def satpass(tmin, tmax):
def nextpass(u):
# Update target for rise/set calculations by updating tle
rise, fall = 0, -1
while rise>fall:
self.obs.date = ephem.Date(u) # Set obs. date
target = ephem.readtle('TLE0',*tle.mount(u).split(',')) # Set appropriate TLE
passdata = self.obs.next_pass(target) # Compute passdata
print passdata
rise, fall = float(passdata[0]), float(passdata[4])
print passdata[2], passdata[3]
u = tm(u).eph()-ephem.minute
return rise, fall # Return rise/set times
passes = [] # Create container
umin, umax = tm(tmin).eph(), tm(tmax).eph() # Convert to Julian dates
for sat in self.sats.values():
tle = TLE_config(sat, tmax) # Mount TLE database file
rise, fall = nextpass(umin) # Find first pass
while rise<umax:
passes.append(Pass(sat,tm(rise),tm(fall),tle.now)) # Add pass info
rise, fall = nextpass(fall+5*ephem.second) # Find next pass
return passes
def printout1(self, tmin, tmax, show, passfile):
#Print satellite pass search bounds
if show:
if passfile:
print 'Retrieving satellite passes from file (truncated at bounds)...'
else:
print 'Calculating satellite passes (truncated at bounds)...'
print 'From: %.1f -> %s\nTo: %.1f -> %s\n'%(tm(tmin).utc,tm(tmin).eph(),
tm(tmax).utc,tm(tmax).eph())
return
def passes(self, tmin, tmax, passfile=floc['Nov2015'], saveas=None, show=True):
"""Finds rise and set times of all passes falling within bounds
Note: next_pass returns the following data as a tuple:
0- Rise time, 1- Rise azimuth
2- Max alt time, 3- Max alt
4- Set time, 5- Set azimuth """
def satpass(tmin, tmax):
def nextpass(u):
# Update target for rise/set calculations by updating tle
rise, fall = 0, -1
while rise>fall:
self.obs.date = ephem.Date(u) # Set obs. date
target = ephem.readtle('TLE0',*tle.mount(u).split(',')) # Set appropriate TLE
passdata = self.obs.next_pass(target) # Compute passdata
print passdata
rise, fall = float(passdata[0]), float(passdata[4])
print passdata[2], passdata[3]
u = tm(u).eph()-ephem.minute
return rise, fall # Return rise/set times
passes = [] # Create container
umin, umax = tm(tmin).eph(), tm(tmax).eph() # Convert to Julian dates
for sat in self.sats.values():
tle = TLE_config(sat, tmax) # Mount TLE database file
rise, fall = nextpass(umin) # Find first pass
while rise<umax:
passes.append(Pass(sat,tm(rise),tm(fall),tle.now)) # Add pass info
rise, fall = nextpass(fall+5*ephem.second) # Find next pass
return passes
#Either calculate data or load from previously calculated data
self.passlist = []
self.printout1(tmin,tmax,show,passfile) # Print satpass range
if passfile:
with open(passfile) as f:
for line in f:
dat = line.strip().split(';')
self.passlist.append(Pass(self.sats[dat[0]],tm(dat[1]),tm(dat[2]),dat[3]))
else:
sortkey = lambda x: (x.rise,x.fall) # Pass sorting method
self.passlist = sorted(satpass(tmin,tmax), key=sortkey) # Produce passlist
self.printout2(self.passlist, self.sats, show) # Print passes
if saveas:
with open(saveas,'w+') as f:
[f.write('%s;%.2f;%.2f;%s\n'%(p.sat.ID,tm(p.rise).utc,tm(p.fall).utc,p.TLE)) for p in passlist]
return self.passlist
def mount(self, t):
t = tm(t) # Convert to tm time
if tm(self.now, 'tle') > t: # For backtracking
self.load()
while tm(self.nxt, 'tle') <= t:
# Find last TLE before t
try:
self.now = self.nxt
self.nxt = self.data.next().strip()
except StopIteration:
break
return self.now
def printout2(self, plist, sats, show):
#Print number of passes found for each satellite
print ''
if show: # Print pass data
tabform = '%-8s%-12s%-24s%-24s'
dform = '%Y/%m/%d %H:%M:%S'
print tabform%('Pass:'******'Sat:','Rise:','Set:')
for i,p in zip(range(len(plist)),plist):
print ' '+tabform%(i+1, p.sat.desig ,tm(p.rise).cal(dform), tm(p.fall).cal(dform))
# Print pass count per satellite
nstring = ''.join([i.sat.desig for i in plist])
pcount = [(s.desig, nstring.count(s.desig)) for s in sats.values()]
print '\nPasscount: %d'%sum(i[1] for i in pcount)
for s in range(len(pcount)):
print '%s %-8s: %d '%('' if s%4 else '\n',pcount[s][0],pcount[s][1]),
print '\n' if s%4 else ''
return
def compute(u, seek=False):
# Keep constant tle for ephemeris calculation over single pass
self.obs.date = ephem.Date(u.eph())
self.target.compute(self.obs)
alt_rad=self.target.alt
alt_deg=(alt_rad/np.pi)*180.0
az_rad=self.target.az
az_deg=(az_rad/np.pi)*180.0
return [tm(self.obs.date).utc, alt_deg, az_deg]
def geteph(timestamps):
# Compute eph for single pass- operates in the form: target.compute(obs)
timestamps = [tm(float(t)) for t in timestamps]
for sat in self.sats.values():
if (sat.desig == satellite_desig):
sat_tuple=sat
tle = TLE_config(sat_tuple, t_max) # Mount TLE database file
#print "latest TLE is from %s " % (tle.lastrecord())
self.target = ephem.readtle('TLE0',*tle.mount(t_max).split(',')) # Set appropriate TLE
#self.target = ephem.readtle('TLE0',*satpass.TLE.split(','))
eph = [compute(u) for u in timestamps]
return np.swapaxes(eph,0,1)
def nextpass(u):
# Update target for rise/set calculations by updating tle
rise, fall = 0, -1
while rise>fall:
self.obs.date = ephem.Date(u) # Set obs. date
target = ephem.readtle('TLE0',*tle.mount(u).split(',')) # Set appropriate TLE
passdata = self.obs.next_pass(target) # Compute passdata
print passdata
rise, fall = float(passdata[0]), float(passdata[4])
print passdata[2], passdata[3]
u = tm(u).eph()-ephem.minute
return rise, fall # Return rise/set times
def ephemeris(self, satpass=None, timestamps=None, ephfile=None, saveas=None, quiet=True):
"""Calculates ephemeris for passes within trange using step size tstep (excluding
right bound if tmax-tmin%tstep!=0) to produce a list of numpy arrays in t,alt,azi"""
if ephfile:
data = [line.strip().split(',') for line in open(ephfile)]
return [[float(j) for j in i] for i in data]
def compute(u, seek=False):
# Keep constant tle for ephemeris calculation over single pass
self.obs.date = ephem.Date(u.eph())
self.target.compute(self.obs)
return [tm(self.obs.date).utc, self.target.alt, self.target.az]
# Compute eph for single pass- operates in the form: target.compute(obs)
timestamps = [tm(t) for t in timestamps if tm(t)>satpass.rise and tm(t)<satpass.fall]
self.target = ephem.readtle('TLE0',*satpass.TLE.split(','))
eph = [compute(u) for u in timestamps]
if saveas:
with open(saveas,'w+') as f:
[f.write('%.2f,%f,%f\n'%(e[0],e[1],e[2])) for e in eph]
#return np.swapaxes(eph,0,1)
return eph
def __init__(self, sat, tmax, uid=ST['login'], lim=None):
self.sat = sat.ID # Associate class instance to NORAD ID
print "Sat is %s" % self.sat
self.tlefile = floc[
'TLEpath'] % self.sat # Define TLE database location for sat
print "looking in %s " % self.tlefile
# Use tail to check last TLE, update if required
tmax = tm(tmax)
#print "tmax is %s" % tmax
result = read['tail'](self.tlefile)
#print "result is %s" % result
tlelast = tm(result, 'tle') if result else tm(ST['newTLE'])
#print "tlelast was %s" % tlelast
#tlelast.utc = tlelast.utc + 100000
#print "tlelast is now %s" % tlelast
#print "tm(ST['newTLE'] is %s" % tm(ST['newTLE'])
#print "tlelast is %s " % tlelast
print 'Sat %s: Checking database...\n' % self.sat,
# If required, repeatedly pull tles from SpaceTrack until all>tmax
print 'tlelast,tmax', tlelast, tmax
while tlelast < tmax:
#wait for 5 secs as you are only allowed 20 queries per minute
time.sleep(5)
dfrom, dupto = tm(tlelast - ST['safety']), tm(tlelast +
ST['chunk'])
query = ST['query'] % (self.sat, dfrom, dupto,
'limit/%d/' if lim else "")
print "Requesting update from SpaceTrack:\n\n%s\n" % query
os.system(ST['request'] %
(uid[0], uid[1], query, ST['cookies'], ST['dload']))
print 'Validating and distributing to database...',
#print ST['dload']
with open(ST['dload']) as f:
for d in f:
tlestring = '%s,%s\n' % (d.strip(), f.next().strip())
tletime = tm(tlestring, 'tle')
if tletime > tlelast:
open(self.tlefile, 'a').write(tlestring)
tlelast = tletime
if dupto > tmax:
break
tlelast = tm(tlelast + chunk)
print 'OK'
self.data = open(self.validate()) # Validate then mount database
self.load() # Load initial TLE
def compute(u, seek=False):
# Keep constant tle for ephemeris calculation over single pass
self.obs.date = ephem.Date(u.eph())
self.target.compute(self.obs)
return [tm(self.obs.date).utc, self.target.alt, self.target.az]