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Reorganize CPR decoder as a class to keep it simple

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Nick Foster
2012-02-01 09:14:02 -08:00
parent 105950c176
commit a43d8ee3a7
2 changed files with 68 additions and 65 deletions
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118
python/cpr.py
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@@ -154,59 +154,6 @@ def cpr_resolve_global(evenpos, oddpos, mostrecent, surface): #ok this is consid
return [rlat, rlon]
def weed_poslist(poslist):
for key, item in poslist.items():
if time.time() - item[2] > 900:
del poslist[key]
def cpr_decode(my_location, icao24, encoded_lat, encoded_lon, cpr_format, evenlist, oddlist, lkplist, surface, longdata):
#add the info to the position reports list for global decoding
if cpr_format==1:
oddlist[icao24] = [encoded_lat, encoded_lon, time.time()]
else:
evenlist[icao24] = [encoded_lat, encoded_lon, time.time()]
[decoded_lat, decoded_lon] = [None, None]
#okay, let's traverse the lists and weed out those entries that are older than 15 minutes, as they're unlikely to be useful.
weed_poslist(lkplist)
weed_poslist(evenlist)
weed_poslist(oddlist)
if surface==1:
validrange = 45
else:
validrange = 180
if icao24 in lkplist:
#do emitter-centered local decoding
[decoded_lat, decoded_lon] = cpr_resolve_local(lkplist[icao24][0:2], [encoded_lat, encoded_lon], cpr_format, surface)
lkplist[icao24] = [decoded_lat, decoded_lon, time.time()] #update the local position for next time
elif ((icao24 in evenlist) and (icao24 in oddlist) and abs(evenlist[icao24][2] - oddlist[icao24][2]) < 10):
# print "debug: valid even/odd positions, performing global decode."
newer = (oddlist[icao24][2] - evenlist[icao24][2]) > 0 #figure out which report is newer
[decoded_lat, decoded_lon] = cpr_resolve_global(evenlist[icao24][0:2], oddlist[icao24][0:2], newer, surface) #do a global decode
if decoded_lat is not None:
lkplist[icao24] = [decoded_lat, decoded_lon, time.time()]
elif my_location is not None: #if we have a location, use it
[local_lat, local_lon] = cpr_resolve_local(my_location, [encoded_lat, encoded_lon], cpr_format, surface) #try local decoding
[rnge, bearing] = range_bearing(my_location, [local_lat, local_lon])
if rnge < validrange: #if the local decoding can be guaranteed valid
lkplist[icao24] = [local_lat, local_lon, time.time()] #update the local position for next time
[decoded_lat, decoded_lon] = [local_lat, local_lon]
#print "settled on position: %.6f, %.6f" % (decoded_lat, decoded_lon,)
if decoded_lat is not None:
[rnge, bearing] = range_bearing(my_location, [decoded_lat, decoded_lon])
else:
rnge = None
bearing = None
return [decoded_lat, decoded_lon, rnge, bearing]
#calculate range and bearing between two lat/lon points
#should probably throw this in the mlat py somewhere or make another lib
@@ -237,3 +184,68 @@ def range_bearing(loc_a, loc_b):
return [rnge, bearing]
class cpr_decoder:
def __init__(self, my_location):
self.my_location = my_location
self.lkplist = []
self.evenlist = []
self.oddlist = []
def set_location(new_location):
self.my_location = new_location
def weed_poslists(self):
for poslist in [self.lkplist, self.evenlist, self.oddlist]:
for key, item in poslist.items():
if time.time() - item[2] > 900:
del poslist[key]
def decode(icao24, encoded_lat, encoded_lon, cpr_format, surface):
#def cpr_decode(my_location, icao24, encoded_lat, encoded_lon, cpr_format, evenlist, oddlist, lkplist, surface):
#add the info to the position reports list for global decoding
if cpr_format==1:
oddlist[icao24] = [encoded_lat, encoded_lon, time.time()]
else:
evenlist[icao24] = [encoded_lat, encoded_lon, time.time()]
[decoded_lat, decoded_lon] = [None, None]
#okay, let's traverse the lists and weed out those entries that are older than 15 minutes, as they're unlikely to be useful.
self.weed_poslists()
if surface==1:
validrange = 45
else:
validrange = 180
if icao24 in self.lkplist:
#do emitter-centered local decoding
[decoded_lat, decoded_lon] = cpr_resolve_local(self.lkplist[icao24][0:2], [encoded_lat, encoded_lon], cpr_format, surface)
self.lkplist[icao24] = [decoded_lat, decoded_lon, time.time()] #update the local position for next time
elif ((icao24 in self.evenlist) and (icao24 in self.oddlist) and abs(self.evenlist[icao24][2] - self.oddlist[icao24][2]) < 10):
# print "debug: valid even/odd positions, performing global decode."
newer = (self.oddlist[icao24][2] - self.evenlist[icao24][2]) > 0 #figure out which report is newer
[decoded_lat, decoded_lon] = cpr_resolve_global(self.evenlist[icao24][0:2], self.oddlist[icao24][0:2], newer, surface) #do a global decode
if decoded_lat is not None:
self.lkplist[icao24] = [decoded_lat, decoded_lon, time.time()]
elif self.my_location is not None: #if we have a location, use it
[local_lat, local_lon] = cpr_resolve_local(self.my_location, [encoded_lat, encoded_lon], cpr_format, surface) #try local decoding
[rnge, bearing] = range_bearing(self.my_location, [local_lat, local_lon])
if rnge < validrange: #if the local decoding can be guaranteed valid
self.lkplist[icao24] = [local_lat, local_lon, time.time()] #update the local position for next time
[decoded_lat, decoded_lon] = [local_lat, local_lon]
#print "settled on position: %.6f, %.6f" % (decoded_lat, decoded_lon,)
if decoded_lat is not None:
[rnge, bearing] = range_bearing(self.my_location, [decoded_lat, decoded_lon])
else:
rnge = None
bearing = None
return [decoded_lat, decoded_lon, rnge, bearing]