gr-air-modes/python/modes_parse.py
2012-06-25 17:25:57 -07:00

364 lines
12 KiB
Python

#
# Copyright 2010, 2012 Nick Foster
#
# This file is part of gr-air-modes
#
# gr-air-modes is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# gr-air-modes is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with gr-air-modes; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
import time, os, sys
from string import split, join
from altitude import decode_alt
import cpr
import math
from modes_exceptions import *
#this implements a packet class which can retrieve its own fields.
class data_field:
def __init__(self, data):
self.data = data
fields = { }
types = { }
subfields = { } #fields to return objects instead of just returning bits
startbit = 0 #field offset applied to all fields. used for offsetting subtypes to reconcile with spec.
#get a particular field from the data
def __getitem__(self, fieldname):
if self.get_type() in self.types:
if fieldname in self.types[self.get_type()]: #verify it exists in this packet type
if fieldname in self.subfields:
#create a new subfield object and return it
return self.subfields[fieldname](self.get_bits(self.fields[fieldname]))
else:
return self.get_bits(self.fields[fieldname])
else:
raise FieldNotInPacket(fieldname)
else:
raise NoHandlerError(self.get_type())
#grab all the fields in the packet as a dict
def get_fields(self):
return {field: self[field] for field in self.types[self.get_type()]}
def get_type(self):
raise NotImplementedError
def get_numbits(self):
raise NotImplementedError
#retrieve bits from data given the offset and number of bits.
#the offset is both left-justified (LSB) and starts at 1, to
#correspond to the Mode S spec. Blame them.
def get_bits(self, arg):
(offset, num) = arg
return (self.data \
>> (self.get_numbits() - offset - num + self.startbit + 1)) \
& ((1 << num) - 1)
#type MB (extended squitter types 20,21) subfields
class mb_reply(data_field):
fields = { "acs": (45,20), "ais": (41,48), "ara": (41,14), "bcs": (65,16),
"bds": (33,8), "bds1": (33,4), "bds2": (37,4), "cfs": (41,4),
"ecs": (81,8), "mte": (60,1), "rac": (55,4), "rat": (59,1),
"tid": (33,26), "tida": (63,13), "tidb": (83,6), "tidr": (76,7),
"tti": (61,2)
}
startbit = 32 #fields offset by 32 to match documentation
#types are based on bds1 subfield
types = { 0: ["bds", "bds1", "bds2"], #TODO
1: ["bds", "bds1", "bds2", "cfs", "acs", "bcs"],
2: ["bds", "bds1", "bds2", "ais"],
3: ["bds", "bds1", "bds2", "ara", "rac", "rat",
"mte", "tti", "tida", "tidr", "tidb"]
}
def get_type(self):
bds1 = self.get_bits(self.fields["bds1"])
bds2 = self.get_bits(self.fields["bds2"])
if bds1 not in (0,1,2,3) or bds2 not in (0,):
raise NoHandlerError
return int(bds1)
def get_numbits(self):
return 56
#type 17 extended squitter data
class me_reply(data_field):
#TODO: add comments explaining these fields
fields = { "ftc": (1,5), "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), "sub": (6,3),
"bds09": (9,48), "eps": (9,3)
#TODO: TCP, TCP+1/BDS 6,2
}
subfields = { "bds09": bds09_reply }
startbit = 0
#types in this format are listed by BDS register
types = { 0x05: ["ftc", "ss", "saf", "alt", "time", "cpr", "lat", "lon"], #airborne position
0x06: ["ftc", "mvt", "gts", "gtk", "time", "cpr", "lat", "lon"], #surface position
0x07: ["ftc",], #TODO extended squitter status
0x08: ["ftc", "cat", "ident"], #extended squitter identification and type
0x09: ["ftc", "sub", "bds09"],
#0x0A: data link capability report
#0x17: common usage capability report
#0x18-0x1F: Mode S specific services capability report
#0x20: aircraft identification
0x61: ["ftc", "eps"]
}
#maps ftc to BDS register
def get_type(self):
ftc = self.get_bits(self.fields["ftc"])
if 1 <= ftc <= 4:
return 0x08
elif 5 <= ftc <= 8:
return 0x06
elif 9 <= ftc <= 18:
return 0x05
elif ftc == 19:
return 0x09
else:
return NoHandlerError
def get_numbits(self):
return 56
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), "svr": (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),
"vrs": (36,1), "gsvr": (37,1), "gvr": (38,9), "ghds": (49,1),
"ghd": (50,6), "mhs": (14,1), "hdg": (15,10), "ast": (25,1),
"spd": (26,10)
}
types = { #TODO
def get_type(self):
return self.get_bits(self.fields["sub"])
class modes_reply(data_field):
#bitfield definitions according to Mode S spec
#(start bit, num bits)
fields = { "df": (1,5), "vs": (6,1), "fs": (6,3), "cc": (7,1),
"sl": (9,3), "ri": (14,4), "ac": (20,13), "dr": (9,5),
"um": (14,6), "id": (20,13), "ca": (6,3), "aa": (9,24),
"mv": (33,56), "me": (33,56), "mb": (33,56), "ke": (6,1),
"nd": (7,4), "md": (11,80), "ap": (33,24), "pi": (33,24),
"lap": (88,24), "lpi": (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):
return self.data > (1 << 56)
def get_numbits(self):
return 112 if self.is_long() else 56
def get_type(self):
return self.get_bits(self.fields["df"])
#TODO overload getitem to handle special parity fields
# #type MV (extended squitter type 16) subfields
# mv_fields = { "ara": (41,14), "mte": (60,1), "rac": (55,4), "rat": (59,1),
# "vds": (33,8), "vds1": (33,4), "vds2": (37,4)
# }
class modes_parse:
def __init__(self, mypos):
self.my_location = mypos
self.cpr = cpr.cpr_decoder(self.my_location)
def parse0(self, data):
fields = data.get_fields()
altitude = decode_alt(data["ac"], True)
return [fields["vs"], fields["cc"], fields["sl"], fields["ri"], altitude]
def parse4(self, data):
fields = data.get_fields()
altitude = decode_alt(data["ac"], True)
return [data["fs"], data["dr"], data["um"], altitude]
def parse5(self, data):
return [data["fs"], data["dr"], data["um"], data["id"]]
def parse11(self, data, ecc):
interrogator = ecc & 0x0F
return [data["aa"], interrogator, data["ca"]]
categories = [["NO INFO", "RESERVED", "RESERVED", "RESERVED", "RESERVED", "RESERVED", "RESERVED", "RESERVED"],\
["NO INFO", "SURFACE EMERGENCY VEHICLE", "SURFACE SERVICE VEHICLE", "FIXED OBSTRUCTION", "RESERVED", "RESERVED", "RESERVED"],\
["NO INFO", "GLIDER", "BALLOON/BLIMP", "PARACHUTE", "ULTRALIGHT", "RESERVED", "UAV", "SPACECRAFT"],\
["NO INFO", "LIGHT", "SMALL", "LARGE", "LARGE HIGH VORTEX", "HEAVY", "HIGH PERFORMANCE", "ROTORCRAFT"]]
def parseBDS08(self, data):
catstring = self.categories[data["me"]["ftc"]-1][data["me"]["cat"]]
msg = ""
for i in range(0, 8):
msg += self.charmap( data["me"]["ident"] >> (42-6*i) & 0x3F)
return (msg, catstring)
def charmap(self, d):
if d > 0 and d < 27:
retval = chr(ord("A")+d-1)
elif d == 32:
retval = " "
elif d > 47 and d < 58:
retval = chr(ord("0")+d-48)
else:
retval = " "
return retval
def parseBDS05(self, data):
icao24 = data["aa"]
encoded_lon = data["me"]["lon"]
encoded_lat = data["me"]["lat"]
cpr_format = data["me"]["cpr"]
altitude = decode_alt(data["me"]["alt"], False)
[decoded_lat, decoded_lon, rnge, bearing] = self.cpr.decode(icao24, encoded_lat, encoded_lon, cpr_format, 0)
return [altitude, decoded_lat, decoded_lon, rnge, bearing]
#welp turns out it looks like there's only 17 bits in the BDS0,6 ground packet after all.
def parseBDS06(self, data):
icao24 = data["aa"]
encoded_lon = data["me"]["lon"]
encoded_lat = data["me"]["lat"]
cpr_format = data["me"]["cpr"]
altitude = decode_alt(data["me"]["alt"], False)
[decoded_lat, decoded_lon, rnge, bearing] = self.cpr.decode(icao24, encoded_lat, encoded_lon, cpr_format, 1)
return [altitude, decoded_lat, decoded_lon, rnge, bearing]
def parseBDS09_0(self, shortdata, longdata):
icao24 = shortdata & 0xFFFFFF
vert_spd = ((longdata >> 6) & 0x1FF) * 32
ud = bool((longdata >> 15) & 1)
if ud:
vert_spd = 0 - vert_spd
turn_rate = (longdata >> 16) & 0x3F
turn_rate = turn_rate * 15/62
rl = bool((longdata >> 22) & 1)
if rl:
turn_rate = 0 - turn_rate
ns_vel = (longdata >> 23) & 0x7FF - 1
ns = bool((longdata >> 34) & 1)
ew_vel = (longdata >> 35) & 0x7FF - 1
ew = bool((longdata >> 46) & 1)
subtype = (longdata >> 48) & 0x07
velocity = math.hypot(ns_vel, ew_vel)
if ew:
ew_vel = 0 - ew_vel
if ns:
ns_vel = 0 - ns_vel
heading = math.atan2(ew_vel, ns_vel) * (180.0 / math.pi)
if heading < 0:
heading += 360
return [velocity, heading, vert_spd, turn_rate]
def parseBDS09_1(self, shortdata, longdata):
icao24 = shortdata & 0xFFFFFF
alt_geo_diff = longdata & 0x7F - 1
above_below = bool((longdata >> 7) & 1)
if above_below:
alt_geo_diff = 0 - alt_geo_diff;
vert_spd = float((longdata >> 10) & 0x1FF - 1)
ud = bool((longdata >> 19) & 1)
if ud:
vert_spd = 0 - vert_spd
vert_src = bool((longdata >> 20) & 1)
ns_vel = float((longdata >> 21) & 0x3FF - 1)
ns = bool((longdata >> 31) & 1)
ew_vel = float((longdata >> 32) & 0x3FF - 1)
ew = bool((longdata >> 42) & 1)
subtype = (longdata >> 48) & 0x07
if subtype == 0x02:
ns_vel *= 4
ew_vel *= 4
vert_spd *= 64
alt_geo_diff *= 25
velocity = math.hypot(ns_vel, ew_vel)
if ew:
ew_vel = 0 - ew_vel
if ns_vel == 0:
heading = 0
else:
heading = math.atan(float(ew_vel) / float(ns_vel)) * (180.0 / math.pi)
if ns:
heading = 180 - heading
if heading < 0:
heading += 360
return [velocity, heading, vert_spd]
def parse20(self, shortdata, longdata):
[fs, dr, um, alt] = self.parse4(shortdata)
#BDS defines TCAS reply type and is the first 8 bits
#BDS1 is first four, BDS2 is bits 5-8
bds1 = longdata_bits(longdata, 33, 4)
bds2 = longdata_bits(longdata, 37, 4)
#bds2 != 0 defines extended TCAS capabilities, not in spec
return [fs, dr, um, alt, bds1, bds2]
def parseMB_commB(self, longdata): #bds1, bds2 == 0
raise NoHandlerError
def parseMB_caps(self, longdata): #bds1 == 1, bds2 == 0
#cfs, acs, bcs
raise NoHandlerError
def parseMB_id(self, longdata): #bds1 == 2, bds2 == 0
msg = ""
for i in range(0, 8):
msg += self.charmap( longdata >> (42-6*i) & 0x3F)
return (msg)
def parseMB_TCASRA(self, longdata): #bds1 == 3, bds2 == 0
#ara[41-54],rac[55-58],rat[59],mte[60],tti[61-62],tida[63-75],tidr[76-82],tidb[83-88]
raise NoHandlerError