Unidentified Signals 21E to 12W

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    Using ~1.5dB NF MMDS down converter with a 2 turn helical feed on a 1.5m PF dish. Feed gives RHCP, is about 4-5 degrees offset and may not be exactly at the dish focus. The LO is at ~1998.02-1998.03MHz depending on temperature.


    There are two similar signals at about 8E on 2237.5MHz and at 9W on 2242.5MHz. The one at 9W was seen with and without data on a sub-carrier. Its level varied by about 25dB through the day so it appears to be in an inclined orbit. The one at 8E seemed to have a fairly stable level +/- few dB. The 8E wide plot shows, what appears to be, a few MHz wide data signal. This peaks at the same point and at the same times of day as the carrier with sidebands signal.


    The 12E signal on 2241.0 was only seen once and may be inclined orbit satellite.


    The 21E, 2206.5MHz, signal did not vary through the day. Its exact centre frequency was 2206.51735MHz.


    The CW at 12W on 2211MHz is probably TDRS 9's beacon.

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    Did you check this list already?
    http://www.zarya.info/Frequencies/FrequenciesSband.php


    2237.5 : NRO IR-early warning satellite, at 8°E is DSP F18
    2242.5 : NRO comm's satellite, at 10°W is SDS-3 F7
    2241.0 : this probably was Astra 1H moving East, near 12°E when you checked.
    2206.5 : don't know, maybe AfriStar at 21.0°E, with 2.6° inclination. Or TianLian 1C relay satellite at 20.4°E without inclination.


    (Corrected: TianLian is relay, not weather satellite!)

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    Many thanks. I used zarya.info but I think I was looking at too many things at one time and got lost! I used your listings and links from it, zarya, uhf-satcom.com etc


    I had 2237.5 as possibly USA149, is that the same as NRO IR-early warning satellite, at 8°E is DSP F18? The wide band signal is on the right frequency according to zarya.info


    2242.5 : I wondered if this was USA227. Has that replaced USA 236 (NRO comm's satellite, at 10°W is SDS-3 F7)?


    I could not find reference to Astra1H having an S band beacon but neither could I find anything on that frequency at that location. If I had time I could try to relate it to the Ku beacon.


    For 2206.5 TianLian 1C was on my possibles list, I think that may be it. I wondered about Afristar but the signal is too stable to be inclined far.

    1.2m Prodelin 3122 az-el with one of:
    S: Helical feed, 0.8dB NF LNA, X: 1.2dB NF LNA, conical feed,
    Ku 12-18GHz: corrugated conical feed, 1.5dB NF LNA, Ku (Standard): SMW Q-PLL type C, Prodelin feed. Ku (Extended): 11.3GHz LO SMW & Prodelin Feed Ka: Gilat ex-ODU PLLs Gilat feeds, Ka 18-26.5GHz: Patriot feed, home made 4dB NF LNA, Ka DSN: Corrugated conical feed, home made 3dB NF Down-Converter

    1.5m IRTE, Polar mount with Octagon OSLO mod. C120, IRTE feed
    40km East of London, UK

    Einmal editiert, zuletzt von s-band ()

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    The Zarya list seems several years old, some satellites listed there are end-of life or relocated by now. But as you see, for example the DSP or SDS series seems to use similar frequencies.


    The USA number designation is also listed (if available) on my site. Since it's so non-descriptive, I don't use it as the main satellite name.
    https://en.wikipedia.org/wiki/List_of_USA_satellites


    If a satellite uses S-band as a "real" payload, that will be listed on my site. But I suspect many more use S-band, probably for TT&C only. That's why I suggested Astra 1H that coincidentally drifted near 12°E that you reported, probably I was wrong...

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    I went through the S-band listings on Zarya, UHF-Satcom and Satellitenwelt: http://satellitenwelt.de/satfreq_s-band.htm


    And here is another reference to several satellites, having this particular (or previous) S-band transponder on board: https://www.thalesgroup.com/si…document/isbt_ed4_eng.pdf
    Includes several Eutelsat W-series and Hot Bird satellites, do you know if these are actually active?
    As I understood from another document, these may be standby TT&C transponders, only used during launch, drift, or problems with the regular TT&C in Ku-band.


    So I had to add S-band for many satellites in my list!
    Most military satellites seem to use S-band, at least for TT&C.
    But still in doubt about the Mentor, MUOS ans SBIRS series.

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    Very interesting, hvdh, thank you. The Thales flyer refers to many more satellites than I expected. Turning the dish whilst scanning I noticed quite a lot more signals but it takes some time to confirm if they are satellite, local or other terrestrial. I'll look again when I get some time.

    1.2m Prodelin 3122 az-el with one of:
    S: Helical feed, 0.8dB NF LNA, X: 1.2dB NF LNA, conical feed,
    Ku 12-18GHz: corrugated conical feed, 1.5dB NF LNA, Ku (Standard): SMW Q-PLL type C, Prodelin feed. Ku (Extended): 11.3GHz LO SMW & Prodelin Feed Ka: Gilat ex-ODU PLLs Gilat feeds, Ka 18-26.5GHz: Patriot feed, home made 4dB NF LNA, Ka DSN: Corrugated conical feed, home made 3dB NF Down-Converter

    1.5m IRTE, Polar mount with Octagon OSLO mod. C120, IRTE feed
    40km East of London, UK

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    Zitat

    Original von s-band
    For 2206.5 TianLian 1C was on my possibles list, I think that may be it. I wondered about Afristar but the signal is too stable to be inclined far.


    Maybe this helps: TianLian 1C has left 20.4°E on the 1st of July, now near 13.7°E, still moving West with 1° per day.

    • Offizieller Beitrag
    Zitat

    Original von hvdh


    Maybe this helps: TianLian 1C has left 20.4°E on the 1st of July, now near 13.7°E, still moving West with 1° per day.


    I think that you have got it. It has moved from the original position. The postioner is not very accurate but it is around the 12.6E where was supposed to be when I looked. It is about 2dB lower in signal but is still one of the strongest signals there. I'll look again in a few days.


    I found another at about 36E +/-3 deg on 2322.766MHz RHC. I can not see anything in the frequency lists there although there is a cluster of US satellites below 2232.5MHz. Your list has Sircal 2 and Athena-Fidus in that region.

    Bilder

    1.2m Prodelin 3122 az-el with one of:
    S: Helical feed, 0.8dB NF LNA, X: 1.2dB NF LNA, conical feed,
    Ku 12-18GHz: corrugated conical feed, 1.5dB NF LNA, Ku (Standard): SMW Q-PLL type C, Prodelin feed. Ku (Extended): 11.3GHz LO SMW & Prodelin Feed Ka: Gilat ex-ODU PLLs Gilat feeds, Ka 18-26.5GHz: Patriot feed, home made 4dB NF LNA, Ka DSN: Corrugated conical feed, home made 3dB NF Down-Converter

    1.5m IRTE, Polar mount with Octagon OSLO mod. C120, IRTE feed
    40km East of London, UK

    Einmal editiert, zuletzt von s-band ()

    • Offizieller Beitrag

    Thank you for the check, your reception is enough confirmation the TianLian's use the 2.2 GHz band!
    The TianLian's Ka frequencies still remain to be discovered.


    Probably 1C will stop at 10.6°E, the most westerly ITU registration for TianLian (aka CTDRS).

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    Zitat

    Original von hvdh
    Probably 1C will stop at 10.6°E, the most westerly ITU registration for TianLian (aka CTDRS).


    It's now around 10.6E after being at 10.5 last night so it looks like it is stopping there.
    http://www.n2yo.com/?s=38730

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    I found this whilst looking for Echostar 21. Echostar was in inclined orbit at the time of looking but this was stable so may be TianLian 1C. It is on a different frequency and looks different to the signal I found before.


    The actual frequency is ~2206.500MHz (LO~1997.97MHz)

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