FGFS-4.1/gr-air-modes
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Fields eliminated, type includes field data. Subfields also gone.

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This commit is contained in:
Nick Foster 2012-06-26 09:46:21 -07:00
parent 6a76ec8250
commit 067556cbdd
1 changed files with 57 additions and 96 deletions
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153
python/modes_parse.py
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@ -31,26 +31,20 @@ class data_field:
def __init__(self, data): def __init__(self, data):
self.data = data self.data = data
fields = { }
types = { } types = { }
subfields = { } #fields to return objects instead of just returning bits,
#used for fields which may have multiple meanings (like ME for Type 17)
offset = 1 #field offset applied to all fields. used for offsetting offset = 1 #field offset applied to all fields. used for offsetting
#subtypes to reconcile with the spec. Really just for readability. #subtypes to reconcile with the spec. Really just for readability.
#get a particular field from the data #get a particular field from the data
def __getitem__(self, fieldname): def __getitem__(self, fieldname):
if self.get_type() in self.types: mytype = self.get_type()
if fieldname in self.types[self.get_type()]: #verify it exists in this packet type if mytype in self.types:
if fieldname in self.subfields: if fieldname in self.types[mytype]: #verify it exists in this packet type
#create a new subfield object and return it return self.get_bits(*self.types[mytype][fieldname])
return self.subfields[fieldname](self.get_bits(self.fields[fieldname]))
else:
return self.get_bits(self.fields[fieldname])
else: else:
raise FieldNotInPacket(fieldname) raise FieldNotInPacket(fieldname)
else: else:
raise NoHandlerError(self.get_type()) raise NoHandlerError(mytype)
#grab all the fields in the packet as a dict #grab all the fields in the packet as a dict
def get_fields(self): def get_fields(self):
@ -65,11 +59,18 @@ class data_field:
#retrieve bits from data given the offset and number of bits. #retrieve bits from data given the offset and number of bits.
#the offset is both left-justified (LSB) and starts at 1, to #the offset is both left-justified (LSB) and starts at 1, to
#correspond to the Mode S spec. Blame them. #correspond to the Mode S spec. Blame them.
def get_bits(self, arg): def get_bits(self, *args):
(startbit, num) = arg startbit = args[0]
return (self.data \ num = args[1]
bits = (self.data \
>> (self.get_numbits() - startbit - num + self.offset)) \ >> (self.get_numbits() - startbit - num + self.offset)) \
& ((1 << num) - 1) & ((1 << num) - 1)
if len(args) == 3:
#construct a subtype from the bit field
return args[2](bits)
else:
#return the bits as a number
return bits
#type MB (extended squitter types 20,21) subfields #type MB (extended squitter types 20,21) subfields
class mb_reply(data_field): class mb_reply(data_field):
@ -100,29 +101,24 @@ class mb_reply(data_field):
return 56 return 56
class bds09_reply(data_field): class bds09_reply(data_field):
fields = {
"sub": (6,3), "dew": (10,1), "vew": (11,11), "dns": (22,1),
"vns": (23,11), "str": (34,1), "tr": (35,6), "dvr": (41,1),
"vr": (42,9), "icf": (9,1), "ifr": (10,1), "nuc": (11,3),
"gdew": (14,1), "gvew": (15,10), "gdns": (25,1), "gvns": (26,10),
"vrsrc": (36,1), "gdvr": (37,1), "gvr": (38,9), "ghds": (49,1),
"ghd": (50,6), "mhs": (14,1), "hdg": (15,10), "ast": (25,1),
"spd": (26,10)
}
offset = 6 offset = 6
types = { types = {
#BDS0,9 subtype 0 #BDS0,9 subtype 0
0: ["sub", "dew", "vew", "dns", "vns", "str", "tr", "dvr", "vr"], 0: {"sub": (6,3), "dew": (10,1), "vew": (11,11), "dns": (22,1),
"vns": (23,11), "str": (34,1), "tr": (35,6), "dvr": (41,1),
"vr": (42,9)},
#BDS0,9 subtypes 1-2 (differ only in velocity encoding) #BDS0,9 subtypes 1-2 (differ only in velocity encoding)
1: ["sub", "icf", "ifr", "nuc", "gdew", "gvew", "gdns", "gvns", "vrsrc", "gdvr", "gvr", "ghds", "ghd"], 1: {"sub": (6,3), "icf": (9,1), "ifr": (10,1), "nuc": (11,3),
"dew": (14,1), "vew": (15,10), "dns": (25,1), "vns": (26,10),
"vrsrc": (36,1), "dvr": (37,1), "vr": (38,9), "dhd": (49,1), "hd": (50,6)},
#BDS0,9 subtype 3-4 (airspeed and heading) #BDS0,9 subtype 3-4 (airspeed and heading)
3: ["sub", "icf", "ifr", "nuc", "mhs", "hdg", "ast", "spd", "vrs", "gsvr", "gvr", "ghds", "ghd"] 3: {"sub": (6,3), "icf": (9,1), "ifr": (10,1), "nuc": (11,3), "mhs": (14,1),
"hdg": (15,10), "ast": (25,1), "spd": (26,10), "vrsrc": (36,1),
"dvr": (37,1), "vr": (38,9), "dhd": (49,1), "hd": (50,6)}
} }
def get_type(self): def get_type(self):
sub = self.get_bits(self.fields["sub"]) sub = self.get_bits(6,3)
if sub == 0: if sub == 0:
return 0 return 0
if 1 <= sub <= 2: if 1 <= sub <= 2:
@ -135,38 +131,23 @@ class bds09_reply(data_field):
#type 17 extended squitter data #type 17 extended squitter data
class me_reply(data_field): class me_reply(data_field):
#TODO: add comments explaining these fields
fields = { "ftc": (1,5),
#BDS0,5 and BDS0,6 position information fields
"ss": (6,2), "saf": (8,1), "alt": (9, 12),
"time": (21,1), "cpr": (22,1), "lat": (23, 17), "lon": (40, 17),
"mvt": (6,7), "gts": (13,1), "gtk": (14,7), "trs": (1,2),
"ats": (3,1), "cat": (6,3), "ident": (9,48),
#subclassed BDS0,9 velocity information subfields
"bds09": (6,51),
#emergency type BDS6,1
"eps": (9,3)
#TODO: TCP, TCP+1/BDS 6,2/FTC 29
}
subfields = { "bds09": bds09_reply }
#types in this format are listed by BDS register #types in this format are listed by BDS register
types = { 0x05: ["ftc", "ss", "saf", "alt", "time", "cpr", "lat", "lon"], #airborne position #TODO: add comments explaining these fields
0x06: ["ftc", "mvt", "gts", "gtk", "time", "cpr", "lat", "lon"], #surface position types = { 0x05: {"ftc": (1,5), "ss": (6,2), "saf": (8,1), "alt": (9,12), "time": (21,1), "cpr": (22,1), "lat": (23,17), "lon": (40,17)}, #airborne position
0x07: ["ftc",], #TODO extended squitter status 0x06: {"ftc": (1,5), "mvt": (6,7), "gts": (13,1), "gtk": (14,7), "time": (21,1), "cpr": (22,1), "lat": (23,17), "lon": (40,17)}, #surface position
0x08: ["ftc", "cat", "ident"], #extended squitter identification and type 0x07: {"ftc": (1,5),}, #TODO extended squitter status
0x09: ["ftc", "bds09"], 0x08: {"ftc": (1,5), "cat": (6,3), "ident": (9,48)}, #extended squitter identification and type
0x09: {"ftc": (1,5), "bds09": (6,51, bds09_reply)},
#0x0A: data link capability report #0x0A: data link capability report
#0x17: common usage capability report #0x17: common usage capability report
#0x18-0x1F: Mode S specific services capability report #0x18-0x1F: Mode S specific services capability report
#0x20: aircraft identification #0x20: aircraft identification
0x61: ["ftc", "eps"] 0x61: {"ftc": (1,5), "eps": (9,3)}
} }
#maps ftc to BDS register #maps ftc to BDS register
def get_type(self): def get_type(self):
ftc = self.get_bits(self.fields["ftc"]) ftc = self.get_bits(1,5)
if 1 <= ftc <= 4: if 1 <= ftc <= 4:
return 0x08 return 0x08
elif 5 <= ftc <= 8: elif 5 <= ftc <= 8:
@ -182,30 +163,18 @@ class me_reply(data_field):
return 56 return 56
class modes_reply(data_field): class modes_reply(data_field):
#bitfield definitions according to Mode S spec #bitfield definitions according to Mode S spec for each packet type
#(start bit, num bits) types = { 0: {"df": (1,5), "vs": (6,1), "cc": (7,1), "sl": (9,3), "ri": (14,4), "ac": (20,13), "ap": (33,24)},
fields = { "df": (1,5), "vs": (6,1), "fs": (6,3), "cc": (7,1), 4: {"df": (1,5), "fs": (6,3), "dr": (9,5), "um": (14,6), "ac": (20,13), "ap": (33,24)},
"sl": (9,3), "ri": (14,4), "ac": (20,13), "dr": (9,5), 5: {"df": (1,5), "fs": (6,3), "dr": (9,5), "um": (14,6), "id": (20,13), "ap": (33,24)},
"um": (14,6), "id": (20,13), "ca": (6,3), "aa": (9,24), 11: {"df": (1,5), "ca": (6,3), "aa": (9,24), "pi": (33,24)},
"mv": (33,56), "me": (33,56), "mb": (33,56), "ke": (6,1), 16: {"df": (1,5), "vs": (6,1), "sl": (9,3), "ri": (14,4), "ac": (20,13), "mv": (33,56), "ap": (88,24)},
"nd": (7,4), "md": (11,80), "ap": (33,24), "pi": (33,24), 17: {"df": (1,5), "ca": (6,3), "aa": (9,24), "me": (33,56, me_reply), "pi": (88,24)},
"lap": (88,24), "lpi": (88,24) 20: {"df": (1,5), "fs": (6,3), "dr": (9,24), "um": (14,6), "ac": (20,13), "mb": (33,56, mb_reply), "ap": (88,24)},
} 21: {"df": (1,5), "fs": (6,3), "dr": (9,24), "um": (14,6), "id": (20,13), "mb": (33,56, mb_reply), "ap": (88,24)},
24: {"df": (1,5), "ke": (6,1), "nd": (7,4), "md": (11,80), "ap": (88,24)}
#fields in each packet type (DF value)
types = { 0: ["df", "vs", "cc", "sl", "ri", "ac", "ap"],
4: ["df", "fs", "dr", "um", "ac", "ap"],
5: ["df", "fs", "dr", "um", "id", "ap"],
11: ["df", "ca", "aa", "pi"],
16: ["df", "vs", "sl", "ri", "ac", "mv", "lap"],
17: ["df", "ca", "aa", "me", "lpi"],
20: ["df", "fs", "dr", "um", "ac", "mb", "lap"],
21: ["df", "fs", "dr", "um", "id", "mb", "lap"],
24: ["df", "ke", "nd", "md", "lap"]
} }
subfields = { "mb": mb_reply, "me": me_reply } #TODO MV
def is_long(self): def is_long(self):
return self.data > (1 << 56) return self.data > (1 << 56)
@ -213,9 +182,7 @@ class modes_reply(data_field):
return 112 if self.is_long() else 56 return 112 if self.is_long() else 56
def get_type(self): def get_type(self):
return self.get_bits(self.fields["df"]) return self.get_bits(1,5)
#TODO overload getitem to handle special parity fields
# #type MV (extended squitter type 16) subfields # #type MV (extended squitter type 16) subfields
# mv_fields = { "ara": (41,14), "mte": (60,1), "rac": (55,4), "rat": (59,1), # mv_fields = { "ara": (41,14), "mte": (60,1), "rac": (55,4), "rat": (59,1),
@ -321,32 +288,26 @@ class modes_parse:
return [velocity, heading, vert_spd, turn_rate] return [velocity, heading, vert_spd, turn_rate]
def parseBDS09_1(self, data): def parseBDS09_1(self, data):
#1: ["sub", "icf", "ifr", "nuc", "gdew", "gvew", "gdns", "gvns", "vrs", "gsvr", "gvr", "ghds", "ghd"], #1: ["sub", "icf", "ifr", "nuc", "dew", "vew", "dns", "vns", "vrsrc", "dvr", "vr", "dhd", "hd"],
bdsobj = data["me"]["bds09"] bdsobj = data["me"]["bds09"]
alt_geo_diff = bdsobj["ghd"] alt_geo_diff = bdsobj["hd"] * 25
above_below = bool(bdsobj["ghds"]) above_below = bool(bdsobj["dhd"])
if above_below: if above_below:
alt_geo_diff = 0 - alt_geo_diff; alt_geo_diff = 0 - alt_geo_diff;
vert_spd = float(bdsobj["gvr"] - 1) vert_spd = float(bdsobj["vr"] - 1) * 64
ud = bool(bdsobj["gdvr"]) ud = bool(bdsobj["dvr"])
if ud: if ud:
vert_spd = 0 - vert_spd vert_spd = 0 - vert_spd
vert_src = bool((longdata >> 20) & 1) vert_src = bool(bdsobj["vrsrc"])
ns_vel = float((longdata >> 21) & 0x3FF - 1) ns_vel = float(bdsobj["vns"])
ns = bool((longdata >> 31) & 1) ns = bool(bdsobj["dns"])
ew_vel = float((longdata >> 32) & 0x3FF - 1) ew_vel = float(bdsobj["vew"])
ew = bool((longdata >> 42) & 1) ew = bool(bdsobj["dew"])
subtype = (longdata >> 48) & 0x07 subtype = bdsobj["sub"]
if subtype == 0x02: if subtype == 0x02:
ns_vel *= 4 ns_vel <<= 2
ew_vel *= 4 ew_vel <<= 2
vert_spd *= 64
alt_geo_diff *= 25
velocity = math.hypot(ns_vel, ew_vel) velocity = math.hypot(ns_vel, ew_vel)
if ew: if ew:
ew_vel = 0 - ew_vel ew_vel = 0 - ew_vel