Observation 4176606: SPROUT (39770)

Regarding Observation 4176606

Hi are the tangent lines say that there was an observation or if is a noise?
Shall the data be always visible as a stream centered on the waterfall?

Thanks for feedback!

Tangent lines usually mean terrestrial noise. The singal of the satellite, with the exception when the satellite hasn’t accurate TLE, like near its deployment, should be at the middle following straight line. Check this guide in the wiki that has several examples, if something is not clear let us know. :slight_smile:

By the way welcome to the community!

@fredy hello,

thank you for explanation.
I am currently testing my setup with home-brew turnstile antenna.

I get almost nothing despite the number of observations sheduled.
Well sky view at my location isn’t perfect ad nearby building is covering up view to the NE-SE.

In the ground station’s configuration I had RTL SDR gain set to 0 (defauilt setting) but then I figured that there is a guide on nose floor vs RF gain and how to best determine its value.
I came up with gain set to 29.7[dB] but it still doesn’t give me any meaningful readouts (only really weak traces on few observations - no decodable at all by GNU radio).

So I think I may test with higher gain (giving up dynamic range), or building another antenna.

BUT I was wondering (but found no information on that) if RHCP vs LHCP makes a difference and what is preferred for SatNOGS observations. I made RHCP (looking from the top of the antenna driving elements of both dipoles that are excited from coax center wires are adjacent in a way that quadrature one is located counter-clockwise - I hope I got that right that RHCP is determined by fingers showing order of dipoles excitation while thumb is showing the direction of radiation with such polarization - which is upwards in this case) version but just don’t have a way to verify if that is working as expected.

I could also go with LNA but that is cost added.

Thank you for the feedback - I am really new to sattelites :slight_smile:


I’ve seen that your latest observations are done with a higher gain… and also you managed to demodulate some frames like in this observation.

Did you changed anything else on your setup except the gain?

I’ve just rised the gain. I am experimenting with how far I can go not to rise noise floor too much.

I am also trying to select most of the observations that are on the path where my antenna actually see something because I have no clear sky in all directions.

I guess a nice feature would be (at least for testing phase) to be able to schedule observations with some predefined parametrrs in bulk. Say for next day or week.
Clicking each one by hand is tough job.