Can a message be BDS44 and BDS45 at the same time?

[ElSabio97]

Hi @junzis !!

It has been a long time hehe. I am giving a friend a helping hand trying to plot a map of temperatures.

We are using the BDS44 and BDS45 capabilities you have coded for pyModeS. We first download a chunk of data using traffic and then filter out the BDS44/45 messages. Like this:

import pyModeS as pms
from traffic.data import opensky, eurofirs
import pandas as pd

dia = pd.to_datetime("2021-09-20 12:00") #Fecha y hora de comienzo del vuelo.
delta = 5 #Duración en horas (solo valen números enteros).

frontera = eurofirs['LSAS']

vuelo = opensky.history( #Saca datos ADSB.
    (dia).strftime('%Y-%m-%d %H:%M:%S')[0:19],
    (dia + pd.Timedelta(minutes=delta)).strftime('%Y-%m-%d %H:%M:%S')[0:19],
    bounds=frontera
)

df = opensky.extended(
    (dia).strftime('%Y-%m-%d %H:%M:%S')[0:19],
    (dia + pd.Timedelta(minutes=delta)).strftime('%Y-%m-%d %H:%M:%S')[0:19],
    bounds=frontera
)

df.data['BDS'] = df.data['rawmsg'].apply(lambda x: pms.bds.infer(x, True))

df.data = df.data[(df.data.BDS.str.contains('BDS44')) | (df.data.BDS.str.contains('BDS45'))]

df.data['BDS44'] = df.data['rawmsg'].apply(lambda x: pms.bds.bds44.is44(x))
df.data['BDS45'] = df.data['rawmsg'].apply(lambda x: pms.bds.bds45.is45(x))

The thing here is that we have found a message that is infered as both BDS44 and BDS45. That is cool, but when we pass is44 and is45, both come out as true.

If you do not want to run that code, this is the message: a000133800000030ac0000e35b83

Have a nice day!

[junzis]

Hi @ElSabio97, unfortunately, in this case, there is no way to tell whether this is BDS 44 or 45.

Nevertheless, BDS 45 messages are much rarer than BDS 44 messages.

[ElSabio97]

How would you try to discard this case (s)?

Should I just not consider them?

[junzis]

Yes, that's what I would do in most cases.