Hi, I'm just using a simple script to dump data to disk. I then have another program that analyzes the files. It is not too complicated. The measurement equation is a convolution with the assumption that the target is stationary over ~20 ms and that the ground clutter is stationary over ~1 second.
My code is a mess at the moment and it depends on other unpublished libraries that I have written, which are also a mess. I might release this once I have cleaned it up a bit. juha On Thu, Sep 26, 2013 at 9:00 AM, M Dammer <i...@mdammer.net> wrote: > This is awesome. How did you analyze the data ? Is the software/source > (both grc setup and data analysis) available ? > Mark > > > On 25/09/13 23:23, Juha Vierinen wrote: > > I hooked up my dual coherent channel rtl_sdr dongle into two of our > passive radar antennas that we have here (log-periodic antennas pointing > North and South). After fine tuning gains and signal levels, I acquired > some FM radio data (WWLI 105.1 MHz). To my surprise, I got passive radar > echoes from airplanes when I analyzed the data. Passive radar is one of the > most challenging types of radar because the requirements for dynamic range > are larger than those for eg., pulsed radar, I really didn't expect much > from my test. > > I expect the $16 system to also be able to see specular meteor echoes > (typically stronger than airplanes) and ionospheric field aligned > irregularity echoes. Not bad for something that required about $10k-$100k > investment in a digital receivers ten years ago, and a $2k investment > yesterday. > > Visually, the rtl_sdr dongle system has a little bit more noise than the > usrp n200 with a tvrx2. And also, there is the hassle of aligning samples. > So I would still use the usrp if given a choice, as it does perform better > and requires no hacking. > > Here is the passive radar video I just made using my $16 dual channel > rtl_sdr (the timestamp is broken, but I just did the measurement an hour > ago): > http://youtu.be/KRqtqtCVRR0 > > For comparison, here is an example passive radar video of airplanes and > specular meteor echoes done using a usrp n200 + tvrx2. This was earlier, so > the targets aren't the same: > http://youtu.be/-k2ZuhAz0ac > > Does anyone know who manufactures these dongles, or who designed it? > > PS. I ordered a seven port usb hub, in anticipation of adding more > coherent channels (to do interferometry and maybe imaging). It seems that > every time I browse ebay, I end up ordering a few dongles. > > juha > > > _______________________________________________ > Discuss-gnuradio mailing > listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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