Regarding Observation 535926 can anyone please tell me what the signal is to the left of the waterfall that looks like a cinematic film roll?
It is the BPSK telemetry.
When in U/V Linear, the graph is centered on downlink low (check metadata and https://db.satnogs.org/satellite/39444/), which is 145.950 MHz. The BPSK telemetry (from db again) is at 145.935 MHz, that is 15kHz below, which is the frequency where you see your film roll.
So would this be considered “good” or “bad”? There is no traffic on the U/V linear, but the satellite is alive.
There are plenty of satellites out there that function just fine in some modes (CW beacon, linear transponder, digital telemetry, etc), but other other transmitters don’t work anymore. I would say that this observation is “bad” because there is no evidence of RF on the frequency being observed.
Is the satellite dead? No, because we can plainly see the telemetry. However the frequency being observed is showing no signs of activity. Again, I default to the idea of what a completely ignorant outsider would think if they saw this observation. They would see that the observation frequency is 145.950 MHz, but they would also see that there is NO evidence of a signal at that frequency? It would utterly confuse them. If there were a comment field or something to inform the casual researcher that “while no activity is seen on the U/V linear transponder at this time, the visible telemetry on the left indicates that the satellite is still transmitting in some function.” Without a clarification like that, the observation will confuse a casual observer.
Just my 2 cents.