Re: [Discuss-gnuradio] DOPPLER SHIFT

[Marcus Müller]

well, kind of
I think you're confusing different things:

* Hardware: Your HackRF has the job of tuning to a center frequency, things like gain and giving you a lot of signal samples from there.
* Doppler Tracking: There's software that can calculate the doppler a signal has that comes from a satellite as it passes over you
* libHackRF: This is the software to talk to your HackRF. It has the job of setting parameters like gain and center frequency on the HackRF, and get the samples from the HackRF
* GNU Radio: A software defined radio framework that let's you use signal processing blocks. So far, we haven't talked about that at all, so I kind of wonder why you're asking us :) Not that I mind, but I think we should try to give this discussion to some distinctive direction.

So, what is it that you need to do? Maybe if you could come up with some sketch of what you want to achieve, it'll be easier to explain what you need.

Best regards,
Marcus

On 01.04.2016 21:26, ERNEST MATEY wrote:

Thank you much Marcus,

I tried reading on internet about libHackRf but no introductions. 

However, from your comment, I suggest it means I can connect HackRf to tracking software doppler using LibHackRf!

Is that it?

Best Regards

Ernest.   

Sent from my BlackBerry 10 smartphone.

From: Marcus Müller

Sent: Friday, April 1, 2016 7:49 PM

To: ERNEST MATEY; address@hidden

Subject: Re: [Discuss-gnuradio] DOPPLER SHIFT

Dear Ernest,

Haven't used that, but hamlib is something completely different than Gpredict; it's meant to control ham radio equipment, not to predict doppler shift. If I can get that right from quickly having a glimpse at hamlib, it seems like it was written for hardware that connects to (or emulates a) sound card. The HackRF isn't one of these, so you won't be able to interface it with hamlib. Why would you, too? It's bandwidth is much greater, and with gr-osmosdr, there's a very mature and well-maintained interface to GNU Radio. You'll need libhackrf.

Generally, for frequencies you can receive with something like the HackRF, a quick, rough estimate tells me that LEO satellites (which probably are what you're concerned about) won't exhibit much more than a couble kHz Doppler; you usually would not re-tune the SDR frontend to correct that, but get a bandwidth that's big enough to contain all your receive spectrum over its full Doppler shift range.

Best regards,
Marcus

On 01.04.2016 20:25, ERNEST MATEY wrote:

Hi Marcus and All 

Thank you very much for your reply

Apart from Gpredict, which other way could I use for doppler shifting for satellite tracking. 

Please what do you say about Hamlib?‎ 

Which other method can I use to control HackRF frequency from satellite tracker on GNUradio? 

Best‎ Regards

Ernest.

Sent from my BlackBerry 10 smartphone.

From: Marcus Müller

Sent: Friday, March 18, 2016 6:35 PM

To: address@hidden

Subject: Re: [Discuss-gnuradio] DOPPLER SHIFT

Hi Ernest,
I saw your first mail, too, but I was really busy at that time.

Now, what your error message indicates is that gpredict wasn't properly installed. Not having used that myself, I can't really be of much help, but you should first of all check that if you run a python2 prompt, "import gpredict" doesn't fail with the same error.

Best regards,
Marcus

On 03/18/2016 12:43 PM, ERNEST MATEY wrote:

Hi All,

I am trying to track Satellite for CW  signal receiving and analysis on my GNURadio.  

I know I need some tracking with Doppler shift. 

What is the best way to do this?

Now, I have GPredict installed hoping to use it. 

I have added the GPredict doppler block to my GRC library blocks and added the block to my flow graph hoping to get Doppler shift from my engaged GPredict 

I have set my Ports correctly but I have an error.

ImportError: No module named gpredict. 

What can I do?  

I also learnt I can control my receiver ( Hackrf) frequency dir‎ectly from Gpredict using Hamlib. Will this work?  

I tried to install Hamlib but installation says will delete some GRC files before Hamlib will work‎. I don't want to temper with my healthy running GRC 

What can I do for my Doppler Shift?

I am on Ubuntu 14 and I am very new to these thing

Thank you for sharing your expertise.

God Bless you!  

Sent from my BlackBerry 10 smartphone.

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio