Re: [Discuss-gnuradio] HRPT receiver
Hi Marcus, Thanks. That explains it. Will try 5 MHz with our N200. Cheers, Dan On Jun 30, 2015, at 4:56 PM, Marcus Müller wrote: Hi Daniel, that README refers to things of the past (when you specified a decimation rather than the sampling rate you want), and USRP refered to what we nowadays call the USRP1. In the version of the usrp_rx_hrpt.grc, from which the .py gets generated, the USRP source is just configured to 4MS/s. The question is whether 4MS/s is really the optimum rate; I haven't studied the HRPT signal enough to answer this. In principle, for the 100MHz devices (N210/N200), 4MS/s is a suboptimal rate, since the decimation (25) is odd, and I'd try with something less strange, like 5MS/s. Best regards, Marcus On 06/30/2015 10:49 PM, Daniel Marlow wrote: Hello, In the gnuradio/gr-noaa/README file under usrp_rx_hrpt.py, there is a comment that reads as follows: The present HRPT demodulator is only tested at decimation 16.The only other valid decimation rates are 24 and 32, which may work, but with more bit errors. No other decimation rates will work. My (perhaps naive) question is whether the important parameter is the decimation rate, or the sampling rate. For example, with 64 MHz USRP, a decimation of 16 would give 4 MHz sampling, whereas with a higher rate USRP, the same decimation would yield a higher sampling rate. I would appreciate it if someone could clarify this point for me. Sincerely, Dan Marlow ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] HRPT receiver
Hi Daniel, that README refers to things of the past (when you specified a decimation rather than the sampling rate you want), and USRP refered to what we nowadays call the USRP1. In the version of the usrp_rx_hrpt.grc, from which the .py gets generated, the USRP source is just configured to 4MS/s. The question is whether 4MS/s is really the optimum rate; I haven't studied the HRPT signal enough to answer this. In principle, for the 100MHz devices (N210/N200), 4MS/s is a suboptimal rate, since the decimation (25) is odd, and I'd try with something less strange, like 5MS/s. Best regards, Marcus On 06/30/2015 10:49 PM, Daniel Marlow wrote: Hello, In the gnuradio/gr-noaa/README file under usrp_rx_hrpt.py, there is a comment that reads as follows: The present HRPT demodulator is only tested at decimation 16.The only other valid decimation rates are 24 and 32, which may work, but with more bit errors. No other decimation rates will work. My (perhaps naive) question is whether the important parameter is the decimation rate, or the sampling rate. For example, with 64 MHz USRP, a decimation of 16 would give 4 MHz sampling, whereas with a higher rate USRP, the same decimation would yield a higher sampling rate. I would appreciate it if someone could clarify this point for me. Sincerely, Dan Marlow ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] HRPT receiver
Hi Pablo, Googling Noaa image format instantly yielded: http://commons.wikimedia.org/wiki/File:NOAA_APT_Frame_Format.gif http://www.sat.dundee.ac.uk/hrptformat.html It's already been done a few times - for example like this (really just googling GNU Radio NOAA image decode and clicking the first thing away...) http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/350-noaa-weather-satellite-reception-with-gnu-radio-and-usrp but here, Alexandru Csete used a GNU Radio-Based flowgraph just to record the received signal to a Wav file and process it via atpdec http://atpdec.sourceforge.net/ and, honestly, how cool would it be if you wrote a small piece of GNU Radio software that had a signal sink, which used the atpdec code and displayed images in a window? (Hint: awesome). So: Happy Hacking, Marcus On 02/25/2014 09:38 AM, Pablo Fernández Alonso wrote: Hello, I was wondering if someone can receive hrpt images from NOAA satellites or similar, if so, could you help me with the implementation of the receiver? There is not quite information about that format, so if you could help me I would really appreciate it. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] HRPT receiver
Hi Pablo, We are receiving 24/7 HRPT sample images http://www.poes-weather.com/sample-hrpt.html Dish: 1.5 m (parabolic) Elevation over Azimuth rotor, made in FI POES-Weather Ltd Downconverter LO 1557 MHz (or why not use DBSRX and a 1.7 GHz LNA + some filter if needed) USRP1 + TVRX (or 2) or an USB SDR dongle. GR HRPT RX software that can be found in examples. An enhanced version can be found here https://github.com/poes-weather (gr-poes-weather), it is NOT compatible with the latest GR...but should not be that tricky to update. Youtube, testing the proto-rotor http://www.youtube.com/watch?v=XYRSgOsDyrU Patrik On Tue, 2014-02-25 at 09:38 +0100, Pablo Fernández Alonso wrote: Hello, I was wondering if someone can receive hrpt images from NOAA satellites or similar, if so, could you help me with the implementation of the receiver? There is not quite information about that format, so if you could help me I would really appreciate it. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] HRPT receiver
Hi Marcus, APT is (analogue) FM BW ~35-40 kHz and HRPT BW 3 MHz digital. Using a RTLSDR to receive APT can also be found here using windows http://www.poes-weather.com/rtl-sdr/ and howto build a good antenna (RHCP) @ 137 MHz here http://www.poes-weather.com/download/jm-dca/ Patrik On Tue, 2014-02-25 at 09:58 +0100, Marcus Müller wrote: Hi Pablo, Googling Noaa image format instantly yielded: http://commons.wikimedia.org/wiki/File:NOAA_APT_Frame_Format.gif http://www.sat.dundee.ac.uk/hrptformat.html It's already been done a few times - for example like this (really just googling GNU Radio NOAA image decode and clicking the first thing away...) http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/350-noaa-weather-satellite-reception-with-gnu-radio-and-usrp but here, Alexandru Csete used a GNU Radio-Based flowgraph just to record the received signal to a Wav file and process it via atpdec http://atpdec.sourceforge.net/ and, honestly, how cool would it be if you wrote a small piece of GNU Radio software that had a signal sink, which used the atpdec code and displayed images in a window? (Hint: awesome). So: Happy Hacking, Marcus On 02/25/2014 09:38 AM, Pablo Fernández Alonso wrote: Hello, I was wondering if someone can receive hrpt images from NOAA satellites or similar, if so, could you help me with the implementation of the receiver? There is not quite information about that format, so if you could help me I would really appreciate it. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] HRPT receiver
Hi Marcus, APT is (analogue) FM BW ~35-40 kHz and HRPT BW 3 MHz digital. Using a RTLSDR to receive APT can also be found here using windows http://www.poes-weather.com/rtl-sdr/ and howto build a good antenna (RHCP) @ 137 MHz here http://www.poes-weather.com/download/jm-dca/ Patrik On Tue, 2014-02-25 at 09:58 +0100, Marcus Müller wrote: Hi Pablo, Googling Noaa image format instantly yielded: http://commons.wikimedia.org/wiki/File:NOAA_APT_Frame_Format.gif http://www.sat.dundee.ac.uk/hrptformat.html It's already been done a few times - for example like this (really just googling GNU Radio NOAA image decode and clicking the first thing away...) http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/350-noaa-weather-satellite-reception-with-gnu-radio-and-usrp but here, Alexandru Csete used a GNU Radio-Based flowgraph just to record the received signal to a Wav file and process it via atpdec http://atpdec.sourceforge.net/ and, honestly, how cool would it be if you wrote a small piece of GNU Radio software that had a signal sink, which used the atpdec code and displayed images in a window? (Hint: awesome). So: Happy Hacking, Marcus On 02/25/2014 09:38 AM, Pablo Fernández Alonso wrote: Hello, I was wondering if someone can receive hrpt images from NOAA satellites or similar, if so, could you help me with the implementation of the receiver? There is not quite information about that format, so if you could help me I would really appreciate it. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
