> The I/Q plot show complex cross-correlation between two noise signals at > 100 MHz center frequency (2.4 MHz bandwidth noise). The phase of the signal > can be converted into time and Allan deviation, but I never did. I was just > happy to see a straight line.
I continued the measurement this morning after having the temperature of the dongles stabilized overnight: I gain a factor 10 stability on a 2 hour measurement: http://jmfriedt.sequanux.org/3allan.pdf Actually I just discovered something fascinating: I was contemplating which radio source would be best suited for the passive radar experiment. Not being able to find any suitable source while scanning the environment with a yagi antenna, I decided to tune to the 143.05 MHz frequency of the GRAVES [1] bistatic emitter which happens not to be too far away. To my great surprise, after replacing the quartz (drifting far too much) with a hydrogen maser referenced synthesized tuned to 28.8 MHz, I get amazing doppler shifted traces of reflectors between the emitter and my receiver. I didn't expect such a low quality receiver to be able to extract this signal: example of a waterfall trace at http://jmfriedt.sequanux.org/graves.pdf JM [1] https://en.wikipedia.org/wiki/Graves_%28system%29 -- JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe, 25000 Besancon, France _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
