I’m trying to get a handle on the amount of traffic that there is on the various many ACARS channels that seem to be in use. In a previous post, I counted 20 channels and that information was from a few different sources.
So i pointed the output of acarsdec to a text file, and let it capture almost 82k messages over the 7.6 day period from 4 Jun to today. Due to the maximum instantaneous bandwidth limitations of acarsdec and the RTL-SDR dongle, I decided to focus on the following
| 130.025 | 130.425 | 130.450 | 130.825 | 131.125 | 131.425 | 131.550 |
| 71.8% | 0.0% | 0.2% | 0.0% | 0.0% | 0.0% | 27.8% |
| 49621 | 20 | 172 | 18 | 2 | 31 | 19211 |
| 4.54 | 0.00 | 0.02 | 0.00 | 0.00 | 0.00 | 1.76 |
As can be seen, the vast majority of ACARS messages on the 7 channels scanned over that 7.6 day period are on only 2 channels, 130.025 and 131.550. Row 1 is the channel frequency, row 2 the percentage of messages received on that channel, row 3 the absolute message count for that channel, and row 4 the average messages per minute on that channel.
Now I’ll change the channels and do another run to see if there is more activity elsewhere.