephem.AlwaysUpError:
                circumpolar = True
            except ephem.NeverUpError:
                pass
        elif body_type == 'satellite':
            info = list(location.next_pass(o))
            rising, setting = info[0], info[4]
        # the logic here is as follows:
        # 1. Is object bright enough?
        # 2. Is it in the sky now?
        #    a. Is it circumpolar (does it never set)?
        #    b. Does it rise during the given timeframe?
        #    c. Does it set during the given timeframe?
        #    d. Does it rise before the given timeframe and set after the given timeframe?
        if o.mag < -30:
            # something's wrong with the data--skip it.
            continue
        if o.mag < magnitude and (circumpolar or \
                                  (rising and start_e < rising < end_e) or \
                                  (setting and start_e < setting < end_e) or \
                                  (rising and setting and (rising < start_e) and \
                                      (setting > end_e))):
            # If it's in the sky and bright enough, add the entry to the list
            if rising or setting or circumpolar:
                body_list.append({
                    'name': o.name.split('|') if o.name.find('|') >= 0 else o.name,
                    'magnitude': o.mag
                })
            # If it has a rise time, add that to the most recently added item
            if rising:
                body_list[-1]['rise_time'] = rising.datetime()
            # If it has a set time, add that to the most recently added item
            if setting:
                body_list[-1]['set_time'] = setting.datetime()
            if o.name == 'Moon':
                body_list[-1]['phase'] = o.moon_phase * 100
    body_list.sort(key = lambda x: x['magnitude'])
    return {
        'start_time': start, # start of timeframe
        'end_time': end, # end of timeframe
        'objects': body_list # all items visible during timeframe, as computed above
    }