Observation 3841994: NOAA 9 (15427)

Regarding Observation 3841994
Seems like an unmodulated carrier only

Hi @glidermike and welcome to the community!
Exactly, this is what we call a zombie satellite, in this category we have satellites that have completed their mission or they had issues. So, we don’t expect anything useful from it.

thanks for the info Fredy

According to applicable international law, these satellites should be passivated - meaning in particular that all transmitters or other radiating sources should be switched-off and disabled - also for unintentional switching-on, e.g. during periods with sunlight exposure.

OSCAR reports:

Space agency [NOAA]

Status Inactive
Details on Status
(as available)
Launch 12 Dec 1984 EOL 13 Feb 1998
Last update: 2015-07-28

There is a guy looking-out for recordings on reddit:

Gepostet von:

Looking for NOAA-9 recordings

He identified the following potential frequencies, where signals could possibly appear:

"So far, the following frequencies have been identified, but note that they may vary slightly due to the nature of the satellite:

136.77 MHz (either APT or DSB carrier shifted down, 850 kHz or 1000 kHz respectively)

1707 MHz (HRPT carrier)

There are also other frequencies worth investigating, since the satellite originally used them, has hardware that can transmit on them, or are interesting for some other reason (note that the signal to expect is just a carrier, no matter the original mode):

136.62 MHz (APT shifted down 1000 kHz)

136.92 MHz (DSB shifted down 850 kHz)

137.5 MHz (mentioned on Wikipedia, no source given, possible backup APT)

137.62 MHz (original APT)

137.77 MHz (original DSB)

466 MHz (DCP)

2247.5 MHz (CDA)"

!37.770 is maybe a hit…
You might want to share your observations with him?


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