Meteosat image beacon on QO-100

  • Hello, this is my first time posting in this forum so hopefully a thread like this isn't too unsuitable.

    I've been wondering about this for a while now - would it be possible to try and reach out to Eumetsat and establish a low rate Meteosat data service over the QO-100 wideband transponder? When I say low rate I really mean something like 333 or 250 ksps, even QPSK would be enough to fit a decent amount of imagery at full resolution, but given the transmit power of the WB transponder and the low bandwidth of such beacon, 8PSK or 16APSK would probably work too to either fit even more data/FEC or reduce the bandwidth.

    The new Meteosat-12 weather satellite is commissioning currently, and I think this would be a really good way to "bring HRIT back to Europe" with very little effort needed from the ground segment. The data from this satellite (and already operating satellites) would be distributed via Eumetcast in DVB-S from Eutelsat 10B, but this requires a relatively expensive receiver set up that's out of reach of most amateurs and enthusiasts, as it also carries a ton of additional data, resulting in a massive data rate and computer requirements.

    A station like this could only be set up at Bochum for example, with just a small subset of data extracted and re-transmitted again using QO-100, this time at a relatively low rate so even a dirt cheap RTL-SDR setup with a small dish and generic LNB would be able to receive it. An arrangement like this would make it possible to set up amateur receivers of Meteosat imagery even cheaper, easier, and more robust than the current notorious GOES HRIT L-band. Eumetcast even carries GOES imagery, so that could be included in the data stream too, possibly even with Himawari.

    I tried doing some calculations for the amount of data, and a QPSK 3/4 beacon would only have to be around 375ksps to carry literally all image data from all bands at full resolution from all three currently operational Meteosat satellites (based on sizes of lossless compressed .nat files distributed by Eumetsat). A more conservative setup where only two spacecraft are used (0 degree and Indian Ocean full disk service) at a rate of 1 image per 30 minutes would only require around 100ksps. Even with GOES and Himawari included it could fit within 250ksps. Meteosat-12 will probably increase that data rate by quite a bit, but in that case only a few select channels could be transmitted, such as RGB, near and SW infrared, and one thermal infrared band, instead of all 16.

    This could technically be set up completely without the involvement of Eumetsat (besides getting the free Eumetcast key unit from them), but I believe reaching out to them about a proposition like this (if it makes any sense) would be best, as they could provide guidance on how to set up something like this. If this low rate stream was made compatible with existing Eumetcast DVB-S2 services, then even the already existing amateur and professional software alike could be compatible.

    I realize this proposition may sound too drastic, especially the fact that it would use up some of the wideband transponder space, but it can be infinitely scaled down... In the end even an hourly SSTV transmission on the NB beacon with the latest Meteosat image would make many people I know happy

  • Hello OK9SGC and welcome to the board!

    Technically possible, but as far as I know it's not legal to retransmit any transmission from Eumetcast.

    Even if for individuals (non-commercial use) the license is free, you still need the personalized USB key and they exactly want to know who is receiving it? We can try to contact Eumetsat to check what's possible..

    73 Peter

  • Thank you for the welcome.

    I figured there could be legal/regulatory issues like this. I guess it all depends on the possible openness from Eumetsat's side, whether or not they would be interested in essentially re-establishing the LRIT/HRIT service but using QO-100 as a substitute satellite, and if they would be able to make a licensing exception. Otherwise the licensing page does state that a license is not needed for data older than 3 hours, only prohibiting redistribution of "Original Numerical Data", so something simple like applying compression or reducing the color depth from 10 to 8-bit may be enough. With compression I firmly believe that even a minimal 33ksps stream would be enough to fit decent quality images without really disturbing the WB transponder traffic.

    Or alternatively just going analog and transmitting in fax/SSTV form in the newly established broadcast portion of the NB transponder like GB2RS would probably be transformative enough for the data to be exempt from licensing (the resolution and quality would be severely reduced).

    Obviously in any case a statement or guidance from Eumetsat would be required.

    I would also like to point out that full resolution images from Meteosat are accessible simply through the Internet, so the theoretical uplink station wouldn't really even need an Eumetcast receiver, and could just use an Eumetsat API to access these periodically.