I’ve had my system connected for less than a month (19 days) and I see my ranking has drastically been shooting up. One thing I have not figured out though is what is the criteria for ranking. First, I see a column for Rank and a column for Rank Total. The two almost appear to be inverse to each other except early on, I would see ties on Rank Total but different numbers on Rank. How are these numbers derived? It would be nice to see rankings averaged by time, that way I could see approximately where I will settle in with later. I was also noticing in all the other columns drastically different numbers for people with ranking very close to each other. For example, the person ranked just above me has seen fewer ADS-B-ES aircraft and positions than I but their MLAT is four times higher than mine. Also, their “ADS-B Other Aircraft” is over double what mine is. Thinking of this “Other Aircraft”, I see that my number is quite a bit lower than others ranked near me.
As you can see, I’m mainly just puzzled about it and I’ve not seen anything to explain all the columns.
Note that the counter is one transponder ID per UTC/GMT day. When Qantas used to fly into JFK a few times a week, I would get one for the inbound flight and, if they were seen after 00:01UTC/GMT, I would also get a count for the next day(Even if the aircraft only came in three times a week).
Conversely, Helos fly up and down the Hudson all day. I could see them dozens of times and they would only count as one per UTC/GMT day.
This is actually a good thing, since ‘other’ aircraft means those without a position. It includes those mode S only aircraft which haven’t got a position via mlat, but it also includes those icao numbers which appear as a result of bogus decodes from noise. Depending on your particular receiver configuration, this number can be quite high.
If you have a well configured receiver that doesn’t produce any bogus data, and can contribute to mlat positions for the vast majority of mode S only aircraft; you can end up being penalised in the ranking compared to the guy next door to you who has a receiver that generates a lot of poorly filtered data, and therefore ‘other’ aircraft which don’t actually exist. I think piaware is more strict about filtering this out than it used to be, since you used to see sites with thousands of other planes per day which was totally unrealistic.
Personally I think that ‘other’ aircraft should not contribute to receiver ranking at all since they don’t add any positions. The ranking is largely meaningless anyway however, since what you receive is as much a function of where you are as it is how well your receiver is configured. It’s mostly useful for judging receive performance over time - if your neighbours are seeing changes in traffic at the same time you are, it’s likely not down to your receiver.
