flightaware/beast-splitter

decimal form and CPR

Opened this issue · 12 comments

After planting, beast packets provide coordinates in both decimal form and CPR. At the beginning of taxiing, the coordinates are only visible in the CPR. Because of this, the "VRS" and FR24 do not show the aircraft
"VRS" shows the aircraft only after take-off from the ground. when he lands, shows the full path with taxiing to the terminal. "FR24" during take-off also switches to another receiver.
BEAST v2.40

I don't understand what you mean. beast-splitter forwards the raw packets unchanged; there is no "decimal form"? (More generally, beast-format packets are just the raw data, no position decoding is done at that point, it's entirely up to what receives them e.g. VRS)

I would guess that the lack of positions in VRS is because VRS does not know your receiver location.

Surface positions are globally ambiguous, to decode them you need to know an approximate location of the aircraft (it can be very approximate).

Usually you'd use the receiver location to do this. You can also use a recent airborne position. But when an aircraft is first seen, on the ground, with no previous position and no receiver location, the surface position is ambiguous. This is probably why you do not see positions before takeoff, but do see positions after landing.

(regardless, none of this is a beast-splitter problem, beast-splitter just forwards the raw data)

landing data
*8c4b844c39dc8585b69b749940db;
CRC: 000000
RSSI: -11.7 dBFS
Time: 4397372325777.25us
DF:17 AA:4B844C CA:4 ME:39DC8585B69B74
Extended Squitter Surface position (7)
ICAO Address: 4B844C (Mode S / ADS-B)
Air/Ground: ground
Heading: 202
Speed: 11 kt groundspeed
CPR type: Surface
CPR odd flag: odd
CPR NUCp/NIC: 7
CPR latitude: 47.86868 (49883)
CPR longitude: 35.31604 (39796)
CPR decoding: global
takeoff data
*8c4baaaa381933a87d61511fc0cb;
CRC: 000000
RSSI: -16.8 dBFS
Time: 4485324665402.92us
DF:17 AA:4BAAAA CA:4 ME:381933A87D6151
Extended Squitter Surface position (7)
ICAO Address: 4BAAAA (Mode S / ADS-B)
Air/Ground: ground
Heading: 53
Speed: 0 kt groundspeed
CPR type: Surface
CPR odd flag: even
CPR NUCp/NIC: 7
CPR latitude: (119870)
CPR longitude: (90449)
CPR decoding: none
The aircraft before take-off are not visible in the "VRS". ФР24 also ignores and switches to another receiver.

The "decimal" values are dump1090 doing some position decoding work for you. These values are not included in the raw data. dump1090 is the same as VRS, dump1090 needs to know the receiver location or a recent airborne position to be able to do surface position decoding. See the "CPR decoding" line to see what sort of decoding dump1090 has done.

Understood thanks

Hi, how to change 12MHz to GPS
I set such parameters
ENABLED="yes"
INPUT_OPTIONS="--serial /dev/beast"
OUTPUT_OPTIONS="--listen 30005:R"
Where to put the letter G ?

yes. beast FA

ok i'm try.

Hi. Can i use for example INPUT_OPTIONS="--serial /dev/beast --net 192.168.10.50:30055" ?
Or i must use or --serial or --net ?
In short can i use the splitter as a mixer ?

Currently only a single source of data is supported