def is50or60(msg, spd_ref, trk_ref, alt_ref):
"""Use reference ground speed and trk to determine BDS50 and DBS60.
Args:
msg (String): 28 bytes hexadecimal message string
spd_ref (float): reference speed (ADS-B ground speed), kts
trk_ref (float): reference track (ADS-B track angle), deg
alt_ref (float): reference altitude (ADS-B altitude), ft
Returns:
String or None: BDS version, or possible versions, or None if nothing matches.
"""
def vxy(v, angle):
vx = v * np.sin(np.radians(angle))
vy = v * np.cos(np.radians(angle))
return vx, vy
if not (bds50.is50(msg) and bds60.is60(msg)):
return None
h50 = bds50.trk50(msg)
v50 = bds50.gs50(msg)
if h50 is None or v50 is None:
return "BDS50,BDS60"
h60 = bds60.hdg60(msg)
m60 = bds60.mach60(msg)
i60 = bds60.ias60(msg)
if h60 is None or (m60 is None and i60 is None):
return "BDS50,BDS60"
m60 = np.nan if m60 is None else m60
i60 = np.nan if i60 is None else i60
XY5 = vxy(v50 * aero.kts, h50)
XY6m = vxy(aero.mach2tas(m60, alt_ref * aero.ft), h60)
XY6i = vxy(aero.cas2tas(i60 * aero.kts, alt_ref * aero.ft), h60)
allbds = ["BDS50", "BDS60", "BDS60"]
X = np.array([XY5, XY6m, XY6i])
Mu = np.array(vxy(spd_ref * aero.kts, trk_ref))
# compute Mahalanobis distance matrix
# Cov = [[20**2, 0], [0, 20**2]]
# mmatrix = np.sqrt(np.dot(np.dot(X-Mu, np.linalg.inv(Cov)), (X-Mu).T))
# dist = np.diag(mmatrix)
# since the covariance matrix is identity matrix,
# M-dist is same as eculidian distance
try:
dist = np.linalg.norm(X - Mu, axis=1)
BDS = allbds[np.nanargmin(dist)]
except ValueError:
return "BDS50,BDS60"
return BDS
def infer(msg):
"""Estimate the most likely BDS code of an message
Args:
msg (String): 28 bytes hexadecimal message string
Returns:
String or None: BDS version, or possible versions, or None if nothing matches.
"""
df = common.df(msg)
if common.allzeros(msg):
return 'EMPTY'
# For ADS-B / Mode-S extended squitter
if df == 17:
tc = common.typecode(msg)
if 1 <= tc <= 4:
return 'BDS08' # indentification and category
if 5 <= tc <= 8:
return 'BDS06' # surface movement
if 9 <= tc <= 18:
return 'BDS05' # airborne position, baro-alt
if tc == 19:
return 'BDS09' # airborne velocity
if 20 <= tc <= 22:
return 'BDS05' # airborne position, gnss-alt
if tc == 28:
return 'BDS61' # aircraft status
if tc == 29:
return 'BDS62' # target state and status
if tc == 31:
return 'BDS65' # operational status
# For Comm-B replies, ELS + EHS only
IS10 = bds10.is10(msg)
IS17 = bds17.is17(msg)
IS20 = bds20.is20(msg)
IS30 = bds30.is30(msg)
IS40 = bds40.is40(msg)
IS50 = bds50.is50(msg)
IS60 = bds60.is60(msg)
allbds = np.array(
["BDS10", "BDS17", "BDS20", "BDS30", "BDS40", "BDS50", "BDS60"])
mask = [IS10, IS17, IS20, IS30, IS40, IS50, IS60]
bds = ','.join(sorted(allbds[mask]))
if len(bds) == 0:
return None
else:
return bds
def infer(msg, mrar=False):
"""Estimate the most likely BDS code of an message.
Args:
msg (str): 28 hexdigits string
mrar (bool): Also infer MRAR (BDS 44) and MHR (BDS 45). Defaults to False.
Returns:
String or None: BDS version, or possible versions, or None if nothing matches.
"""
df = common.df(msg)
if common.allzeros(msg):
return "EMPTY"
# For ADS-B / Mode-S extended squitter
if df == 17:
tc = common.typecode(msg)
if 1 <= tc <= 4:
return "BDS08" # identification and category
if 5 <= tc <= 8:
return "BDS06" # surface movement
if 9 <= tc <= 18:
return "BDS05" # airborne position, baro-alt
if tc == 19:
return "BDS09" # airborne velocity
if 20 <= tc <= 22:
return "BDS05" # airborne position, gnss-alt
if tc == 28:
return "BDS61" # aircraft status
if tc == 29:
return "BDS62" # target state and status
if tc == 31:
return "BDS65" # operational status
# For Comm-B replies
IS10 = bds10.is10(msg)
IS17 = bds17.is17(msg)
IS20 = bds20.is20(msg)
IS30 = bds30.is30(msg)
IS40 = bds40.is40(msg)
IS50 = bds50.is50(msg)
IS60 = bds60.is60(msg)
IS44 = bds44.is44(msg)
IS45 = bds45.is45(msg)
if mrar:
allbds = np.array([
"BDS10",
"BDS17",
"BDS20",
"BDS30",
"BDS40",
"BDS44",
"BDS45",
"BDS50",
"BDS60",
])
mask = [IS10, IS17, IS20, IS30, IS40, IS44, IS45, IS50, IS60]
else:
allbds = np.array(
["BDS10", "BDS17", "BDS20", "BDS30", "BDS40", "BDS50", "BDS60"])
mask = [IS10, IS17, IS20, IS30, IS40, IS50, IS60]
bds = ",".join(sorted(allbds[mask]))
if len(bds) == 0:
return None
else:
return bds