Token
Member
Howdy all,
I keep meaning to dive deeper into sat monitoring, but RL gets in the way and I am just not getting there. However, I do take occasional looks at various freqs that might be sat related.
Yesterday I tuned to the frequency range 400 - 406 MHz, looking for Radiosonde signals. There was a signal I did not recognize on about 401.5 MHz. It was visually similar to some Radiosonde telemetry signals, but much wider in bandwidth, about 50 kHz wide. After 10'ish minutes of observation I noticed it appeared to have (possible) Doppler shift on it, assuming it was not simple transmitter frequency drift. The frequency shift was down, as might be expected as a sat moves away.
I picked the signal up around 0118 UTC, the frequency was already slightly below 401.5 MHz. If the transmit freq was 401.5 MHz the sat was already past its closest point. The signal faded out with pretty typical Sat LOS characteristics about 0307 UTC. The receive location was slightly north of Los Angeles CA. So I observed it for about 1 hour and 20 minutes, and suspect it was already past CPA, indicating it may have been above my horizon for over 2 hours 40 minutes. At LOS the direction was probably (guessing based on antenna position, the antenna is pretty wide beamed) SSW.
Screen shot of the signal:
Audio of the signal (FM):
Smaller file (MP3) http://www.tokenradio.net/Radio/SharedFiles/SatTfer/Unk_sat_401_1_MHz_FM_24062022_0153_s.mp3
Larger file (WAV) http://www.tokenradio.net/Radio/SharedFiles/SatTfer/Unk_sat_401_1_MHz_FM_24062022_0153z.wav
Anyone have any idea if this was a sat? If so, any clue as to what sat it might have been?
Thanks,
T!
I keep meaning to dive deeper into sat monitoring, but RL gets in the way and I am just not getting there. However, I do take occasional looks at various freqs that might be sat related.
Yesterday I tuned to the frequency range 400 - 406 MHz, looking for Radiosonde signals. There was a signal I did not recognize on about 401.5 MHz. It was visually similar to some Radiosonde telemetry signals, but much wider in bandwidth, about 50 kHz wide. After 10'ish minutes of observation I noticed it appeared to have (possible) Doppler shift on it, assuming it was not simple transmitter frequency drift. The frequency shift was down, as might be expected as a sat moves away.
I picked the signal up around 0118 UTC, the frequency was already slightly below 401.5 MHz. If the transmit freq was 401.5 MHz the sat was already past its closest point. The signal faded out with pretty typical Sat LOS characteristics about 0307 UTC. The receive location was slightly north of Los Angeles CA. So I observed it for about 1 hour and 20 minutes, and suspect it was already past CPA, indicating it may have been above my horizon for over 2 hours 40 minutes. At LOS the direction was probably (guessing based on antenna position, the antenna is pretty wide beamed) SSW.
Screen shot of the signal:
Audio of the signal (FM):
Smaller file (MP3) http://www.tokenradio.net/Radio/SharedFiles/SatTfer/Unk_sat_401_1_MHz_FM_24062022_0153_s.mp3
Larger file (WAV) http://www.tokenradio.net/Radio/SharedFiles/SatTfer/Unk_sat_401_1_MHz_FM_24062022_0153z.wav
Anyone have any idea if this was a sat? If so, any clue as to what sat it might have been?
Thanks,
T!
