We are looking for information about active satellites transmitting in the S-band, both 2.2-2.3 and 2.40-2.45 GHz, with known modulation and coding parameters. I’ve been told that there should be plenty, yet I fail to find any detailed info.
Any help will be greatly appreciated
@kerel ^^ where is the MR?
indeed, stalled as WIP in network#347
(as well as network!642, satellitetle!10 r+, client!380)
Thanks, @KD9KCK, I appreciate the feedback. Unfortunately, we are going to need more firm information since we want to validate a rather costly ground station setup. More precisely, we need to know:
The modulation, coding, and preferably also framing parameters for the transmitter. Otherwise, we will be measuring SNR on “noise”, which is okay but not perfect. If the transmitter info in the DB says “FM”, to me it means the same as “we have no idea”.
Whether the satellite is actually active, i.e. it is transmitting on S-band at regular intervals, even if it only does so within the range of a specific ground station. I don’t think the “alive” parameter in the DB is evidence enough yet.
- 2.408 MHz
- 7-10MHz bandwidth
- Modulation QPSK NRZ-L
- SRRC 0.4 roll-off
- 10Mbit/s (w/ overhead)
- Coding RS 255,223 5x-interleaved
- CCSDS TM frames
- Idle pattern ‘DP0FLP’
- Only activated when scheduled
Thanks @INCO for information.
I suspect we’re going to find that a lot of the high data-rate S-band transmitters are only going to be on ‘on demand’ (i.e. over a controlling ground station). After all, why have it transmitting all the time if there’s no-one there to receive it?
They’re also only going to be turned on if attitude control on the platform is functional. (Why turn it on if the antenna (probably a patch) is pointing into space?)
Chicken and egg As we are growing more and have more S-Band stations ourselves, I expect that to change (pretty soon actually).
That is absolutely true.
since i’m considering to activate an s-antenna the next service i would like to know how the s-band device will be controlled. because of preamps and selective rx i will require to utilize an dedicated RTL stick or similar. i dislike the idea to craft another station and would like to see a software control. if there is already info available i would be happy to get futher info.
ps: other bands also in schedule since sevice might extended ?
Indeed, and it is also why it is difficult to find firm information about these things.
I agree; however, for the purpose of ground station testing, I stand by my recommendation to validate the mechanical and SDR parts of the setup using weather satellites on 1.7 GHz. Either that, or a drone that emulates a satellite
Can we find a feed that works with both 1.7 and 2.4 GHz ?
I’m sure it’s possible, but is it a good idea? A well-tuned antenna will act as a good first filter in front of your LNA
maybe @uhfsatcom can help?
Can’t confirm myself but Proba-V should be active.
- 2235 MHz
- 329.9 kbps
@pjm has received it in the past and may have more info.
I have the mod details somewhere, proba-v is interesting, it has a multi spectral imager ob board, apid274, apid282, apid290, apid298, imager, apid0101 adsb downlink.
There was an effort in #hearsat some time back to acquire the sband signals, and extract something usable. If I can get a down converter integrated into my system I am happy to monitor this to collect data.
@pjm, @sam210723, thanks for the info about Proba-V!