Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-31 Thread Sylvain Munaut
Hi, May I know what's the setup you used for receiving the signal? The spectrum looks very clear. * The antenna was a homemade helical antenna : http://i.imgur.com/c6JaySJ.png * It's followed by a modified LNA23 (to be centered at 1550 MHz). This is a 30 dB LNA with a 1dB NF with a built-in

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-30 Thread Cheng Chi
Hi Sylvain, May I know what's the setup you used for receiving the signal? The spectrum looks very clear. Best regards, Cheng Chi On Sat, Mar 29, 2014 at 11:39 PM, Sylvain Munaut 246...@gmail.com wrote: This is what I found for inmarsat : http://i.imgur.com/KygwHdD.jpg Some 200 kHz

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-29 Thread Sylvain Munaut
This is what I found for inmarsat : http://i.imgur.com/KygwHdD.jpg Some 200 kHz channels and some 50 kHz channels. There is also some 30 kHz channels with a small 'X' periodically in the spectrograme. Those are GMR-1 and probably leak through from Thuraya (either reflections off buildings, or

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-29 Thread Louis Brown
Did you use gr-phosphor for that plot? On Mar 29, 2014, at 10:39 AM, Sylvain Munaut 246...@gmail.com wrote: This is what I found for inmarsat : http://i.imgur.com/KygwHdD.jpg Some 200 kHz channels and some 50 kHz channels. There is also some 30 kHz channels with a small 'X'

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-29 Thread Sylvain Munaut
Did you use gr-phosphor for that plot? Of course :) -F option of osmocom_fft enables it directly. Cheers, Sylvain ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

[Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-28 Thread Cheng Chi
Hi, I am trying to receive signal from I-4 satellites of Inmarsat. I found that I-4 satellites have one global beam with 25 KHz bandwidth and several regional beams with 50 KHz bandwidth. However, I have scanned through frequency band 1525-1559 MHz and haven't been able to find those beams.

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-28 Thread Ralph A. Schmid, dk5ras
-bounces+ralph=schmid@gnu.org [mailto:discuss-gnuradio-bounces+ralph=schmid@gnu.org] On Behalf Of Cheng Chi Sent: Friday, March 28, 2014 9:41 AM To: GNURadio Discussion List Subject: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites Hi, I am trying

Re: [Discuss-gnuradio] Questions about receiving signals of Inmarsat I-4 Satellites

2014-03-28 Thread madengr
1531 MHz signals from what? If you are using a patch antenna then it probably won't have the bandwidth to cover 100 MHz. Lou KD4HSO Cheng Chi wrote - Iridium antenna (I am not able to get specific antennas for Inmarsat...Iridium is at 1616 -1626.5 MHz and Inmarsat is at 1525-1559 MHz. I