stratux/traffic.go

359 wiersze
8.3 KiB
Go

package main
import (
"encoding/hex"
"math"
"sync"
"time"
)
//-0b2b48fe3aef1f88621a0856110a31c01105c4e6c4e6c40a9a820300000000000000;rs=7;
/*
HDR:
MDB Type: 1
Address: 2B48FE (TIS-B track file address)
SV:
NIC: 6
Latitude: +41.4380
Longitude: -84.1056
Altitude: 2300 ft (barometric)
N/S velocity: -65 kt
E/W velocity: -98 kt
Track: 236
Speed: 117 kt
Vertical rate: 0 ft/min (from barometric altitude)
UTC coupling: no
TIS-B site ID: 1
MS:
Emitter category: No information
Callsign: unavailable
Emergency status: No emergency
UAT version: 2
SIL: 2
Transmit MSO: 38
NACp: 8
NACv: 1
NICbaro: 0
Capabilities:
Active modes:
Target track type: true heading
AUXSV:
Sec. altitude: unavailable
*/
type TrafficInfo struct {
icao_addr uint32
addr_type uint8
lat float32
lng float32
position_valid bool
alt uint32
track uint16
speed uint16
speed_valid bool
vvel int16
tail string
last_seen time.Time
}
var traffic map[uint32]TrafficInfo
var trafficMutex *sync.Mutex
func cleanupOldEntries() {
for icao_addr, ti := range traffic {
if time.Since(ti.last_seen).Seconds() > float64(60) { //FIXME: 60 seconds with no update on this address - stop displaying.
delete(traffic, icao_addr)
}
}
}
func sendTrafficUpdates() {
trafficMutex.Lock()
defer trafficMutex.Unlock()
cleanupOldEntries()
for _, ti := range traffic {
makeTrafficReport(ti)
}
}
func initTraffic() {
traffic = make(map[uint32]TrafficInfo)
trafficMutex = &sync.Mutex{}
}
func makeTrafficReport(ti TrafficInfo) {
msg := make([]byte, 28)
// See p.16.
msg[0] = 0x14 // Message type "Traffic Report".
msg[1] = 0x10 | ti.addr_type // Alert status, address type.
// ICAO Address.
msg[2] = byte((ti.icao_addr & 0x00FF0000) >> 16)
msg[3] = byte((ti.icao_addr & 0x0000FF00) >> 8)
msg[4] = byte((ti.icao_addr & 0x000000FF))
lat := float32(ti.lat)
tmp := makeLatLng(lat)
msg[5] = tmp[0] // Latitude.
msg[6] = tmp[1] // Latitude.
msg[7] = tmp[2] // Latitude.
lng := float32(ti.lng)
tmp = makeLatLng(lng)
msg[8] = tmp[0] // Longitude.
msg[9] = tmp[1] // Longitude.
msg[10] = tmp[2] // Longitude.
//Altitude: OK
//TODO: 0xFFF "invalid altitude."
alt := uint16(ti.alt)
alt = (alt + 1000) / 25
alt = alt & 0xFFF // Should fit in 12 bits.
msg[11] = byte((alt & 0xFF0) >> 4) // Altitude.
msg[12] = byte((alt & 0x00F) << 4)
msg[12] = byte(((alt & 0x00F) << 4) | 0x8) //FIXME. "Airborne".
msg[13] = 0x11 //FIXME.
// Horizontal velocity (speed).
msg[14] = byte((ti.speed & 0x0FF0) >> 4)
msg[15] = byte((ti.speed & 0x000F) << 4)
// Vertical velocity.
vvel := ti.vvel / 64 // 64fpm resolution.
msg[15] = msg[15] | byte((vvel&0x0F00)>>8)
msg[16] = byte(vvel & 0x00FF)
// Track.
trk := uint8(float32(ti.track) / TRACK_RESOLUTION) // Resolution is ~1.4 degrees.
msg[17] = byte(trk)
msg[18] = 0x01 // "light"
sendGDL90(prepareMessage(msg))
}
func parseDownlinkReport(s string) {
var ti TrafficInfo
s = s[1:]
frame := make([]byte, len(s)/2)
hex.Decode(frame, []byte(s))
// Header.
// msg_type := (uint8(frame[0]) >> 3) & 0x1f
ti.addr_type = uint8(frame[0]) & 0x07
ti.icao_addr = (uint32(frame[1]) << 16) | (uint32(frame[2]) << 8) | uint32(frame[3])
// OK.
// fmt.Printf("%d, %d, %06X\n", msg_type, ti.addr_type, ti.icao_addr)
nic := uint8(frame[11]) & 15 //TODO: Meaning?
raw_lat := (uint32(frame[4]) << 15) | (uint32(frame[5]) << 7) | (uint32(frame[6]) >> 1)
raw_lon := ((uint32(frame[6]) & 0x01) << 23) | (uint32(frame[7]) << 15) | (uint32(frame[8]) << 7) | (uint32(frame[9]) >> 1)
lat := float32(0.0)
lng := float32(0.0)
position_valid := false
if nic != 0 || raw_lat != 0 || raw_lon != 0 {
position_valid = true
lat = float32(raw_lat) * 360.0 / 16777216.0
if lat > 90 {
lat = lat - 180
}
lng = float32(raw_lon) * 360.0 / 16777216.0
if lng > 180 {
lng = lng - 360
}
}
ti.lat = lat
ti.lng = lng
ti.position_valid = position_valid
raw_alt := (uint32(frame[10]) << 4) | ((uint32(frame[11]) & 0xf0) >> 4)
// alt_geo := false // Barometric if not geometric.
alt := uint32(0)
if raw_alt != 0 {
// alt_geo = (uint8(frame[9]) & 1) != 0
alt = ((raw_alt - 1) * 25) - 1000
}
ti.alt = alt
//OK.
// fmt.Printf("%d, %t, %f, %f, %t, %d\n", nic, position_valid, lat, lng, alt_geo, alt)
airground_state := (uint8(frame[12]) >> 6) & 0x03
//OK.
// fmt.Printf("%d\n", airground_state)
ns_vel := int16(0)
ew_vel := int16(0)
track := uint16(0)
speed_valid := false
speed := uint16(0)
vvel := int16(0)
// vvel_geo := false
if airground_state == 0 || airground_state == 1 { // Subsonic. Supersonic.
// N/S velocity.
ns_vel_valid := false
ew_vel_valid := false
raw_ns := ((int16(frame[12]) & 0x1f) << 6) | ((int16(frame[13]) & 0xfc) >> 2)
if (raw_ns & 0x3ff) != 0 {
ns_vel_valid = true
ns_vel = ((raw_ns & 0x3ff) - 1)
if (raw_ns & 0x400) != 0 {
ns_vel = 0 - ns_vel
}
if airground_state == 1 { // Supersonic.
ns_vel = ns_vel * 4
}
}
// E/W velocity.
raw_ew := ((int16(frame[13]) & 0x03) << 9) | (int16(frame[14]) << 1) | ((int16(frame[15] & 0x80)) >> 7)
if (raw_ew & 0x3ff) != 0 {
ew_vel_valid = true
ew_vel = (raw_ew & 0x3ff) - 1
if (raw_ew & 0x400) != 0 {
ew_vel = 0 - ew_vel
}
if airground_state == 1 { // Supersonic
ew_vel = ew_vel * 4
}
}
if ns_vel_valid && ew_vel_valid {
if ns_vel != 0 && ew_vel != 0 {
//TODO: Track type
track = (360 + 90 - uint16(math.Atan2(float64(ns_vel), float64(ew_vel))*180/math.Pi)) % 360
}
speed_valid = true
speed = uint16(math.Sqrt(float64((ns_vel * ns_vel) + (ew_vel * ew_vel))))
}
// Vertical velocity.
raw_vvel := ((int16(frame[15]) & 0x7f) << 4) | ((int16(frame[16]) & 0xf0) >> 4)
if (raw_vvel & 0x1ff) != 0 {
// vvel_geo = (raw_vvel & 0x400) == 0
vvel = ((raw_vvel & 0x1ff) - 1) * 64
if (raw_vvel & 0x200) != 0 {
vvel = 0 - vvel
}
}
} else if airground_state == 2 { // Ground vehicle.
//TODO.
return
}
ti.track = track
ti.speed = speed
ti.vvel = vvel
ti.speed_valid = speed_valid
//OK.
// fmt.Printf("ns_vel %d, ew_vel %d, track %d, speed_valid %t, speed %d, vvel_geo %t, vvel %d\n", ns_vel, ew_vel, track, speed_valid, speed, vvel_geo, vvel)
/*
utc_coupled := false
tisb_site_id := uint8(0)
if (uint8(frame[0]) & 7) == 2 || (uint8(frame[0]) & 7) == 3 { //TODO: Meaning?
tisb_site_id = uint8(frame[16]) & 0x0f
} else {
utc_coupled = (uint8(frame[16]) & 0x08) != 0
}
*/
//OK.
// fmt.Printf("tisb_site_id %d, utc_coupled %t\n", tisb_site_id, utc_coupled)
ti.last_seen = time.Now()
trafficMutex.Lock()
traffic[ti.icao_addr] = ti
trafficMutex.Unlock()
}
//TODO
/*
// dump1090Addr = "127.0.0.1:30003"
inConn, err := net.Dial("tcp", dump1090Addr)
if err != nil {
time.Sleep(1 * time.Second)
continue
}
rdr := bufio.NewReader(inConn)
for {
buf, err := rdr.ReadString('\n')
if err != nil { // Must have disconnected?
break
}
buf = strings.Trim(buf, "\r\n")
//log.Printf("%s\n", buf)
x := strings.Split(buf, ",")
//TODO: Add more sophisticated stuff that combines heading/speed updates with the location.
if len(x) < 22 {
continue
}
icao := x[4]
icaoDec, err := strconv.ParseInt(icao, 16, 32)
if err != nil {
continue
}
mutex.Lock()
// Retrieve previous information on this ICAO code.
var pi PositionInfo
if _, ok := blips[icaoDec]; ok {
pi = blips[icaoDec]
}
if x[1] == "3" {
//MSG,3,111,11111,AC2BB7,111111,2015/07/28,03:59:12.363,2015/07/28,03:59:12.353,,5550,,,42.35847,-83.42212,,,,,,0
alt := x[11]
lat := x[14]
lng := x[15]
//log.Printf("icao=%s, icaoDec=%d, alt=%s, lat=%s, lng=%s\n", icao, icaoDec, alt, lat, lng)
pi.alt = alt
pi.lat = lat
pi.lng = lng
}
if x[1] == "4" {
// MSG,4,111,11111,A3B557,111111,2015/07/28,06:13:36.417,2015/07/28,06:13:36.398,,,414,278,,,-64,,,,,0
vel := x[12]
hdg := x[13]
vr := x[16]
//log.Printf("icao=%s, icaoDec=%d, vel=%s, hdg=%s, vr=%s\n", icao, icaoDec, vel, hdg, vr)
pi.vel = vel
pi.hdg = hdg
pi.vr = vr
}
if x[1] == "1" {
// MSG,1,,,%02X%02X%02X,,,,,,%s,,,,,,,,0,0,0,0
tail := x[10]
pi.tail = tail
}
// Update "last seen" (any type of message).
pi.last_seen = time.Now()
blips[icaoDec] = pi // Update information on this ICAO code.
mutex.Unlock()
*/