FGFS-4.1/gr-air-modes
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Various fixes for stability.

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This commit is contained in:
Nick Foster
2010-10-24 19:00:10 -07:00
parent a2aad97f5b
commit 4b3a225f7b
4 changed files with 35 additions and 31 deletions
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32
src/python/cpr.py
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@@ -27,13 +27,13 @@ import math, time
#this implements CPR position decoding.
latz = 15
nbits = 17
my_lat = 37.76225 #update these later!
my_lon = -122.44254
#ER
#my_lat = 37.40889176297184
#my_lon = -122.07765340805054
def nbits(surface):
return 17
# if surface == 1:
# return 19
# else:
# return 17
def nz(ctype):
return 4 * latz - ctype
@@ -69,7 +69,7 @@ def dlon(declat_in, ctype, surface):
def decode_lat(enclat, ctype, my_lat, surface):
tmp1 = dlat(ctype, surface)
tmp2 = float(enclat) / (2**nbits)
tmp2 = float(enclat) / (2**nbits(surface))
j = math.floor(my_lat/tmp1) + math.floor(0.5 + (mod(my_lat, tmp1) / tmp1) - tmp2)
# print "dlat gives " + "%.6f " % tmp1 + "with j = " + "%.6f " % j + " and tmp2 = " + "%.6f" % tmp2 + " given enclat " + "%x" % enclat
@@ -77,7 +77,7 @@ def decode_lat(enclat, ctype, my_lat, surface):
def decode_lon(declat, enclon, ctype, my_lon, surface):
tmp1 = dlon(declat, ctype, surface)
tmp2 = float(enclon) / (2.0**nbits)
tmp2 = float(enclon) / (2.0**nbits(surface))
m = math.floor(my_lon / tmp1) + math.floor(0.5 + (mod(my_lon, tmp1) / tmp1) - tmp2)
# print "dlon gives " + "%.6f " % tmp1 + "with m = " + "%.6f " % m + " and tmp2 = " + "%.6f" % tmp2 + " given enclon " + "%x" % enclon
@@ -94,8 +94,6 @@ def cpr_resolve_local(my_location, encoded_location, ctype, surface):
[my_lat, my_lon] = my_location
[enclat, enclon] = encoded_location
decoded_lat = decode_lat(enclat, ctype, my_lat, surface)
decoded_lon = decode_lon(decoded_lat, enclon, ctype, my_lon, surface)
@@ -113,12 +111,12 @@ def cpr_resolve_global(evenpos, oddpos, mostrecent, surface): #ok this is consid
#print "Even position: %x, %x\nOdd position: %x, %x" % (evenpos[0], evenpos[1], oddpos[0], oddpos[1],)
j = math.floor(((59*evenpos[0] - 60*oddpos[0])/2**nbits) + 0.5) #latitude index
j = math.floor(((59*evenpos[0] - 60*oddpos[0])/2**nbits(surface)) + 0.5) #latitude index
#print "Latitude index: %i" % j #should be 6, getting 5?
rlateven = dlateven * (mod(j, 60)+evenpos[0]/2**nbits)
rlatodd = dlatodd * (mod(j, 59)+ oddpos[0]/2**nbits)
rlateven = dlateven * (mod(j, 60)+evenpos[0]/2**nbits(surface))
rlatodd = dlatodd * (mod(j, 59)+ oddpos[0]/2**nbits(surface))
#print "Rlateven: %f\nRlatodd: %f" % (rlateven, rlatodd,)
@@ -140,7 +138,7 @@ def cpr_resolve_global(evenpos, oddpos, mostrecent, surface): #ok this is consid
#print "ni is %i" % ni
m = math.floor(((evenpos[1]*(nlthing-1)-oddpos[1]*(nlthing))/2**nbits)+0.5) #longitude index, THIS LINE IS CORRECT
m = math.floor(((evenpos[1]*(nlthing-1)-oddpos[1]*(nlthing))/2**nbits(surface))+0.5) #longitude index, THIS LINE IS CORRECT
#print "m is %f" % m #should be -16
@@ -149,7 +147,7 @@ def cpr_resolve_global(evenpos, oddpos, mostrecent, surface): #ok this is consid
else:
enclon = oddpos[1]
rlon = dl * (mod(ni+m, ni)+enclon/2**nbits)
rlon = dl * (mod(ni+m, ni)+enclon/2**nbits(surface))
if rlon > 180:
rlon = rlon - 360.0
@@ -210,7 +208,7 @@ def cpr_decode(my_location, icao24, encoded_lat, encoded_lon, cpr_format, evenli
#print "debug: icao %x not found. attempting local decode." % icao24
[local_lat, local_lon] = cpr_resolve_local(my_location, [encoded_lat, encoded_lon], cpr_format, surface) #try local decoding
# print "debug: local resolve gives %.6f, %.6f" % (local_lat, local_lon)
[rnge, bearing] = range_bearing([my_lat, my_lon], [local_lat, local_lon])
[rnge, bearing] = range_bearing(my_location, [local_lat, local_lon])
if rnge < validrange: #if the local decoding can be guaranteed valid
#print "debug: range < 180nm, position valid."
lkplist[icao24] = [local_lat, local_lon, time.time()] #update the local position for next time
@@ -233,7 +231,7 @@ def cpr_decode(my_location, icao24, encoded_lat, encoded_lon, cpr_format, evenli
#print "settled on position: %.6f, %.6f" % (decoded_lat, decoded_lon,)
if decoded_lat is not None:
[rnge, bearing] = range_bearing([my_lat, my_lon], [decoded_lat, decoded_lon])
[rnge, bearing] = range_bearing(my_location, [decoded_lat, decoded_lon])
else:
rnge = None
bearing = None