Re: [Discuss-gnuradio] intermittent pulse detection

Hi EJ, Vitt, Thanks again for the pointers... So I did as EJ suggested and implemented a FIR block that does a cross correlation with the pulse sequence. The difference does not seem massive but it does improve things a bit. The time plot is smoother and peaks seem cleaner. Some further

Re: [Discuss-gnuradio] intermittent pulse detection

Hi Dirk, in my experience SDR is a nice stuff but sometimes analog tech can help: try to lower total NF using a tuned LNA in front of you receiver... RTL dongles or other sampler are a bit deaf and noisy, and your signal seems very feeble. ... my 2 eurocent... ! Victor 2017-02-10 0:01 GMT+01:00

Re: [Discuss-gnuradio] intermittent pulse detection

Hey Dirk, Cool problem. I'll gladly help anyone tracking orangutans :) Couple direct answers here: > If the source sample rate is 1msps, and I > have decimated by 4x, say, that means I have 4x less samples coming > through per second so I should be setting 0.250msps as the sample rate > in

Re: [Discuss-gnuradio] intermittent pulse detection

Hi Marcus, Thanks again. And yes, Id be happy to do a writeup if I get things working with GnuRadio. I did a writeup of the first version I did of my project (*) and happy to do a part two of the improved version when finished (asap). Replies inline. >Well, if you have a let's say 2 kHz

Re: [Discuss-gnuradio] intermittent pulse detection

Hi Dirk, Well, if you have a let's say 2 kHz uncertainty in the frequency of your pulse, I'd really start very simple. Looking at your plots, I think we can sufficiently suppress the noise simply by low-pass filtering: * Use a Low Pass filter (real taps) with a cutoff of 1 kHz – that will let

Re: [Discuss-gnuradio] intermittent pulse detection

Hi Dan, This is something I fully do on the side (evenings, weekends) in order to help an animal rescue charity. So very much a fun / volunteering effort and I hope to build something they can use in anger. For my dayjob I work in software/robotics but radio is still very new terrain for me.

Re: [Discuss-gnuradio] intermittent pulse detection

Hey Dirk, Just curious, are you doing this for fun or profit? On Mon, Feb 6, 2017 at 3:40 PM Dirk Gorissen wrote: > Thanks Marcus & Martin for the responses. > > To clarify, Im working on a wildlife tracking problem but from the air > (drone). Im purely interested in

Re: [Discuss-gnuradio] intermittent pulse detection

Thanks Marcus & Martin for the responses. To clarify, Im working on a wildlife tracking problem but from the air (drone). Im purely interested in finding out if the pulse (which gets transmitted at a fixed interval of 1500ms) occurred or not. If it did, I know Im within some range of the animal

Re: [Discuss-gnuradio] intermittent pulse detection

Hi Dirk, nice to have you around, welcome to GNU Radio! I don't know your level of DSP knowledge, so please excuse if I either throw too many high-level concepts at you or assume you could want to read up on something that you already know. If something in my reply is unclear, please don't

Re: [Discuss-gnuradio] intermittent pulse detection

On 02/04/2017 11:39 PM, Dirk Gorissen wrote: > 1) 2.5 Msps gives me way more bandwidth than I neeed. Assuming, for > now, I only care about a single pulse frequency I really only need > ~1khz bandwidth. In the frequency domain I can directly decimate down > (with a big factor) to the 1-2 khz range

[Discuss-gnuradio] intermittent pulse detection

Fist of all, while Im a newbie to (gnu)radio, congrats to the dev team for a great piece of software. My question is about the need to detect a weak, noisy, short (10ms) pulse that occurs every 1.5 seconds. It is transmitted at a particular frequency (e.g., 150.22 MHz) but in practise I have