chasemapper/chasemapper/bearings.py

281 wiersze
11 KiB
Python

#!/usr/bin/env python
#
# Project Horus - Bearing Handler
#
# Copyright (C) 2019 Mark Jessop <vk5qi@rfhead.net>
# Released under GNU GPL v3 or later
#
#
# TODO:
# [ ] Store a rolling buffer of car positions, to enable fusing of 'old' bearings with previous car positions.
#
import logging
import time
from threading import Lock
class Bearings(object):
def __init__(
self, socketio_instance=None, max_bearings=300, max_bearing_age=30 * 60
):
# Reference to the socketio instance which will be used to pass data onto web clients
self.sio = socketio_instance
self.max_bearings = max_bearings
self.max_age = max_bearing_age
# Bearing store
# Bearings are stored as a dict, with the key being the timestamp (time.time())
# when the bearing arrived in the system.
# Each record contains:
# {
# 'timestamp': time.time(), # A copy of the arrival timestamp
# 'src_timestamp': time.time(), # Optional timestamp provided by the source
# 'lat': 0.0, # Bearing start latitude
# 'lon': 0.0, # Bearing start longitude
# 'speed': 0.0, # Car speed at time of bearing arrival
# 'heading': 0.0, # Car heading at time of bearing arrival
# 'heading_valid': False, # Indicates if the car heading is considered valid (i.e. was captured while moving)
# 'raw_bearing': 0.0, # Raw bearing value
# 'true_bearing': 0.0, # Bearing converted to degrees true
# 'confidence': 0.0, # Arbitrary confidence value - TBD what ranges this will take.
# }
self.bearings = {}
self.bearing_sources = []
self.bearing_lock = Lock()
# Internal record of the chase car position, which is updated with incoming GPS data.
# If incoming bearings do not contain lat/lon information, we fuse them with this position,
# as long as it is valid.
self.current_car_position = {
"timestamp": None, # System timestamp from time.time()
"datetime": None, # Datetime object from data source.
"lat": 0.0,
"lon": 0.0,
"alt": 0.0,
"heading": 0.0,
"speed": 0.0,
"heading_valid": False,
"position_valid": False,
}
def update_car_position(self, position):
""" Accept a new car position, in the form of a dictionary produced by a GenericTrack object
(refer geometry.py). This is of the form:
_state = {
'time' : _latest_position[0], # Datetime object, with timezone info
'lat' : _latest_position[1],
'lon' : _latest_position[2],
'alt' : _latest_position[3],
'ascent_rate': self.ascent_rate, # Not used here
'is_descending': self.is_descending, # Not used here
'landing_rate': self.landing_rate, # Not used here
'heading': self.heading, # Movement heading in degrees true
'heading_valid': self.heading_valid, # Indicates if heading was calculated when the car was moving
'speed': self.speed # Speed in m/s
}
"""
# Attempt to build up new chase car position dict
try:
_car_pos = {
"timestamp": time.time(),
"datetime": position["time"],
"lat": position["lat"],
"lon": position["lon"],
"alt": position["alt"],
"heading": self.current_car_position["heading"],
"heading_valid": position["heading_valid"],
"speed": position["speed"],
"position_valid": True, # Should we be taking this from upstream somewhere?
}
# Only gate through the heading if it is valid.
if position["heading_valid"]:
_car_pos["heading"] = position["heading"]
# Mark position as invalid if we have zero lat/lon values
if (_car_pos["lat"] == 0.0) and (_car_pos["lon"] == 0.0):
_car_pos["position_valid"] = False
# Replace car position state with new data
self.current_car_position = _car_pos
except Exception as e:
logging.error("Bearing Handler - Invalid car position: %s" % str(e))
def add_bearing(self, bearing):
""" Add a bearing into the store, fusing incoming data with the latest car position as required.
bearing must be a dictionary with the following keys:
# Absolute bearings - lat/lon and true bearing provided
{'type': 'BEARING', 'bearing_type': 'absolute', 'latitude': latitude, 'longitude': longitude, 'bearing': bearing}
# Relative bearings - only relative bearing is provided.
{'type': 'BEARING', 'bearing_type': 'relative', 'bearing': bearing}
The following optional fields can be provided:
'source': An identifier for the source of the bearings, i.e. 'kerberos-sdr', 'yagi-1'
'timestamp': A timestamp of the bearing provided by the source.
'confidence': A confidence value for the bearing, from 0 to [MAX VALUE ??]
'power': A reading of signal power
'raw_bearing_angles': A list of angles, associated with...
'raw_doa': A list of TDOA result values, for each of the provided angles.
"""
# Should never be passed a non-bearing dict, but check anyway,
if bearing["type"] != "BEARING":
return
_arrival_time = time.time()
# Get a copy of the current car position, in case it is updated
_current_car_pos = self.current_car_position.copy()
if "timestamp" in bearing:
_src_timestamp = bearing["timestamp"]
else:
_src_timestamp = _arrival_time
if "confidence" in bearing:
_confidence = bearing["confidence"]
else:
_confidence = 100.0
if "power" in bearing:
_power = bearing["power"]
else:
_power = -1
if "source" in bearing:
_source = bearing["source"]
else:
_source = "unknown"
try:
if bearing["bearing_type"] == "relative":
# Relative bearing - we need to fuse this with the current car position.
# Temporary hack for KerberosSDR bearings, which are reflected across N/S
if _source == "krakensdr_doa":
bearing["bearing"] = 360.0 - bearing["bearing"]
bearing["raw_doa"] = bearing["raw_doa"][::-1]
_new_bearing = {
"timestamp": _arrival_time,
"src_timestamp": _src_timestamp,
"lat": _current_car_pos["lat"],
"lon": _current_car_pos["lon"],
"speed": _current_car_pos["speed"],
"heading": _current_car_pos["heading"],
"heading_valid": _current_car_pos["heading_valid"],
"raw_bearing": bearing["bearing"],
"true_bearing": (bearing["bearing"] + _current_car_pos["heading"])
% 360.0,
"confidence": _confidence,
"power": _power,
"source": _source,
}
# Allow override of the heading valid calculations if a hearing_override field is supplied
if "heading_override" in bearing:
_new_bearing["heading_valid"] = bearing["heading_override"]
elif bearing["bearing_type"] == "absolute":
# Absolute bearing - use the provided data as-is
_new_bearing = {
"timestamp": _arrival_time,
"src_timestamp": _src_timestamp,
"lat": bearing["latitude"],
"lon": bearing["longitude"],
"speed": 0.0,
"heading": 0.0,
"heading_valid": True,
"raw_bearing": bearing["bearing"],
"true_bearing": bearing["bearing"],
"confidence": _confidence,
"power": _power,
"source": _source,
}
else:
return
except Exception as e:
logging.error("Bearing Handler - Invalid input bearing: %s" % str(e))
return
# We now have our bearing - now we need to store it
self.bearing_lock.acquire()
self.bearings["%.4f" % _arrival_time] = _new_bearing
if _source not in self.bearing_sources:
self.bearing_sources.append(_source)
logging.info(f"Bearing Handler - New source of bearings: {_source}")
# Now we need to do a clean-up of our bearing list.
# At this point, we should always have at least 2 bearings in our store
if len(self.bearings) == 1:
self.bearing_lock.release()
return
# Keep a list of what we remove, so we can pass it on to the web clients.
_removal_list = []
# Grab the list of bearing entries, and sort them by time
_bearing_list = list(self.bearings.keys())
_bearing_list.sort()
# First remove any excess entries - we only get one bearing at a time, so we can do this simply:
if len(_bearing_list) > self.max_bearings:
self.bearings.pop(_bearing_list[0])
_removal_list.append(_bearing_list[0])
_bearing_list = _bearing_list[1:]
# Now we need to remove *old* bearings.
_min_time = time.time() - self.max_age
_curr_time = float(_bearing_list[0])
while _curr_time < _min_time:
# Current entry is older than our limit, remove it.
self.bearings.pop(_bearing_list[0])
_removal_list.append(_bearing_list[0])
_bearing_list = _bearing_list[1:]
# Advance to the next entry in the list.
_curr_time = float(_bearing_list[0])
self.bearing_lock.release()
# Add in any raw DOA data we may have been given.
if "raw_bearing_angles" in bearing:
_new_bearing["raw_bearing_angles"] = bearing["raw_bearing_angles"]
_new_bearing["raw_doa"] = bearing["raw_doa"]
# Now we need to update the web clients on what has changed.
_client_update = {
"add": _new_bearing,
"remove": _removal_list,
"server_timestamp": time.time(),
}
self.sio.emit("bearing_change", _client_update, namespace="/chasemapper")
def flush(self):
""" Clear the bearing store """
self.bearing_lock.acquire()
self.bearings = {}
self.bearing_lock.release()