I’m thinking about putting a station in a location where internet bandwidth is pretty expensive. What is the typical monthly total internet data transferred per station?
This would be for a single UHF station with an eggbeater antenna. Assuming 100 kHz of recorded/uploaded spectrum all day every day, I think that would be less than 300 Mbytes per month of spectrum data, is my math correct? With maybe another 100 Mbytes for OS updates/etc. Does anybody have real data, maybe using vnstat or similar?
Based on some testing we have done locally you can expect a fully uploaded observation to be no more than 35MB each. Interestingly it is the sound (ogg files) in most cases that make the bulk amount of those 35MB (around 25-30MB), and frankly it is the one that is less usable and unneeded in most cases. (i.e. we should consider having a low-bandwidth option in satnogs-client to only upload Waterfall and Decoded-data, and maybe CW and FMN transmissions?). Then as @KD9KCK points out, it really depends on how many observations you will have per day. For a UHF station of almost full utilization we are seeing up to ~60 per day. That said, there is no need to utilize it to such extend and a simple note in the descirption of the GS would let the observers know that this is a bandwidth sensitive station.
For OS and updates you would not need more than 100MB per month, but this is not based on actual observed stats. I will make sure to install vnstat in one of my clients to monitor actual usage.
Lately there have been more and more requests for facilitating low-bandwidth stations. We should consider implementation of a set of features (both in client and network) to make it easier for such stations to participate.
Hey @pierros, thanks for the info about the observation file size. I didn’t realize that the sound files were uploaded, is there more documentation on this somewhere? Other than the sound files, it’s just the decoded data (AX.25 packets or similar), correct? Are the raw IQ files uploaded?
So 30 MBytes per pass works out to ~ 500 kbit/sec for a 10 min pass, this is very doable. Can you run multiple passes per station at the same time, if two sats were above the horizon?
I’m not requesting any more low-bandwidth features, I assume there’s much more important stuff to work on, haha!! I will reduce bandwidth by scheduling less observations. I’m still working out the details, but if I get permission the station will be around 68 degrees North.
IQ files are not uploaded today, if we make that a feature in the future it will likely be off by default. (opt-in) There is an option to let you save the IQ locally but you would have to grab the file quickly as it would be overwritten by the next pass.
Not really today, as the original concept was assuming an AZ-EL rotator and you’re only likely to track one thing in the sky at a given time. That said, some people run 2 clients on stationary antennas, one client for VHF and one for UHF, and those could run 2 passes at the same time… Or setup multiple rotators… a whole farm… that would be cool.
There are some changes coming to the architecture in the future that may allow for this, but today consider it one-at-a-time.
So I would safely say ~10Gb of upload per month and ~500Mb of download.
Station 21 had 450 observations over the last month (which is pretty average for our Network right now) and a utilization of ~15% of its time (which is slightly below average utilization we are seeing right now, although those stats are getting higher and higher).
