This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-sdr@lists.osmocom.org/.
o decode the VOR's morse code station ID. From that, I will have a shor= t list of VORs that I can currently receive. From those, if the geometry is= appropriate (I know the VORs positions from a database) I can calculate a = position.<u></u><u></u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal">The software then just round-robin tunes the VORs in range= and continually tries to calculate positions. If too many drop out, it ret= urns to the initial scan mode.<u></u><u></u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal">Not being able to receive this VOR or that VOR is not gene= rally a problem, but obviously, the more the better. With extra VORs I have= better options for choosing the closest ones or the ones with the best geo= metry.<u></u><u></u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal"><u></u> <u></u></p></div><div><p class=3D"MsoNormal">= This is actually quite difficult to test, because VORs can generally only b= e received line-of-sight -- which means in the air. I'm a private pilot= but I found that flying and noodling with a laptop is too much trouble. Fr= om my office window, on a high floor in Oakland, CA, I can receive one VOR = from the Oakland airport. And I have now discovered a ridge near my home wi= th a scenic overlook from which I can receive two.<u></u><u></u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal">I've tested the software enough to know that the initi= al scan function seems to work, and the morse decoding kind of works, but I= am not confident I'll get it to work very well. (One transmitter's= dit looks a lot like another's dah.) The nav signal decoding is simple= . (A 30 Hz AM modulated tone is phase compared with a 30 Hz tone FM modulat= ed at 9960 Hz. The phase obtained is the azimuth to the station.)<u></u><u>= </u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal"><u></u> <u></u></p></div><div><p class=3D"MsoNormal">= If I ever get this working, I looking forward to sharing it with the commun= ity. In the process of building this, I created a simple SDR toolkit of DSP= functions. It's like Gnuradio in concept, but 16b fixed-point, and has= no external dependencies, and C89, so is easier to build on weird and limi= ted platforms. It also has perl bindings. Compared to GR, it looks like the= work of a rank amateur just learning DSP, but I do like the concept of the= re being a GR-like library out there, lightweight and embedded-friendly.<u>= </u><u></u></p> </div><div><p class=3D"MsoNormal"><u></u> <u></u></p></div><div><p cla= ss=3D"MsoNormal"><u></u> <u></u></p></div><div><p class=3D"MsoNormal">= Regards,<u></u><u></u></p></div><div><p class=3D"MsoNormal">Dave J<u></u><u= ></u></p></div> <div><div><div><p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><u></u= > <u></u></p><div><p class=3D"MsoNormal">On Tue, Oct 22, 2013 at 3:06 = AM, jdow <<a href=3D"mailto:jdow at earthlink.net" target=3D"_blank">jdow at e= arthlink.net</a>> wrote:<u></u><u></u></p> <p class=3D"MsoNormal">He sent me two frequencies in private email. These w= ere in the FM<br>broadcast band (in the US). He probably needs to notch the= m out<br>in order to get adequate response.<br><br>As for wanting narrow ba= ndwidth - I am not quite sure why he thinks<br> that is a benefit. I use a large FFT (about 10 Hz per bin) and use<br>the z= oom control to see fine detail. (Different FFT settings suite<br>different = uses. This one seems to be a good compromise with my two<br>needs. I'm = too lazy to change it.)<br> <br>{^_^}<u></u><u></u></p><div><div><p class=3D"MsoNormal"><br><br><br>On = 2013/10/22 02:08, Sylvain Munaut wrote:<u></u><u></u></p><blockquote style= =3D"border:none;border-left:solid #cccccc 1.0pt;padding:0cm 0cm 0cm 6.0pt;m= argin-left:4.8pt;margin-right:0cm"> <p class=3D"MsoNormal">Effective filtering must occur between antenna and r= eceiver. All the<br>problems that a saturated preamp and ADC cause can&rsqu= o;t be repaired by<br>software. Never.<u></u><u></u></p></blockquote><p cla= ss=3D"MsoNormal" style=3D"margin-bottom:12.0pt"> <br>But his original problem is not with saturated preamps or ADC ... it= 9;s<br>aliasing ... and that can be solved in the digital domain provided<b= r>fast enough ADC.<br><br>Cheers,<br><br> Sylvain<br><br><u></= u><u></u></p> </div></div></div><p class=3D"MsoNormal"><u></u> <u></u></p></div></di= v></div></div></div><p class=3D"MsoNormal"><u></u> <u></u></p></div></= div></div></div></div></div></blockquote></div><br></div> --001a11346d7c0fd5fd04f20c4ef9--