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#!/usr/bin/env python
import ephem
import time
import os
from MmdDb import Db
from MmdLocation import Location
def createJavaArray (point_list, name):
astring = '''var {0} = new Array (\n'''.format (name)
astring = '{0}\tnew Array ('.format (astring)
last = 'west'
for point in point_list:
if point[0][0] == '-':
if last == 'east':
astring = astring[:-1]
astring = '{0}\n\t\t),\n\tnew Array ('.format (astring)
last = 'west'
else:
last = 'east'
astring = '{0}\n\t\tnew OpenLayers.LonLat ({1}, {2}).transform (from, to),'.format (astring, point[0], point[1])
if astring[-1] == ',':
astring = astring[:-1]
astring = '{0}\n\t\t)\n\t);'.format (astring)
return astring
def dms2degdec (lonlat):
'''
convert a position argument from Deg:Min:Sec.Frac to
Deg.Frac and round the result to 5 decimal points
'''
parts = lonlat.split (':')
if len (parts) != 3:
return 0.0
degrees = float (parts[0])
fraction = (float (parts[1]) * 60.0 + float (parts[2])) / 3600
if parts[0][0] == '-':
return round (degrees - fraction, 5)
return round (degrees + fraction, 5)
class Satellite:
def __init__ (self, location = False):
self.name = 'RADIOSCAF-B/ARISSAT-1'
self.tle_filename = '/usr/local/mmd/tles/current'
self.db = Db ()
self.initSatellite (location)
def getCurrentSSP (self):
ssp = self._loadCurrentSSP ()
return ssp['timestamp'], ssp['longitude'], ssp['latitude']
def getTrajectoryAsJavaArray (self, name, minutes = 180):
astring = '''var {0} = new Array (\n'''.format (name)
astring = '{0}\tnew Array ('.format (astring)
last = 'west'
for row in self._loadTrajectory (minutes):
if str (row['longitude'])[0] == '-':
if last == 'east':
astring = astring[:-1]
astring = '{0}\n\t\t),\n\tnew Array ('.format (astring)
last = 'west'
else:
last = 'east'
astring = '{0}\n\t\tnew OpenLayers.LonLat ({1}, {2}).transform (from, to),'.format (
astring, row['longitude'], row['latitude'])
if astring[-1] == ',':
astring = astring[:-1]
astring = '{0}\n\t\t)\n\t);'.format (astring)
return astring
def _loadTrajectory (self, minutes):
return self.db.satelliteLoadTrajectory (time.strftime ('%s'), minutes)
def _loadCurrentSSP (self):
return self.db.satelliteLoadCurrentSSP (time.strftime ('%s'))
def initSatellite (self, location = False):
if not self._loadTLE ():
return False
if location:
loc = location
else:
loc = Location ()
sat = ephem.readtle (self._tle[0], self._tle[1], self._tle[2])
obs = ephem.Observer ()
obs.long, obs.lat, obs.elevation = loc.longitude, loc.latitude, loc.altitude
sat.compute (obs)
self.longitude = dms2degdec (sat.sublong.__str__ ())
self.latitude = dms2degdec (sat.sublat.__str__ ())
self.altitude = round (float (sat.elevation.__str__ ()), 1)
def computeTrajectory (self):
'''
computes 5 hours of future trajectory data, starting at the
latest timestamp found in data base
'''
sat = ephem.readtle (self._tle[0], self._tle[1], self._tle[2])
graz = ephem.Observer ()
graz.long, graz.lat, graz.elevation = 15.44226, 47.06576, 376
latest = self.db.satelliteGetLatestSSP ()
if latest:
timestamp = int (latest['timestamp']) + 60
else:
timestamp = int (time.strftime ('%s')) + 60
while timestamp % 60 != 0:
timestamp += 1
for i in range (60 * 5):
graz.date = time.strftime ('%Y/%m/%d %H:%M:%S', time.gmtime (timestamp))
sat.compute (graz)
self.db.satelliteInsertNewSSP (timestamp, dms2degdec (sat.sublong.__str__ ()), dms2degdec (sat.sublat.__str__ ()))
timestamp += 60
return True
def _loadTLE (self):
try:
tle = open (self.tle_filename, 'r')
except IOError:
return False
self._tle = []
count = 0
for line in tle.readlines ():
self._tle.append (line)
count += 1
if count != 3:
return False
return True
if __name__ == "__main__":
satellite = Satellite ()
minutes = 30
try:
assert satellite._loadTLE (), 'loading TLE failed'
print satellite._tle
assert satellite.computeTrajectory (), 'computing trajectory failed'
trajectory = satellite.getTrajectoryAsJavaArray ('curves', minutes)
assert trajectory, 'got not trajectory'
print trajectory
t, lon, lat = satellite.getCurrentSSP ()
assert t, 'loading current SSP failed'
print lon, lat, time.strftime ('%c', time.gmtime (t))
print satellite.longitude, satellite.latitude, satellite.altitude
except AssertionError as e:
print 'Error: {0}'.format (e)
# vim: tw=0 ts=2
# EOF
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